Fermented Foods · Fermented condiment
Soy Sauce and Tamari
Glycine max (soybean) fermented, usually with Triticum aestivum (wheat) · also called Soy sauce, soya sauce, shoyu, tamari
Soy sauce is a dark, salty seasoning made by fermenting soybeans, usually with wheat. Tamari is a similar sauce that USDA lists as made from soy. A tablespoon holds roughly 880 to 1,000 mg of sodium, and cutting salt lowers blood pressure in trials. No study of soy sauce itself for a health benefit was found. The main cautions are salt, soy and wheat allergy, wheat and gluten in most soy sauces, and MAOI antidepressants.
General information, not medical advice. Last substantive update · Not medically reviewed. A named clinician has not signed off on this page. How this page is made
About Soy Sauce and Tamari
Soy sauce is a salty, fermented seasoning made from soybeans, usually with wheat. Tamari is a similar sauce that USDA lists as made from soy. It is a food used by the spoonful, not a proven remedy: the best-documented point is its salt, and no study of soy sauce for a health benefit was found.
What it is
Soy sauce is a dark liquid made by fermenting soybeans, usually with wheat. A 2015 review says it is made in three ways: by fermentation, by acid hydrolysis of vegetable protein (acid-HVP), or by mixing the two. USDA lists two reference items: soy sauce made from soy and wheat (shoyu) and soy sauce made from soy (tamari).
USDA data, per 100 g: shoyu has 53 kcal, 8.14 g protein, 4.93 g carbohydrate and 5,490 mg sodium; tamari has 60 kcal, 10.5 g protein, 5.57 g carbohydrate and 5,590 mg sodium. One tablespoon (16 g for shoyu, 18 g for tamari) holds about 8.5 and 10.8 kcal, 1.3 and 1.9 g protein, and about 878 and 1,006 mg of sodium. A tablespoon adds only small amounts of any vitamin or mineral other than sodium.
Salt: the number to look at
The US Daily Value for sodium is under 2,300 mg a day, and FDA calls 20% of it or more per serving high. A tablespoon of shoyu is about 38% and a tablespoon of tamari about 44%, by our calculation from the USDA figures. WHO recommends adults take under 2,000 mg of sodium a day and names soy sauce among condiments that are often high in sodium.
Brands differ. A 2025 survey of 102 soy sauces in Malaysia found about 3,368 mg per 100 g in sweet soy sauces, 4,987 mg in salty and 5,710 mg in light soy sauces. In that study a reduced-sodium prototype (about 3,600 mg per 100 g) was liked by 52 tasters. Check the Nutrition Facts label.
What the research shows
No trial or large cohort study of soy sauce for blood pressure, heart disease, blood sugar, weight or cancer was found. The firm evidence is about salt: in 34 trials (3,230 adults), a modest cut in salt lowered blood pressure by 4.18 mmHg (top number) and 2.06 mmHg (bottom number) on average.
Pooled trials of fermented soy products found small average drops in fasting glucose (6.39 mg/dL), total cholesterol (5.0 mg/dL) and waist size (1.5 cm). The abstract does not list the foods, so soy sauce may not be among them. A 2026 umbrella review called the benefits of fermented soy products inconclusive and said some studies pointed to possible harm.
In the test tube, diluted soy sauce blocked the human enzymes MAO-A and MAO-B, and harman and norharman were found in commercial sauces. There is no result in people.
Wheat and gluten: what labels and tests can and cannot tell you
USDA lists regular soy sauce as made from soy and wheat, and USDA lists tamari as made from soy. We did not read a source on how much wheat shop-bought tamari holds, so check the label. FDA says "gluten-free" is a voluntary claim and has a rule for fermented and hydrolyzed foods.
A 2026 lab study of 15 soy sauces found gluten below the limit of the standard ELISA test, yet found small amounts of celiac-active peptides (0.2 to 0.5 mg/kg). The study does not say whether those amounts cause symptoms. A low gluten result also does not prove a sauce is safe for a person with wheat allergy, which is a different condition from celiac disease.
Food versus other soy products
Everything above is about soy sauce as a seasoning. Soy protein trials, isoflavone supplements, and whole soy foods such as tofu are different questions. Fermented foods are also not the same as probiotic supplements: ISAPP defines fermented foods as made through desired microbial growth and says they are distinct from probiotics. We found no source on live microbes in finished soy sauce.
At a glance
Traditional uses history, not proof
- Used as a seasoning and dipping sauce in many cuisines
- Long use as a seasoning is not proof that it treats any condition
Studied for research
- Salt and blood pressure, high certainty that less salt lowers blood pressure; soy sauce itself not tested and it is a caution, not a benefit
- Nutrients per spoonful, high certainty for the USDA values; almost all sodium
- Blood sugar, cholesterol and waist size, low certainty (fermented soy products, not soy sauce)
- Overall effects of fermented soy foods, insufficient evidence (inconclusive)
- MAO enzyme blocking by natural compounds, insufficient evidence (test tube only)
Main compounds
- Sodium
- Soy and wheat proteins
- Gluten and celiac-active peptides
- Histamine and tyramine
- Harman and norharman
- 3-MCPD (in some products)
- Free glutamate
Common forms
- Soy sauce made from soy and wheat (shoyu), USDA values read
- Tamari, USDA lists it as made from soy; shop products vary, so check the label for wheat
- Reduced-sodium, sweet, light and gluten-free soy sauces (not read in USDA data)
- Fermented, acid-hydrolysed or mixed sauces (all described in a review; the label may say which)
Research links: 2013 Cochrane review: salt reduction and blood pressure (34 trials) · 2026 lab study: celiac-active peptides in soy sauces · 1999 lab study: tyramine in soy products · Research Library · Genes & Biomarkers Library
What it is and its history
- Accepted scientific name
- Glycine max (L.) Merr. (soybean) with, in most soy sauce, Triticum aestivum L. (wheat)
- Naming authority
- GBIF accepted names for the two raw ingredients. Soy sauce itself is a processed food, not a plant.
- Common names
- Soy sauce (English); Soya sauce (English); Shoyu (Japanese); Tamari (Japanese); Salsa de soja (Spanish)
- Family or group
- Soybean is in the legume family (Fabaceae) and wheat in the grass family (Poaceae), as given by GBIF.
- Classification
- Plantae > Tracheophyta > Magnoliopsida > Fabales > Fabaceae > Glycine > Glycine max
- Native range
- Not verified from a source read.
- Habitat
- Not verified from a source read.
- What it looks like
- Roots: Not verified.; Stems: Not verified.; Leaves: Not verified.; Flowers: Not verified.
- Cultivation
- Not verified from a source read.
- Harvest and processing
- A 2015 review says soy sauce is made in three ways: fermented, acid-hydrolysed vegetable protein (acid-HVP), and mixtures of the two. A 2025 lab study identified Bacillus cereus and the yeast Millerozyma farinosa among microbes active in soy sauce fermentation, and a 2017 lab study notes that the two main raw materials are soybean and wheat and that heat treatment and filtration are part of making finished soy sauce. USDA calls the first item "soy sauce made from soy and wheat (shoyu)" and the second "made from soy (tamari)". The step-by-step process, koji mould, brewing times and tamari production were not read from a source.
- Look-alikes and adulterants
- Name: Miso, natto, tempeh and fermented tofu; Note: Other fermented soy foods with their own pages; they are solids and differ in salt, amines and nutrients.; Name: Fish sauce; Note: Another very salty fermented sauce, made from fish, not soy.; Name: Seasoning sauces and flavoured or sweet soy sauces; Note: Recipes differ; a Malaysian survey found sweet soy sauce had less sodium per 100 g than salty or light soy sauce.
- Sustainability and conservation
- Not assessed.
Photographs
Traditional use and history history, not clinical proof
| Tradition or era | Documented use | Source |
|---|---|---|
| Soy in the human diet | A 2026 umbrella review says soy has been a fundamental component of human diets for thousands of years. | p41327897 |
| Fermented foods in general | The 2021 ISAPP consensus says fermented foods have been consumed for thousands of years. It does not give a date for soy sauce. | p33398112 |
| Acid-hydrolysed soy sauce and 3-MCPD | A 2015 review says 3-MCPD was found in 1978 as a by-product of acid-HVP soy sauce. | p33401813 |
Traditional use shows how it was used. It does not show that it works or is safe today.
What is inside, and how it may work
What it contains and how those compounds act in cells and animals. Laboratory and animal mechanisms are not proven effects in people.
