A bowl of plain yogurt.

Yogurt

Lactic-fermented milk · also called Yoghurt, plain yogurt, Greek yogurt (strained)

Yogurt is milk fermented by bacterial cultures. The best-supported finding is that people who digest lactose poorly tolerate it better than milk. Large studies link yogurt with lower diabetes risk, which cannot prove cause, and cholesterol trials are small and use probiotic yogurt. The main cautions are milk allergy, unpasteurised yogurt in pregnancy and added sugar in flavoured types.

General information, not medical advice. Last substantive update October 26, 2026 · Not medically reviewed. A named clinician has not signed off on this page. How this page is made

About Yogurt

Yogurt is milk fermented by bacterial cultures. It is a source of protein and calcium. The firmest finding is better lactose tolerance than with milk. Other findings are observational or from small trials. It is a food, not a proven remedy. The clearest cautions are milk allergy, unpasteurised yogurt in pregnancy and added sugar.

What it is

Yogurt is milk fermented by cultures of bacteria. Greek yogurt is strained to make it thicker, and flavoured yogurts may have sugar added. A fermented food is not automatically a probiotic: the expert group ISAPP defines fermented foods as foods made through desired microbial growth and enzymatic conversions of food components, and says a probiotic must be shown to give a health benefit.

We read nothing on how yogurt began or how shop yogurt is made, so this page does not cover its history.

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What is in it (USDA data)

Plain low-fat yogurt, per 100 g (USDA FDC 170886): 63 kcal, 5.25 g protein, 1.55 g fat, 7.04 g sugars (all natural milk sugar), 183 mg calcium, 234 mg potassium, 70 mg sodium and 0.56 micrograms vitamin B-12. One cup (245 g) works out at about 154 kcal, 12.9 g protein, 17 g sugars and 448 mg calcium.

Plain nonfat Greek yogurt, per 100 g (USDA FDC 170894): 59 kcal, 10.19 g protein, 0.39 g fat, 3.24 g sugars, 