Main compounds
| Compound | Family | Where it is concentrated | Activity studied | Level of evidence |
|---|---|---|---|---|
| Sodium (salt) | mineral | Added in making USDA per 100 g: 5490 mg (shoyu), 5590 mg (tamari). Malaysian surveys: roughly 3,368 to 5,710 mg per 100 g depending on type. | Excess sodium raises blood pressure (WHO). 29 30 3 15 31 | Human data |
| Soy and wheat proteins | protein | Seed (soy) and grain (wheat) USDA per 100 g protein: 8.14 g (shoyu), 10.5 g (tamari) | Soy and wheat proteins are major allergens. Allergens are partly broken down in fermentation and heat treatment and filtration removed soluble soybean allergens in a lab study. 29 30 11 21 | Lab |
| Gluten and celiac-active peptides | protein fragments | Wheat grain Celiac-active peptides 0.2 to 0.5 mg/kg in 15 soy sauces; gluten below the ELISA limit of quantification | Gluten triggers the immune response in celiac disease. 17 1 | Lab |
| Histamine and tyramine (biogenic amines) | amines | Formed by microbes in the ferment No typical amount per spoonful found; the 1999 lab study found high tyramine in one soy sauce | Can cause headache and raised blood pressure in sensitive people and, for tyramine, with MAOI medicines. 20 14 16 | Lab |
| Harman and norharman (beta-carboline alkaloids) | alkaloids | Formed in the ferment Harman 243 ug/L and norharman 52 ug/L in commercial soy sauces (2023 lab study) | Blocked human MAO-A and MAO-B in the test tube. 5 | Laboratory research |
| 3-MCPD (3-chloropropane-1,2-diol) | processing contaminant | Formed by heating in acid-hydrolysed sauces Surveys range from not detected to tens of mg/kg depending on product; see the Safety tab | Reported carcinogenic, kidney-toxic and reproductively toxic in laboratory animals; classed as a possible carcinogen. 8 10 7 | Animal research |
| Free glutamate (umami) | amino acid | Released from protein Not found for soy sauce; FDA says free glutamate occurs naturally with sodium in soy extracts and other protein-breakdown ingredients | Chemically the same as the glutamate in MSG; FDA says added MSG is generally recognized as safe. 23 19 | Human data |
Mechanisms, receptors and pathways
| Target or pathway | Gene or receptor | What was found | Level |
|---|---|---|---|
| Sodium and blood pressure | Not specified in the sources read | WHO says excess sodium is a well-established cause of raised blood pressure; the Cochrane review found falls in blood pressure when salt was cut. 31 4 | Human data |
| Tyramine and monoamine oxidase (MAO) | Monoamine oxidase (the enzyme MAOI drugs block) | Tyramine in fermented foods comes from certain micro-organisms. With an MAOI, tyramine can raise blood pressure. A 2023 test-tube study found soy sauce itself blocks MAO-A and MAO-B, with harman as one contributor. 16 2 5 | Lab |
| Fermentation and allergens | Not specified | Fermentation partly breaks down soy and wheat allergens, but not completely in raw soy sauce; heat treatment and filtering matter. One reviewed study found a worse reaction to a fermented soy food. 11 6 | Lab |
| Amine-making microbes | hdc and tdc genes (histamine and tyramine formation) | Bacillus and a yeast in the ferment make histamine and tyramine; common gene tests missed many producers. 20 | Lab |
Absorption, metabolism and elimination
- Absorption
- Not found for soy sauce.
- Distribution
- Not found.
- Metabolism
- Not found. MAO is the enzyme that breaks down tyramine.
- Elimination
- Not found.
- Bioavailability
- Not established.
Isolated compounds versus whole extracts
Everything cited about health effects is either about salt in general, about fermented soy foods as a group, or about test-tube work. Soy sauce is a seasoning; soy protein trials, isoflavone supplements and whole soy foods such as tofu are different questions.
Nutritional composition
Nutrition from USDA FoodData Central (SR Legacy, last updated 4/1/2019; values read 2026-10-26 from USDA's public data feed). Soy sauce made from soy and wheat (shoyu, FDC 174277), per 100 g: 53 kcal, 8.14 g protein, 0.57 g fat, 4.93 g carbohydrate, 0.8 g fibre, 33 mg calcium, 1.45 mg iron, 74 mg magnesium, 166 mg phosphorus, 435 mg potassium, 5490 mg sodium, 0.87 mg zinc, 1.02 mg manganese, 2.2 mg niacin. One USDA tablespoon of 16 g (the 100 g values multiplied by 0.16): about 8.5 kcal, 1.3 g protein, 0.09 g fat, 0.8 g carbohydrate, 878 mg sodium (about 38% of the 2,300 mg US Daily Value), 70 mg potassium, 12 mg magnesium and 0.16 mg manganese. Soy sauce made from soy (tamari, FDC 174278), per 100 g: 60 kcal, 10.5 g protein, 0.1 g fat, 5.57 g carbohydrate, 0.8 g fibre, 20 mg calcium, 2.38 mg iron, 40 mg magnesium, 130 mg phosphorus, 212 mg potassium, 5590 mg sodium, 0.43 mg zinc, 0.499 mg manganese, 3.95 mg niacin. One USDA tablespoon of 18 g: about 10.8 kcal, 1.9 g protein, 1,006 mg sodium (about 44% of the Daily Value), 38 mg potassium, 7 mg magnesium. A teaspoon is 5.3 g (shoyu) or 6 g (tamari): about 291 mg and 335 mg of sodium. Brands differ: Malaysian surveys found about 3,368 mg (sweet) to 5,710 mg (light) of sodium per 100 g. A tablespoon gives only small amounts of any vitamin or mineral other than sodium. Reduced-sodium, sweet, flavoured and gluten-free soy sauces were not read in USDA data.
2 high certainty1 low certainty2 not enough evidence
What was looked at
The 5 benefits and uses checked for Soy Sauce and Tamari, each with how strong the evidence is. Tap one to open it.
- Salt content and blood pressure (a caution, not a benefit)High certainty
- What a spoonful provides (nutrient content)High certainty
- Blood sugar, cholesterol and waist size (fermented soy products, not soy sauce)Low certainty
- Overall health picture of fermented soy foodsNot enough evidence
- Natural compounds that block the MAO enzyme (test-tube only)Not enough evidence
Lab markers tracked in the studies
Systolic blood pressure (the top number)Diastolic blood pressure (the bottom number)Fasting blood glucoseTotal cholesterolWaist circumference
What is Soy Sauce and Tamari good for?
The studied questions and how strong the human evidence is for each. No study of soy sauce itself for a health benefit was found, so most rows are about salt or about fermented soy foods in general.
Benefits, one by one
Each card is a research question, not a promise. Tap a goal to filter. Open a card to see the studies, doses and limits.
Salt content and blood pressure (a caution, not a benefit)
High certaintySoy sauce is mostly a salty seasoning. By USDA data one tablespoon holds roughly 880 to 1,000 mg of sodium, about 38% to 44% of the 2,300 mg US Daily Value. Trials of cutting salt show blood pressure falls, so the salt in soy sauce is the main thing to weigh. No trial tested soy sauce itself.
5 studiesDietary salt in general, not soy sauce. Soy sauce sodium values are f…
Studies, doses and limits
What the trials found
A Cochrane review of 34 randomised trials (3,230 adults, at least 4 weeks) found that a modest salt cut (about 4.4 g of salt a day) lowered blood pressure by 4.18 mmHg (top number) and 2.06 mmHg (bottom number) on average, with larger falls in people with high blood pressure. No trial or cohort of soy sauce alone for blood pressure was found.
Results
Less salt, lower blood pressure: a firm finding about salt. Soy sauce is a concentrated source of salt, so cutting back on it lowers sodium, but whether that changes blood pressure for you depends on the rest of your diet.
Effect sizes as reported
Salt reduction: systolic -4.18 mmHg (95% CI -5.18 to -3.18), diastolic -2.06 mmHg (-2.67 to -1.45). High blood pressure: -5.39 and -2.82 mmHg. Normal blood pressure: -2.42 and -1.00 mmHg.
Why this rating
High that a modest fall in salt lowers blood pressure (34 trials; the abstract gives no GRADE, so this is our reading, with large differences between trials). Not tested for soy sauce itself, so the link to soy sauce is by its sodium content.
Form and dose studied
Dietary salt in general, not soy sauce. Soy sauce sodium values are from USDA data (Nutrition tab figures) and from shop surveys.
Who was studied
Adults with and without high blood pressure; both sexes and different ethnic groups.
Limits
The evidence is about salt, not about soy sauce. Differences between trials were large. Sodium in a real bottle varies by brand and type.
Why researchers looked
WHO names soy sauce among condiments that are often high in sodium, and sodium is a well-known driver of blood pressure.
Traditional use
Soy sauce is a long-used seasoning in many cuisines. Long use as a seasoning is not evidence that it helps any condition.
Proposed mechanism Authoritative guidance
Sodium makes the body hold fluid, and WHO says excess sodium is a well-established cause of raised blood pressure. This is established physiology, not something shown for soy sauce in particular.
A proposed mechanism does not show that the effect happens in people.
See the Safety tab for kidney disease, children and the sodium limits stated by WHO and FDA.
What a spoonful provides (nutrient content)
High certaintyPer tablespoon, soy sauce provides little besides sodium. USDA lists about 8.5 kcal and 1.3 g of protein for soy sauce made with wheat (shoyu), and about 10.8 kcal and 1.9 g of protein for tamari. Minerals such as potassium, magnesium, iron and manganese are present in small amounts.
2 studiesUSDA SR Legacy items 174277 (soy and wheat) and 174278 (tamari, made …
Studies, doses and limits
What the trials found
No trial was read showing that eating soy sauce corrects any nutrient shortfall.
Results
Per 100 g, shoyu has 8.14 g protein and tamari 10.5 g, but a tablespoon is only 16 to 18 g, so a spoonful adds only about 1 to 2 g of protein and small amounts of minerals. The big number in the table is sodium.
Effect sizes as reported
USDA per tablespoon (100 g values multiplied by the portion weight): shoyu (16 g) 8.5 kcal, 1.3 g protein, about 878 mg sodium, 70 mg potassium; tamari (18 g) 10.8 kcal, 1.9 g protein, about 1,006 mg sodium, 38 mg potassium.
Why this rating
High that the food contains these amounts on paper (USDA data for two reference items). Not a health effect, and real products differ by brand and recipe.
Form and dose studied
USDA SR Legacy items 174277 (soy and wheat) and 174278 (tamari, made from soy). Reduced-sodium, sweet, light and flavoured soy sauces were not read in USDA data.
Who was studied
General adult diet.
Limits
Reference-table values, not a particular bottle. USDA calls the tamari item "made from soy", but shop tamari can differ, so check the label.
Why researchers looked
People ask whether a fermented soy seasoning adds nutrition, so the USDA tables are the right place to look.
Traditional use
Soy sauce is eaten by the spoonful as a seasoning, so portions are small.
Proposed mechanism Nutrient database
These are nutrient amounts in the food, taken from USDA tables.
A proposed mechanism does not show that the effect happens in people.
Sodium, wheat and soy allergy are the main safety points; see the Safety tab.
Blood sugar, cholesterol and waist size (fermented soy products, not soy sauce)
Low certaintyPooled trials of fermented soy products found small average drops in fasting blood sugar, total cholesterol, waist size and visceral fat. The abstract does not say which fermented soy foods were used, so soy sauce is not shown to be one of them.
2 studiesFermented soy products; foods, amounts and trial lengths not given in…
Studies, doses and limits
What the trials found
A 2025 pooled analysis of 15 randomised trials found, compared with controls, body mass index 0.14 kg/m2 lower, waist 1.50 cm smaller, visceral fat smaller, fasting glucose 6.39 mg/dL lower and total cholesterol 5.0 mg/dL lower. Other markers did not change significantly.
Results
Small average improvements on some markers from fermented soy foods as a group. Several are tiny, and nothing in the abstract tells us the trials used soy sauce.
Effect sizes as reported
BMI -0.14 kg/m2 (95% CI -0.28 to -0.01); waist -1.50 cm (-2.94 to -0.07); visceral fat -692.17 mm2 (-1011.58 to -372.77); fasting glucose -6.39 mg/dL (-10.38 to -2.40); total cholesterol -5.0 mg/dL (-6.60 to -3.39).
Why this rating
Low for soy sauce: pooled trials exist, but they are of fermented soy products as a group, the foods are not listed in the abstract, effects are small, and trial quality is not stated in the abstract. The next row (an umbrella review) calls the wider benefit of fermented soy inconclusive.
Form and dose studied
Fermented soy products; foods, amounts and trial lengths not given in the abstract.
Who was studied
Adults in 15 trials; details not given in the abstract.
Limits
Not specific to soy sauce. Small effects and wide intervals. Eating soy sauce is also eating salt, which this analysis does not address.
Why researchers looked
Fermented soy foods such as natto, miso and tempeh are eaten widely, and researchers pooled trials of them for metabolic markers.
Traditional use
Fermented soy foods are staples in several cuisines. Long use as food is not proof that they treat any condition.
Proposed mechanism Not established
Not established. The abstract proposes no specific mechanism.
A proposed mechanism does not show that the effect happens in people.
Soy sauce is high in sodium; see the Safety tab.
Overall health picture of fermented soy foods
Not enough evidenceAn umbrella review of meta-analyses found that eating soy foods overall looks more beneficial than harmful, but for fermented soy products the benefits were inconclusive and some studies hinted at possible harm.
1 studiesSoy foods including fermented soy products.
Studies, doses and limits
What the trials found
The 2026 umbrella review combined 23 meta-analyses of observational studies (39 outcomes) and 1 meta-analysis of randomised trials (4 outcomes). Observational reviews cannot prove cause.
Results
Soy foods as a whole looked more helpful than harmful, especially for cancer and cardiometabolic disease. Fermented soy products did not share that clear picture.
Effect sizes as reported
No numbers in the abstract.
Why this rating
Insufficient for fermented soy products, which the authors call inconclusive. Soy sauce is not named in the abstract.
Form and dose studied
Soy foods including fermented soy products.
Who was studied
Mostly general populations in observational meta-analyses.
Limits
Mostly observational reviews. Fermented soy is a broad group (natto, miso, tempeh, sauces and more).
Why researchers looked
Researchers wanted a single overview of what pooled studies say about eating soy foods.
Traditional use
Soy has been part of human diets for thousands of years, according to the review.
Proposed mechanism Not stated
Not covered in the abstract.
A proposed mechanism does not show that the effect happens in people.
The authors say some studies indicated possible adverse effects of fermented soy; the abstract does not say which.
Natural compounds that block the MAO enzyme (test-tube only)
Not enough evidenceIn the lab, diluted soy sauce blocked the human enzymes MAO-A and MAO-B. Two naturally formed compounds, harman and norharman, were found in commercial soy sauces. No result in people was found.
1 studiesDiluted soy sauce and soy sauce extracts, test tube.
Studies, doses and limits
Results
A test-tube result. It does not show that eating soy sauce changes MAO in the body, mood or blood pressure.
Effect sizes as reported
Harman 243 micrograms per litre and norharman 52 micrograms per litre in commercial soy sauces; harman blocked MAO-A by 44% at 0.4 micromolar in the test tube.
Why this rating
Insufficient: laboratory work only, with no human result.
Form and dose studied
Diluted soy sauce and soy sauce extracts, test tube.
Limits
Test-tube enzymes only. The author says other substances may also play a part.
Why researchers looked
MAO breaks down brain chemicals and some food amines, and drugs that block it are used as antidepressants.
Proposed mechanism Laboratory research
The author proposes that beta-carboline alkaloids (harman and norharman) formed during making and cooking block the MAO enzyme.
A proposed mechanism does not show that the effect happens in people.
This is a reason people on MAOI medicines are asked to talk to their prescriber; see the Safety tab.
Connections to the rest of health
How Soy Sauce and Tamari connects to the rest of our health knowledge graph. Every link says what kind of connection it is. A safety link (for example to the liver) is a warning, not a benefit. A study that merely mentions a topic never creates a benefit link.
Explore every connection: goals, body systems, organs, symptoms, genes
A. Wellness goals
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Blood Pressure Support | High certainty | Salt content and blood pressure (a caution, not a benefit): Soy sauce is mostly a salty seasoning. By USDA data one tablespoon holds roughly 880 to 1,000 mg of sodium, about 38% to 44% of the 2,300 mg US Daily Value. Trials of cutting salt show blood pressure falls, so the salt in soy sauce is the main thing to weigh. No trial tested soy sauce itself. | 4 31 24 29 30 | |
| Heart Health | High certainty | Salt content and blood pressure (a caution, not a benefit): Soy sauce is mostly a salty seasoning. By USDA data one tablespoon holds roughly 880 to 1,000 mg of sodium, about 38% to 44% of the 2,300 mg US Daily Value. Trials of cutting salt show blood pressure falls, so the salt in soy sauce is the main thing to weigh. No trial tested soy sauce itself. | 4 31 24 29 30 | |
| Blood Sugar Balance | Low certainty | Blood sugar, cholesterol and waist size (fermented soy products, not soy sauce): Pooled trials of fermented soy products found small average drops in fasting blood sugar, total cholesterol, waist size and visceral fat. The abstract does not say which fermented soy foods were used, so soy sauce is not shown to be one of them. | 12 9 | |
| Cholesterol Balance | Low certainty | Blood sugar, cholesterol and waist size (fermented soy products, not soy sauce): Pooled trials of fermented soy products found small average drops in fasting blood sugar, total cholesterol, waist size and visceral fat. The abstract does not say which fermented soy foods were used, so soy sauce is not shown to be one of them. | 12 9 |
B. Body systems
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Cardiovascular System | Biological association | High certainty | Studied for: Salt content and blood pressure (a caution, not a benefit) Studied for: Blood sugar, cholesterol and waist size (fermented soy products, not soy sauce) | 4 31 24 29 30 12 9 |
| Endocrine System | Biological association | Low certainty | Studied for: Blood sugar, cholesterol and waist size (fermented soy products, not soy sauce) | 12 9 |
E. Health conditions
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| High blood pressure (essential hypertension) | Documented risk | High sodium raises blood pressure and soy sauce is a high-sodium condiment. A caution, not a treatment. Preparation or compound: Sodium in soy sauce |
31 4 29 | |
| Celiac disease | Adverse effect or risk | Documented risk | Regular soy sauce is made with wheat; a 2026 lab study found celiac-active peptides even when the gluten test read below its limit. Preparation or compound: Wheat in regular soy sauce |
29 17 |
| Food allergy | Adverse effect or risk | Documented risk | Soy and wheat are major US food allergens. Preparation or compound: Soy and wheat proteins |
21 11 |
| Wheat hypersensitivity | Adverse effect or risk | Documented risk | A low gluten test result does not prove a sauce is safe for a person with wheat allergy. Preparation or compound: Wheat in regular soy sauce |
21 17 |
| Chronic kidney disease | Adverse effect or risk | Documented risk | NIDDK names soy sauce among high-sodium sauces for people with chronic kidney disease. Preparation or compound: Sodium in soy sauce |
28 |
| MAOI antidepressants | Drug or supplement interaction | Reported interaction | NCCIH reports dangerously high blood pressure with high-tyramine soy products and MAOIs; a 1999 lab study found high tyramine in one soy sauce. Preparation or compound: Tyramine in some soy sauces |
27 16 2 |
I. Biomarkers
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Systolic blood pressure (the top number) | Biological association | High certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 4 |
| Diastolic blood pressure (the bottom number) | Biological association | High certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 4 |
| Fasting blood glucose | Biological association | Low certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 12 |
| Total cholesterol | Biological association | Low certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 12 |
| Waist circumference | Biological association | Low certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 12 |
K. Biological pathways
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Sodium | Preliminary mechanism | Human | Soy sauce is a concentrated source of sodium; WHO and FDA give limits. | 29 30 31 4 |
| Tyramine and histamine | Preliminary mechanism | Lab | Biogenic amines made by microbes in fermented foods; relevant to MAOI medicines and sensitive people. | 20 14 16 |
| Gluten | Preliminary mechanism | Lab | Wheat gluten and celiac-active peptides in soy sauce made with wheat. | 17 1 |
L. Active compounds
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Sodium (salt) | Biological association | Human | Excess sodium raises blood pressure (WHO). Preparation or compound: Added in making |
29 30 3 15 31 |
| Soy and wheat proteins | Biological association | Lab | Soy and wheat proteins are major allergens. Allergens are partly broken down in fermentation and heat treatment and filtration removed soluble soybean allergens in a lab study. Preparation or compound: Seed (soy) and grain (wheat) |
29 30 11 21 |
| Gluten and celiac-active peptides | Biological association | Lab | Gluten triggers the immune response in celiac disease. Preparation or compound: Wheat grain |
17 1 |
| Histamine and tyramine (biogenic amines) | Biological association | Lab | Can cause headache and raised blood pressure in sensitive people and, for tyramine, with MAOI medicines. Preparation or compound: Formed by microbes in the ferment |
20 14 16 |
| Harman and norharman (beta-carboline alkaloids) | Biological association | In vitro | Blocked human MAO-A and MAO-B in the test tube. Preparation or compound: Formed in the ferment |
5 |
| 3-MCPD (3-chloropropane-1,2-diol) | Biological association | Animal | Reported carcinogenic, kidney-toxic and reproductively toxic in laboratory animals; classed as a possible carcinogen. Preparation or compound: Formed by heating in acid-hydrolysed sauces |
8 10 7 |
| Free glutamate (umami) | Biological association | Human | Chemically the same as the glutamate in MSG; FDA says added MSG is generally recognized as safe. Preparation or compound: Released from protein |
23 19 |
Each connection is stored with the ingredient, the connected record, the kind of connection, the evidence status, the supporting studies, the preparation or compound involved, and a review date (last reviewed October 26, 2026).
The evidence
The research centre for Soy Sauce and Tamari. Every record here was checked against PubMed or the publisher's page; we never list a study we have not verified.
Evidence by outcome
Bars show how many studies we found for each outcome, not how well it works. People are added up across trials only (reviews are not added, to avoid double counting).
How we rate evidence
High certainty
Several well-run trials or reviews agree; further research is unlikely to change the picture much.
Moderate certainty
Good trials point the same way, but some doubt remains.
Low certainty
Small, short or inconsistent trials. The finding could change with better research.
Very low certainty
Very little or very weak human data. Treat as a possibility only.
Mixed findings
Trials or reviews disagree with each other.
Not enough evidence
Not enough human research to say either way.
Evidence against
Good research found no benefit, or found harm.
We take the reviewers' own risk-of-bias and GRADE statements where they exist, and otherwise judge from study size, design, consistency, directness and whether a product matches what is sold. Many publications do not make evidence high. Method note: We started from our existing soy sauce summary, re-checked nutrition against USDA FoodData Central, read the health agency pages (NCCIH, FDA, WHO, NIDDK) and re-read PubMed abstracts for the reviews, surveys and lab studies cited. Only abstracts were read for studies. Items we could not verify are flagged in the research gaps.
Study library: every study we checked 31
| Study | Design | People | Product, dose, length | Result |
|---|---|---|---|---|
| Akhondi 2025 Gluten-Associated Medical Problems. · PMID 30860740 |
Narrative review n/a |
StatPearls study guide on gluten-related conditions | Gluten Wheat, barley, rye and derivatives |
Says gluten is found in wheat, barley, rye and some other grains, and commonly in imitation meats, beer, soy sauce, ice cream and ketchup, often through gluten-based stabilisers. It describes celiac disease, non-celiac gluten sensitivity, gluten ataxia and dermatitis herpetiformis. No numbers used here (Not applicable) Methods, limits and fundingOutcomes: Which foods contain gluten and which conditions it relates to Limitations: A general teaching guide. It names soy sauce in one sentence and does not measure the gluten in any product. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Gillman 2018 A reassessment of the safety profile of monoamine oxidase inhibitors: elucidating tired old tyramine myths. J Neural Transm (Vienna) · PMID 30255284 · DOI |
Narrative review n/a |
Review of over 150 recent papers on tyramine in foods and MAOI safety | MAOI diet (tyramine in foods) Foods including fish and soy sauces |
The author says modern foods contain much less tyramine than in the past, that few foods now contain problematic amounts, and that the risk of harm from the blood-pressure surge has been overstated. Fish and soy sauces are among the foods reviewed. He adds that people differ in how strongly they react, so a doctor's knowledge and care are still needed. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Tyramine content of modern foods and blood-pressure risk with MAOIs Limitations: A single-author narrative review. The abstract does not give soy sauce values, so it cannot tell us how much tyramine a given bottle holds. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Harun 2025 Reformulation of soy sauce to reduce sodium content and assessment of manufacturer readiness, consumer acceptance, and shelf life. Sci Rep · PMID 41315354 · DOI |
Other n/a |
102 102 soy sauces from Malaysian supermarkets (sodium analysis) plus interviews and a sensory test with 52 consumers |
Soy sauce, and reduced-sodium soy sauce prototypes Soy sauce as sold Shelf-life test of one year (accelerated) |
Salty soy sauces averaged 4,987 mg of sodium per 100 g, light soy sauces 5,710 mg and sweet soy sauces 3,368 mg. A prototype with 9% salt plus yeast extract (about 3,600 mg sodium per 100 g) was preferred by the tasters and stayed shelf-stable for one year. Salty 4987 +/- 1429; light 5710 +/- 1488; sweet 3368 +/- 863 mg/100 g (Not applicable) Methods, limits and fundingOutcomes: Sodium content, manufacturer readiness, consumer liking and shelf life Limitations: A product-development study in one country with 52 tasters. Reduced-sodium sauces in shops were not tested. Funding and conflicts: Authors declared interests: two are unpaid members of salt-reduction campaign groups. No industry funding stated in the abstract. Read: abstract |
| He 2013 Effect of longer-term modest salt reduction on blood pressure. Cochrane Database Syst Rev · PMID 23633321 · DOI |
Systematic review meta analysis |
3230 34 randomised trials, 3,230 adults, each at least 4 weeks |
Modest salt reduction (not soy sauce) Dietary salt Average fall in salt intake about 4.4 g a day At least 4 weeks · vs Usual salt intake |
A modest cut in salt for 4 weeks or more lowered blood pressure in people with and without high blood pressure. The fall was larger in people with high blood pressure. There was no significant change in blood fats. The review is about salt, not about soy sauce. Systolic -4.18 mmHg; diastolic -2.06 mmHg (all people). People with high blood pressure: -5.39 and -2.82 mmHg. People with normal blood pressure: -2.42 and -1.00 mmHg (Systolic -5.18 to -3.18; diastolic -2.67 to -1.45 (all people)) Methods, limits and fundingOutcomes: Blood pressure, hormones and blood fats Limitations: Differences between trials were large (I2 75% for systolic). It measures salt, not a particular food. Funding and conflicts: Competing interests: none known. Read: abstract |
| Herraiz 2023 β-Carboline Alkaloids in Soy Sauce and Inhibition of Monoamine Oxidase (MAO). Molecules · PMID 36985694 · DOI |
Laboratory study n/a |
Commercial soy sauces and soy sauce extracts tested on human MAO enzymes in the test tube | Diluted soy sauce and extracts Soy sauce Soy sauce diluted to one third Test tube |
Diluted soy sauce and its extracts blocked human MAO-A and MAO-B in the test tube. Harman and norharman, naturally formed compounds, were found in commercial soy sauces (243 and 52 micrograms per litre). Harman blocked MAO-A in the test tube (44% inhibition at 0.4 micromolar). The author says soy sauce is a dietary source of MAO-blocking compounds. Harman 243 ug/L; norharman 52 ug/L; MAO-A 44% inhibition by harman at 0.4 uM (Not applicable) Methods, limits and fundingOutcomes: Blocking of the human enzymes MAO-A and MAO-B, and levels of harman and norharman Limitations: Test-tube work only. It does not show any effect on MAO in the body or on mood or blood pressure. The abstract does not give the number of sauces tested; the existing summary said seven. Funding and conflicts: Author declared no conflict of interest. Read: abstract |
| Hyseni 2025 The role of fermented foods in managing food allergies in children and adults: a systematic review. Front Nutr · PMID 41561179 · DOI |
Systematic review |
10 human studies of fermented foods and food allergy (558 records screened) | Fermented foods (soy products, baked goods, fruit drinks, oat drinks, dairy) Mixed fermented foods |
Several studies reported lower allergenicity linked to fermentation breaking down gluten or soy proteins. In one case, eating a fermented food made the allergic reaction worse, which the authors think was due to compounds made during soy fermentation. Most studies had important methodological limits and the authors say the evidence is too limited for firm conclusions. No pooled numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Allergic response to fermented foods Limitations: Mixed foods and study types. It does not single out soy sauce. One author is employed by a company (VetAgro Sup); the others declared no conflicts. Funding and conflicts: One author employed by VetAgro Sup; the rest declared no commercial or financial relationships. Read: abstract |
| Jang 2020 Assessment of estimated daily intake of 3-monochloropropane-1,2-diol from soy sauce in Korea. Food Sci Biotechnol · PMID 33282433 · DOI |
Laboratory analysis n/a |
31 31 soy sauces from the Korean market (2017 market share) |
Soy sauce Soy sauce as sold |
3-MCPD ranged from not detected to 54.97 micrograms per kg (mean 11.62). Seven of 31 sauces (23%) were above Korea's limit of 20 micrograms per kg. Estimated intake was 1.22 ng per kg body weight for average consumers and 4.47 ng for high consumers, which is 0.03 to 0.11% of the 4 microgram per kg provisional maximum tolerable daily intake. The authors call exposure from soy sauce of low concern in Korea. Mean 11.62 ug/kg; 7 of 31 above 20 ug/kg; intake 0.03 to 0.11% of the PMTDI (Not applicable) Methods, limits and fundingOutcomes: 3-MCPD level and estimated daily intake Limitations: A 2020 survey of one country's market. The limit and intake figures are from the study abstract; we did not read the JECFA documents themselves. Funding and conflicts: Authors declared no conflict of interest. Read: abstract |
| Lee 2015 3-Chloropropane-1,2-diol (3-MCPD) in Soy Sauce: A Review on the Formation, Reduction, and Detection of This Potential Carcinogen. Compr Rev Food Sci Food Saf · PMID 33401813 · DOI |
Narrative review n/a |
Review of 3-MCPD in soy sauce | Soy sauce (fermented, acid-hydrolysed vegetable protein, and mixed types) Soy sauce |
Soy sauce comes in three types: fermented, acid-hydrolysed vegetable protein (acid-HVP) and mixtures. 3-MCPD is a heat-formed contaminant first found in 1978 as a by-product of acid-HVP soy sauce. In laboratory animals it has been reported to be carcinogenic, to harm the kidney and to harm reproduction. It is classed as a possible carcinogen and legal limits exist nationally and internationally. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: 3-MCPD formation, toxicity, reduction and detection Limitations: A 2015 review focused on production and testing. Findings on toxicity are from animal studies. The abstract does not give amounts in fermented-only sauces. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Li 2026 Soy Foods Consumption and Multiple Health Outcomes: An Umbrella Review of Meta-Analyses. Mol Nutr Food Res · PMID 41327897 · DOI |
Umbrella review |
23 meta-analyses of observational studies (39 outcomes) and 1 meta-analysis of trials (4 outcomes) | Soy foods including fermented soy products Soy foods as eaten · vs Lower intake |
Overall, eating soy foods was found more beneficial than harmful, especially for cancer and cardiometabolic disease. But the benefits of fermented soy products were inconclusive, and some studies suggested possible adverse effects. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Many health outcomes (cancer, cardiometabolic disease and others) Limitations: It combines mostly observational reviews, which cannot prove cause. It does not name soy sauce in the abstract. Funding and conflicts: Funded by a national public-health programme in China. Authors declared no commercial conflict. Read: abstract |
| Macarthur 2000 3-monochloropropane-1,2-diol (3-MCPD) in soy sauces and similar products available from retail outlets in the UK. Food Addit Contam · PMID 11271703 · DOI |
Laboratory analysis n/a |
40 40 soy sauces and similar products bought in UK shops |
Soy sauce and similar products Soy sauce as sold |
3-MCPD was undetectable in 21 of 40 samples (52%). Five samples had very low levels (0.01 to 0.02 mg/kg), five (13%) had 0.020 to 1 mg/kg and nine (23%) had more than 1 mg/kg, the highest being 30.5 mg/kg. The survey was prompted by reports of up to 124 mg/kg in sauces in several European countries. 9 of 40 above 1 mg/kg; highest 30.5 mg/kg (Not applicable) Methods, limits and fundingOutcomes: 3-MCPD levels compared with a recommended limit of 0.01 mg/kg Limitations: A survey from about 2000 of products on UK shelves then; the abstract does not say which were fermented and which were acid-hydrolysed. Today's products may differ. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Magishi 2017 Degradation and removal of soybean allergen in Japanese soy sauce. Mol Med Rep · PMID 28656270 · DOI |
Laboratory study n/a |
Soy sauce at different stages of making, tested with rabbit antibody and serum from 2 children with soybean allergy | Japanese soy sauce (raw and finished) Soy sauce at stages of production |
Soybean allergens were gradually broken down during fermentation but not completely in raw soy sauce. Heat treatment turned the soluble allergens into insoluble ones, and filtering then removed them. The authors say heat treatment and filtration matter for lowering allergy risk. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Soybean allergens remaining at each stage Limitations: A lab immunoblot study using serum from only two allergic children. It does not show that any bottle is safe for a person with soy allergy, and the abstract does not cover wheat allergens. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Maleki Sedgi 2025 Effect of fermented soybean on metabolic outcomes, anthropometric indices, and body composition: a systematic review and meta-analysis of clinical trials. Food Funct · PMID 39763426 · DOI |
Systematic review meta analysis |
15 randomised trials of fermented soy products (searched to March 2024) | Fermented soy products (the abstract does not list which foods) Fermented soy foods · vs Control groups |
Fermented soy gave small average improvements in body mass index, waist, visceral fat, fasting glucose and total cholesterol compared with controls. Other markers did not change significantly. BMI -0.14 kg/m2; waist -1.50 cm; visceral fat -692.17 mm2; fasting glucose -6.39 mg/dL; total cholesterol -5.0 mg/dL (BMI -0.28 to -0.01; waist -2.94 to -0.07; visceral fat -1011.58 to -372.77; glucose -10.38 to -2.40; total cholesterol -6.60 to -3.39) Methods, limits and fundingOutcomes: Body mass index, waist, visceral fat, fasting glucose, total cholesterol and other markers Limitations: The abstract does not say which fermented soy foods were used, so soy sauce may not be among them. Some effects are tiny and some intervals nearly touch zero. Quality of the trials and differences between them are not stated in the abstract. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Marco 2021 The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on fermented foods. Nat Rev Gastroenterol Hepatol · PMID 33398112 · DOI |
Narrative review n/a |
ISAPP expert panel consensus (September 2019) | Fermented foods (definition) Fermented foods |
The panel defined fermented foods and beverages as foods made through desired microbial growth and enzymatic conversions of food components, and said they are distinct from probiotics. It also reviewed safety, risks and possible health benefits. Not applicable (Not applicable) Methods, limits and fundingOutcomes: Definition of fermented foods and how they differ from probiotics Limitations: A consensus statement, not a trial. The abstract does not say whether finished soy sauce holds live microbes. Funding and conflicts: Some panel members reported paid consulting, speaking or advisory work for food and dairy companies (declared in the paper). Read: abstract |
| Saha Turna 2024 A review of biogenic amines in fermented foods: Occurrence and health effects. Heliyon · PMID 38304783 · DOI |
Narrative review n/a |
Review of biogenic amines in fermented foods | Fermented foods (general) Fermented foods |
Several fermented foods may contain histamine, tyramine or phenylethylamine above documented toxic levels. High intakes are linked with migraines, raised blood pressure and fast heartbeat. The authors say harm can occur at levels a hundred times below suggested toxic doses, depending on a person's sensitivity, alcohol and certain medicines. No numbers used here (Not applicable) Methods, limits and fundingOutcomes: Biogenic amines (histamine, tyramine and others), health effects and toxic levels Limitations: A review of fermented foods in general. The abstract does not name soy sauce. Funding and conflicts: Authors declared no competing interests. Read: abstract |
| Shahar 2019 Sodium content in sauces-a major contributor of sodium intake in Malaysia: a cross-sectional survey. BMJ Open · PMID 31133578 · DOI |
Other n/a |
233 233 sauces in seven top supermarkets in Kuala Lumpur, Malaysia (2017) |
Sauces, including 54 soy sauces Sauces as sold (label data) |
Light/thin soy sauce averaged 5,116 mg of sodium per 100 g and salty soy sauce 4,780 mg per 100 g, among the highest of any sauce. Almost half of the 233 sauces gave no sodium information on the label. Light soy sauce 5116 +/- 2084 mg/100 g; salty soy sauce 4780 +/- 988 mg/100 g (Not applicable) Methods, limits and fundingOutcomes: Sodium content from labels Limitations: Label information from Malaysia, not lab measurement, and only the sauces that listed sodium. Other countries' products can differ. Funding and conflicts: Competing interests: none declared. Read: abstract |
| Shulman 1999 Refining the MAOI diet: tyramine content of pizzas and soy products. J Clin Psychiatry · PMID 10192596 |
Laboratory analysis n/a |
Pizzas, soy sauces and other soybean products tested in the lab | Soy sauces and other soybean products Soy sauce as sold |
No significant tyramine in any pizza. Soy products varied a lot: clinically significant tyramine in tofu stored for a week, and high tyramine in one of the soy sauces. The authors advised that all soybean products, especially soy sauce and tofu, be avoided on MAOIs. No numbers in the abstract (Not applicable) Methods, limits and fundingOutcomes: Tyramine content (the authors treated a level of 6 mg or less as safe) Limitations: A 1999 lab analysis, not a trial and not a report of harm. The abstract does not say how many sauces were tested or which brands. Foods and recipes have changed since, and a 2018 review says the risk has been overstated. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Tissen 2026 Proteomics Analysis of Celiac Disease-Active Peptides in Food Products with Partially Hydrolyzed Gluten. J Agric Food Chem · PMID 41525254 · DOI |
Laboratory analysis n/a |
15 barley malt extracts, 7 barley malt vinegars and 15 soy sauces | Soy sauces (15 products) Soy sauce as sold |
Celiac-active peptides were found in the soy sauces at 0.2 to 0.5 mg/kg. The standard ELISA gluten test read below its limit of quantification in the soy sauces, even though peptides were present. The authors say this shows the need for a fuller risk assessment of foods with partly broken-down gluten. Soy sauce peptides 0.2 to 0.5 mg/kg (Not applicable) Methods, limits and fundingOutcomes: Celiac-disease-active gluten peptides measured by mass spectrometry, and gluten by the R5c ELISA test Limitations: A lab measurement of products, not a test in people with celiac disease. It does not say whether these amounts cause symptoms. The abstract does not say which brands or whether any were labelled gluten-free. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Wong 2020 Estimation of the dietary intake and risk assessment of food carcinogens (3-MCPD and 1,3-DCP) in soy sauces by Monte Carlo simulation. Food Chem · PMID 31869642 · DOI |
Laboratory analysis n/a |
43 43 foods from the Malaysian market, including soy-based sauces |
Soy sauces and other seasonings Soy-based sauces as sold |
3-MCPD ranged from not detectable to 0.1223 mg/kg across the foods. The highest levels were found in chicken seasoning cubes, above Malaysia's limit. Estimated intakes of 3-MCPD and 1,3-DCP at the 50th, 95th and 99th percentiles were below 4 micrograms per kg body weight a day, the limit recommended by JECFA in 2016. The authors concluded soy sauce intake in Malaysia does not present a health risk. Foods ranged from not detectable to 0.1223 mg/kg 3-MCPD (Not applicable) Methods, limits and fundingOutcomes: 3-MCPD and 1,3-DCP levels and intake risk (Monte Carlo simulation) Limitations: A national survey and a modelled risk estimate. The abstract highlights seasoning cubes rather than soy sauce itself as exceeding the limit. Funding and conflicts: Funding is not stated in the abstract. Read: abstract |
| Zanfirescu 2019 A review of the alleged health hazards of monosodium glutamate. Compr Rev Food Sci Food Saf · PMID 31920467 · DOI |
Narrative review mixed |
Review of preclinical studies and clinical trials on monosodium glutamate (MSG) | Monosodium glutamate Added MSG |
Animal studies linked MSG to many harms, but the authors found methodological flaws and said they have limited relevance to usual food intake. They found little supporting evidence for MSG hypersensitivity (sometimes called Chinese restaurant syndrome). They say better human studies are needed, accounting for both added and naturally occurring glutamate. No numbers used here (Not applicable) Methods, limits and fundingOutcomes: Alleged health hazards of MSG Limitations: It reviews added MSG, not the glutamate naturally freed in a fermented sauce. It does not mention soy sauce in the abstract. Funding and conflicts: Authors declared no affiliation or conflict. Read: abstract |
| Zhang 2025 Isolation and Characterizations of Histamine- and Tyramine-Producing Strains Isolated from Fermented Soybean Food: Soy Sauce and Soybean Paste. Foods · PMID 40724227 · DOI |
Laboratory study n/a |
Microbes isolated from soy sauce ferments and from thua nao (a fermented soybean food) | Soy sauce fermentation (microbe isolation) Soy sauce ferment |
Most histamine- and tyramine-making strains belonged to Bacillus. Bacillus cereus and the yeast Millerozyma farinosa were identified as key producers of tyramine and histamine during soy sauce fermentation. Histamine and tyramine formation did not rise and fall together under different conditions. No amounts per serving in the abstract (Not applicable) Methods, limits and fundingOutcomes: Which microbes make histamine and tyramine during the ferment Limitations: It identifies the microbes. It does not say how much histamine or tyramine finished soy sauce holds, so it gives no per-spoonful figure. Funding and conflicts: Funded by research bodies in China and Thailand (National Natural Science Foundation of China, a Jiangxi science department, Chiang Mai University). Authors declared no conflicts. Read: abstract |
| s-fda-allergens US FDA: Food Allergies · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text | ||
| s-fda-glutenfree US FDA: Gluten-Free Labeling of Foods · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text | ||
| s-fda-msg US FDA: Questions and Answers on Monosodium glutamate (MSG) · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text | ||
| s-fda-sodium US FDA: Sodium in Your Diet · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text | ||
| s-gbif-glycine-max GBIF Backbone: Glycine max (L.) Merr. (usageKey 5359660) · Source |
Reference database n/a |
Methods, limits and fundingRead: full-text | ||
| s-gbif-triticum-aestivum GBIF Backbone: Triticum aestivum L. (usageKey 7795888) · Source |
Reference database n/a |
Methods, limits and fundingRead: full-text | ||
| s-nccih-soy NCCIH (US National Institutes of Health): Soy: Usefulness and Safety · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text | ||
| s-niddk-ckd NIDDK: Healthy Eating for Adults with Chronic Kidney Disease · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text | ||
| s-usda-fdc-174277 USDA FoodData Central: Soy sauce made from soy and wheat (shoyu) (FDC 174277, SR Legacy, last updated 4/1/2019) · Source |
Reference database n/a |
Methods, limits and fundingRead: full-text | ||
| s-usda-fdc-174278 USDA FoodData Central: Soy sauce made from soy (tamari) (FDC 174278, SR Legacy, last updated 4/1/2019) · Source |
Reference database n/a |
Methods, limits and fundingRead: full-text | ||
| s-who-sodium WHO: Sodium reduction (fact sheet) · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text |
What we do not know yet
- No trial or cohort study of soy sauce alone was found for blood pressure, blood sugar, cholesterol, weight, heart disease or cancer; the results here are about salt or about fermented soy foods as a group.
- No typical histamine, tyramine or glutamate amount per spoonful of soy sauce was found in a source.
- Whether tamari sold in shops is wheat-free was not found in a source, and reduced-sodium, sweet and gluten-free soy sauces were not read in USDA data.
- No source was read on soy sauce and thyroid medicine, on infants or choking, or on soy sauce in pregnancy beyond the general NCCIH soy statement.
- The official 3-MCPD limit documents (JECFA and national agencies) were not read; the figures come from study abstracts.
- Live microbes in finished soy sauce, how long an opened bottle keeps and home-made soy sauce were not researched.
How new research is added
New studies are found by a saved PubMed search and placed in a review queue before the page changes.
Lab markers
What changed in blood or saliva tests during trials. A changed number is not the same as feeling or being healthier, and we give no "normal ranges".
Metabolic 1
Total cholesterol
Lowered in trials
All the cholesterol carried in the blood, including LDL and HDL.
Low certaintyResults and what it means
Why it was measured
A common blood marker in diet trials.
Statistical vs. clinical meaning
A small average fall, not specific to soy sauce.
Safety implication
None specific.
| Study | Result | People | Product |
|---|---|---|---|
| 12 | Total cholesterol -5.0 mg/dL (95% CI -6.60 to -3.39) | 15 randomised trials of fermented soy | Fermented soy products (foods not listed in the abstract) versus controls |
Other 4
Systolic blood pressure (the top number)
Lowered in trials
The pressure in your arteries when the heart beats. A higher resting level raises heart and stroke risk over time.
High certaintyResults and what it means
Why it was measured
It is the usual outcome in salt-reduction trials, and soy sauce is a salty food.
Statistical vs. clinical meaning
An average fall of a few mmHg from eating less salt. A trial of soy sauce itself was not found.
Safety implication
See the sodium and kidney points on the Safety tab.
| Study | Result | People | Product |
|---|---|---|---|
| 4 | Systolic -4.18 mmHg (95% CI -5.18 to -3.18) with a modest salt cut; -5.39 mmHg in people with high blood pressure and -2.42 mmHg in people with normal blood pressure | 34 trials, 3,230 adults | Reduced salt intake (about 4.4 g a day less) for at least 4 weeks; not soy sauce |
Diastolic blood pressure (the bottom number)
Lowered in trials
The pressure in your arteries between heartbeats.
High certaintyResults and what it means
Why it was measured
Reported beside systolic pressure in salt-reduction trials.
Statistical vs. clinical meaning
A smaller average fall than for the top number.
Safety implication
None specific.
| Study | Result | People | Product |
|---|---|---|---|
| 4 | Diastolic -2.06 mmHg (95% CI -2.67 to -1.45); -2.82 mmHg in people with high blood pressure and -1.00 mmHg in people with normal blood pressure | 34 trials, 3,230 adults | Reduced salt intake for at least 4 weeks; not soy sauce |
Fasting blood glucose
Lowered in trials
Blood sugar measured after not eating overnight.
Low certaintyResults and what it means
Why it was measured
It shows how well blood sugar is controlled between meals.
Statistical vs. clinical meaning
A small average fall, not specific to soy sauce.
Safety implication
None specific.
| Study | Result | People | Product |
|---|---|---|---|
| 12 | Fasting glucose -6.39 mg/dL (95% CI -10.38 to -2.40) | 15 randomised trials of fermented soy | Fermented soy products (foods not listed in the abstract) versus controls |
Waist circumference
Lowered in trials
The distance around the waist, a rough measure of belly fat.
Low certaintyResults and what it means
Why it was measured
Waist size is linked to cardiometabolic risk.
Statistical vs. clinical meaning
Small and close to no change at the lower end of the interval.
Safety implication
None specific.
| Study | Result | People | Product |
|---|---|---|---|
| 12 | Waist -1.50 cm (95% CI -2.94 to -0.07); BMI -0.14 kg/m2 (-0.28 to -0.01) | 15 randomised trials of fermented soy | Fermented soy products (foods not listed in the abstract) versus controls |
Safety
What studies and official sources say about side effects, medicines and who should check first. Each point shows what kind of evidence it comes from.
Main points to know 4
- Salt: the main safety point. By USDA data, a tablespoon of soy sauce holds roughly 880 mg (with wheat, 16 g) to 1,000 mg (tamari, 18 g) of sodium, about 38% to 44% of the 2,300 mg US Daily Value. WHO recommends adults take less than 2,000 mg of sodium a day and names soy sauce among condiments that are often high in sodium. Cutting salt lowers blood pressure in trials. A spoonful adds up quickly. Authoritative guidance 29 30 31 24 4
- Soy and wheat are major allergens, and most soy sauce has both. The US FDA lists soybeans and wheat among the nine major food allergens. USDA describes regular soy sauce as made from soy and wheat. Fermentation does not reliably remove allergens: a lab study found soy allergens were broken down but not completely in raw soy sauce, and a 2025 review found one study where a fermented soy food made the allergic response worse. If you are allergic to soy or wheat, ask an allergist before using any soy sauce. Authoritative guidance 21 29 11 6
- Wheat, gluten and celiac disease: read the label, including for tamari. USDA lists regular soy sauce as made from soy and wheat, and a StatPearls guide names soy sauce among foods that commonly contain gluten. A 2026 lab study of 15 soy sauces found gluten below the limit of the standard ELISA test, yet it still detected small amounts of celiac-active peptides (0.2 to 0.5 mg/kg). USDA lists tamari as made from soy, but we did not read a source on the wheat content of tamari sold in shops. FDA says "gluten-free" is a voluntary label claim and has a rule for fermented and hydrolyzed foods. Laboratory analysis 29 30 1 17 22
- MAOI antidepressants and tyramine. NCCIH reports that high-tyramine soy products such as tofu and soy sauce have been linked with dangerously high blood pressure in people taking MAOIs. A 1999 lab study found high tyramine in one of the soy sauces it tested and advised avoiding soy sauce on MAOIs. A 2018 review says modern foods contain much less tyramine and the risk has been overstated, but that people differ. If you take an MAOI, ask your prescriber or pharmacist before using soy sauce. Authoritative guidance 27 16 2
Side effects 3
| Effect | How often | Severity and recovery | Evidence |
|---|---|---|---|
| Allergic reactions to soy or wheat, from itching and hives to anaphylaxis FDA lists soybeans and wheat among the major allergens. The sources read do not give a rate of reactions to soy sauce itself. | No frequency for soy sauce was found. | can be severe (anaphylaxis) Not described in the sources read. | Authoritative guidance 21 11 6 |
| Headache, flushing and similar short-term symptoms in people sensitive to histamine, tyramine or glutamate The amine review is about fermented foods in general. A 2025 lab study found microbes in soy sauce ferments that make histamine and tyramine, but we found no typical amount per spoonful. | No frequency for soy sauce was found. FDA says reports of symptoms after MSG could not be confirmed to be caused by MSG, and a review says reactions can occur at amine levels far below suggested toxic doses depending on the person. | mild to moderate in the sources read FASEB (via FDA) describes the MSG-related symptoms as short-term and transient. | Narrative review 14 23 20 |
| Raised blood pressure from the salt it contains This is a salt effect rather than something special to soy sauce. | Not given for soy sauce. | depends on how much salt a person eats overall In trials, blood pressure fell when salt was cut. | Meta-analysis 4 31 |
Liver
No liver injury from soy sauce eaten as a seasoning was found in the sources read. A liver-safety source (such as LiverTox) was not searched.
How often. No frequency was found.
Monitoring. No agency monitoring advice was found.
This is a safety connection. It is not evidence that Soy Sauce and Tamari supports liver health.
Medicines and supplements 2
| With | Why it matters | Importance | Evidence | What to do |
|---|---|---|---|---|
| MAOI antidepressants (monoamine oxidase inhibitors) prescription | Tyramine in some fermented soy products can raise blood pressure when an MAOI is blocking its breakdown. A 1999 lab analysis found high tyramine in one soy sauce. A 2023 lab study also found that soy sauce blocks MAO enzymes in the test tube, which has not been shown in people. | NCCIH reports dangerously high blood pressure with high-tyramine soy products such as tofu and soy sauce and MAOIs. The 1999 authors advised avoiding soy sauce. A 2018 review says the risk from modern foods has been overstated. Product and storage differ. | Case reports and lab analysis Low certainty 27 16 2 5 | Ask your prescriber or pharmacist before using soy sauce on an MAOI, and tell them which sauce you use. |
| Blood pressure medicines and any advice to limit sodium prescription | Not studied for soy sauce. Soy sauce is a concentrated source of sodium, and WHO says high sodium raises blood pressure. | No source read tested soy sauce against any blood pressure medicine. If your care team has set a sodium limit, soy sauce counts toward it. | Authoritative guidance Not enough evidence 31 28 | Follow the sodium limit your doctor or dietitian has given you, and ask them how a seasoning like soy sauce fits. |
Who should check first 5
| Situation | Advice | Evidence |
|---|---|---|
| Known or suspected soy allergy or wheat allergy | Avoid soy sauce unless an allergist has told you a specific product is safe. Read the label. For trouble breathing or swelling of the face, lips or throat, call 911 or your local emergency number. | Authoritative guidance 21 11 |
| Celiac disease | Regular soy sauce is made with wheat. Look for a gluten-free claim and ask your care team, because a low result on the standard gluten test did not rule out celiac-active peptides in a 2026 lab study. Wheat allergy is a different condition from celiac disease. | Laboratory analysis 29 17 22 23 |
| Taking an MAOI antidepressant | Ask your prescriber or pharmacist about soy sauce before using it. | Authoritative guidance 27 16 |
| Chronic kidney disease, high blood pressure, or a doctor-set sodium limit | NIDDK lists soy sauce among high-sodium sauces and says many people with chronic kidney disease need a sodium limit lower than 2,300 mg a day, set by their care team. Ask your care team how much room soy sauce leaves. | Authoritative guidance 28 31 |
| Pregnancy, breastfeeding and children | No official statement about soy sauce itself was read. NCCIH says soy in amounts greater than those commonly found in foods may be unsafe in pregnancy; it does not single out soy sauce. WHO says sodium advice for children aged 2 to 15 should be adjusted downward from the adult figure. Ask a midwife, doctor or dietitian. | Authoritative guidance 27 31 |
Overdose, product quality and regulators
Summary. No toxicity from soy sauce eaten as a seasoning was found in the sources read. The safety points are salt, allergy, wheat and gluten, the MAOI question, amines and a processing contaminant (3-MCPD) in some products.
Animal. A 2015 review says 3-MCPD has been reported to be carcinogenic, to harm the kidney and to harm reproduction in laboratory animals. This is animal work on the contaminant, not on soy sauce.
High dose or long term signals. WHO links diets high in sodium to raised blood pressure and cardiovascular disease. For MSG, FASEB (via FDA) found short-term mild symptoms in some sensitive people who consume 3 grams or more of MSG without food; that is added MSG, not soy sauce.
Overdose response. Not found.
Genotoxicity. 3-MCPD is classed as a possible carcinogen according to a 2015 review; see Contamination.
3-MCPD is a contaminant that can form when soy sauce is made by acid hydrolysis of vegetable protein (acid-HVP). Surveys found a wide range between products, from none detected to levels above national limits, and risk assessments of average eaters found low concern.
3-MCPD in soy sauce (what it is). A 2015 review says soy sauce comes as fermented, acid-HVP or mixed types, and that 3-MCPD is a heat-formed contaminant first found in 1978 as a by-product of acid-HVP soy sauce. It has been reported as carcinogenic, kidney-toxic and reproductively toxic in laboratory animals and is classed as a possible carcinogen. National and international limits exist. 8
3-MCPD levels in UK shops (about 2000). In 40 products, 21 (52%) had no detectable 3-MCPD, and 9 (23%) had more than 1 mg/kg, the highest being 30.5 mg/kg. The survey was prompted by reports of up to 124 mg/kg in some European products. 10
3-MCPD levels and intake in Korea (2020). In 31 soy sauces the mean was 11.62 micrograms per kg and 7 (23%) were above Korea's limit of 20 micrograms per kg. Estimated intake was 0.03 to 0.11% of the provisional maximum tolerable daily intake for average consumers, which the authors called low concern. 7
3-MCPD and intake risk in Malaysia (2020). Across 43 foods, levels ranged up to 0.1223 mg/kg, with the highest in chicken seasoning cubes. Modelled intakes of 3-MCPD and 1,3-DCP were below the 4 micrograms per kg body weight a day limit the authors attribute to JECFA in 2016, and the authors concluded soy sauce consumption there does not present a health risk. 18
Histamine and tyramine from microbes in the ferment. A 2025 lab study found that Bacillus and a yeast in soy sauce ferments make histamine and tyramine. No per-spoonful amount was found. 20 14
| Body | Action | Date |
|---|---|---|
| US FDA (United States) | Food Allergies: soybeans and wheat are two of nine major food allergens; foods containing them must name the source on the label. source | 2026-03-11 |
| NCCIH (US National Institutes of Health) (United States) | Soy: Usefulness and Safety. High-tyramine soy products such as tofu and soy sauce and MAOIs have been reported to cause dangerously high blood pressure; soy above food amounts may be unsafe in pregnancy. source | 2025-04 |
| World Health Organization (International) | Sodium reduction: adults under 2000 mg sodium (under 5 g salt) a day; condiments such as soy and fish sauce are often high in sodium. source | 2026-05-11 |
| US FDA (United States) | Sodium in Your Diet: Daily Value less than 2,300 mg; 20% DV or more per serving is high. source | 2024-03-05 |
| US FDA (United States) | Gluten-free labeling is voluntary; a 2020 final rule covers fermented or hydrolyzed foods. source | 2026-03-17 |
| US FDA (United States) | Questions and Answers on MSG: added MSG is generally recognized as safe; people who report MSG sensitivity have not been consistently shown to react in placebo studies; celiac patients may react to wheat in soy sauce but not to glutamate. source | 2026-07-17 |
| NIDDK (US National Institutes of Health) (United States) | Healthy eating for adults with chronic kidney disease: soy sauce is among high-sodium sauces; many people with CKD need a lower sodium limit set by their care team. source | 2025-01 |
When to get medical help
- Trouble breathing, wheezing, swelling of the lips, face, tongue or throat, widespread hives, repeated vomiting, dizziness or collapse after using soy sauce (possible anaphylaxis): use epinephrine if prescribed, then call 911 or your local emergency number
- Signs of dangerously high blood pressure after eating soy sauce while taking an MAOI (such as a severe sudden headache, a pounding heartbeat, chest pain or confusion): seek urgent medical help
Stop using the product and contact a clinician or emergency service. In the US, Poison Control is 1-800-222-1222.
General information only, not medical advice. Ask a clinician or pharmacist before use, especially with medicines, in pregnancy or with a health condition. See the Natural Remedy Safety guide.
Frequently asked questions
What is the difference between soy sauce and tamari?
Both are fermented soy seasonings. USDA lists regular soy sauce as made from soy and wheat (shoyu) and tamari as made from soy. USDA per 100 g: shoyu 53 kcal and 8.14 g protein, tamari 60 kcal and 10.5 g protein; sodium is similar (5,490 and 5,590 mg). Products on shelves can differ, so check the label.
How salty is soy sauce?
Does soy sauce raise blood pressure?
Is tamari gluten-free, and is soy sauce safe for celiac disease?
Not automatically. USDA lists regular soy sauce as made with wheat and tamari as made from soy, but we did not read a source on wheat in shop tamari, so check the label. A 2026 lab study found gluten below the test limit in 15 soy sauces but still found small amounts of celiac-active peptides. Ask your care team.
Is soy sauce safe if I am allergic to soy or wheat?
Ask an allergist. Soybeans and wheat are major food allergens, and fermentation does not reliably remove them: soy allergens were not completely broken down in raw soy sauce in a lab study, and a 2025 review found one study where a fermented soy food worsened the reaction. A low gluten test does not prove safety for wheat allergy. For trouble breathing or throat swelling, call 911.
Can I use soy sauce if I take an MAOI antidepressant?
Does soy sauce contain histamine, and is it a problem for histamine sensitivity?
Does soy sauce contain MSG?
FDA says free glutamate occurs naturally with sodium in soy extracts and other protein-breakdown ingredients, and that it is chemically the same as the glutamate in added MSG. FDA considers added MSG generally recognized as safe; people who report sensitivity have not been consistently shown to react in placebo studies. We found no measured glutamate value for soy sauce. Glutamate is unrelated to gluten.
What is 3-MCPD in soy sauce?
A contaminant that forms when vegetable protein is broken down with acid and heat. A 2015 review says it has been reported as carcinogenic in lab animals. A UK survey found none in 52% of 40 products but over 1 mg/kg in 23%; Korean and Malaysian studies estimated low intakes for average eaters. Levels depend on the product.
Is soy sauce a probiotic food?
We found no source showing live microbes in finished soy sauce. ISAPP defines fermented foods as made through desired microbial growth and says they are distinct from probiotics.
Does fermented soy help blood sugar or cholesterol?
What about kidney disease, pregnancy and children?
NIDDK lists soy sauce among high-sodium sauces and says many people with chronic kidney disease need a lower sodium limit set by their care team. No official statement about soy sauce in pregnancy was read; NCCIH says soy above food amounts may be unsafe. WHO says children aged 2 to 15 need the adult sodium figure adjusted downward. Ask your care team.
Explore by health goal
Blood Pressure SupportHeart HealthBlood Sugar BalanceCholesterol Balance
Editorial transparency
- Written by
- AlternativeMed editorial team. Research compiled with AI assistance, then checked against the sources listed.
- Medical review
- None. This page has not been reviewed by a physician or pharmacist.
- First published
- 2026-10-26
- Last substantive update
- 2026-10-26
- How we research
- We started from our existing soy sauce summary, re-checked nutrition against USDA FoodData Central, read the health agency pages (NCCIH, FDA, WHO, NIDDK) and re-read PubMed abstracts for the reviews, surveys and lab studies cited. Only abstracts were read for studies. Items we could not verify are flagged in the research gaps.
- How we rate evidence
- See "How we rate evidence" in the Evidence tab.
- Independence
- No product is promoted on this page. No affiliate links are shown. Interests are noted where studies are used: some members of the ISAPP panel on fermented foods reported consulting work for food companies, and two authors of the sodium reformulation study belong to salt-reduction campaign groups.
Sources 31
Each source was opened and checked. Where we read only the abstract, it says so. The small numbers in the text point here.
- Akhondi H, Ross AB. Gluten-Associated Medical Problems.. . 2025. PMID 30860740. (abstract)
- Gillman PK. A reassessment of the safety profile of monoamine oxidase inhibitors: elucidating tired old tyramine myths.. J Neural Transm (Vienna). 2018. PMID 30255284. DOI 10.1007/s00702-018-1932-y. (abstract)
- Harun Z, Shahar S, Haron H, et al.. Reformulation of soy sauce to reduce sodium content and assessment of manufacturer readiness, consumer acceptance, and shelf life.. Sci Rep. 2025. PMID 41315354. DOI 10.1038/s41598-025-26750-2. (abstract)
- He FJ, Li J, Macgregor GA. Effect of longer-term modest salt reduction on blood pressure.. Cochrane Database Syst Rev. 2013. PMID 23633321. DOI 10.1002/14651858.CD004937.pub2. (abstract)
- Herraiz T. β-Carboline Alkaloids in Soy Sauce and Inhibition of Monoamine Oxidase (MAO).. Molecules. 2023. PMID 36985694. DOI 10.3390/molecules28062723. (abstract)
- Hyseni B, Papadimitriou K, Issa A, et al.. The role of fermented foods in managing food allergies in children and adults: a systematic review.. Front Nutr. 2025. PMID 41561179. DOI 10.3389/fnut.2025.1689636. (abstract)
- Jang Y, Koh E. Assessment of estimated daily intake of 3-monochloropropane-1,2-diol from soy sauce in Korea.. Food Sci Biotechnol. 2020. PMID 33282433. DOI 10.1007/s10068-020-00832-5. (abstract)
- Lee BQ, Khor SM. 3-Chloropropane-1,2-diol (3-MCPD) in Soy Sauce: A Review on the Formation, Reduction, and Detection of This Potential Carcinogen.. Compr Rev Food Sci Food Saf. 2015. PMID 33401813. DOI 10.1111/1541-4337.12120. (abstract)
- Li W, Wei X, Zhang J, et al.. Soy Foods Consumption and Multiple Health Outcomes: An Umbrella Review of Meta-Analyses.. Mol Nutr Food Res. 2026. PMID 41327897. DOI 10.1002/mnfr.70255. (abstract)
- Macarthur R, Crews C, Davies A, et al.. 3-monochloropropane-1,2-diol (3-MCPD) in soy sauces and similar products available from retail outlets in the UK.. Food Addit Contam. 2000. PMID 11271703. DOI 10.1080/026520300750038072. (abstract)
- Magishi N, Yuikawa N, Kobayashi M, et al.. Degradation and removal of soybean allergen in Japanese soy sauce.. Mol Med Rep. 2017. PMID 28656270. DOI 10.3892/mmr.2017.6815. (abstract)
- Maleki Sedgi F, Mozaffari N, Pashaei MR, et al.. Effect of fermented soybean on metabolic outcomes, anthropometric indices, and body composition: a systematic review and meta-analysis of clinical trials.. Food Funct. 2025. PMID 39763426. DOI 10.1039/d4fo02668c. (abstract)
- Marco ML, Sanders ME, Gänzle M, et al.. The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on fermented foods.. Nat Rev Gastroenterol Hepatol. 2021. PMID 33398112. DOI 10.1038/s41575-020-00390-5. (abstract)
- Saha Turna N, Chung R, McIntyre L. A review of biogenic amines in fermented foods: Occurrence and health effects.. Heliyon. 2024. PMID 38304783. DOI 10.1016/j.heliyon.2024.e24501. (abstract)
- Shahar S, You YX, Zainuddin NS, et al.. Sodium content in sauces-a major contributor of sodium intake in Malaysia: a cross-sectional survey.. BMJ Open. 2019. PMID 31133578. DOI 10.1136/bmjopen-2018-025068. (abstract)
- Shulman KI, Walker SE. Refining the MAOI diet: tyramine content of pizzas and soy products.. J Clin Psychiatry. 1999. PMID 10192596. (abstract)
- Tissen E, Dakwar L, Geisslitz S, et al.. Proteomics Analysis of Celiac Disease-Active Peptides in Food Products with Partially Hydrolyzed Gluten.. J Agric Food Chem. 2026. PMID 41525254. DOI 10.1021/acs.jafc.5c13719. (abstract)
- Wong SF, Lee BQ, Low KH, et al.. Estimation of the dietary intake and risk assessment of food carcinogens (3-MCPD and 1,3-DCP) in soy sauces by Monte Carlo simulation.. Food Chem. 2020. PMID 31869642. DOI 10.1016/j.foodchem.2019.126033. (abstract)
- Zanfirescu A, Ungurianu A, Tsatsakis AM, et al.. A review of the alleged health hazards of monosodium glutamate.. Compr Rev Food Sci Food Saf. 2019. PMID 31920467. DOI 10.1111/1541-4337.12448. (abstract)
- Zhang X, Li S, Liu H, et al.. Isolation and Characterizations of Histamine- and Tyramine-Producing Strains Isolated from Fermented Soybean Food: Soy Sauce and Soybean Paste.. Foods. 2025. PMID 40724227. DOI 10.3390/foods14142407. (abstract)
- . US FDA: Food Allergies. . . (full-text)
- . US FDA: Gluten-Free Labeling of Foods. . . (full-text)
- . US FDA: Questions and Answers on Monosodium glutamate (MSG). . . (full-text)
- . US FDA: Sodium in Your Diet. . . (full-text)
- . GBIF Backbone: Glycine max (L.) Merr. (usageKey 5359660). . . (full-text)
- . GBIF Backbone: Triticum aestivum L. (usageKey 7795888). . . (full-text)
- . NCCIH (US National Institutes of Health): Soy: Usefulness and Safety. . . (full-text)
- . NIDDK: Healthy Eating for Adults with Chronic Kidney Disease. . . (full-text)
- . USDA FoodData Central: Soy sauce made from soy and wheat (shoyu) (FDC 174277, SR Legacy, last updated 4/1/2019). . . (full-text)
- . USDA FoodData Central: Soy sauce made from soy (tamari) (FDC 174278, SR Legacy, last updated 4/1/2019). . . (full-text)
- . WHO: Sodium reduction (fact sheet). . . (full-text)
Where to buy
Check the label first. Whatever you buy, look for these:
- Live and active cultures on the label, if that is what you want
- Refrigerated or shelf-stable, since shelf-stable versions may be heat treated
- Added sugar and sodium
- A best-by date
Talk to a pharmacist or doctor before you start any supplement, especially if you take medicines. See the Safety tab for interactions.
Support our free guides: as an Amazon Associate we earn from qualifying purchases. Full disclosure.
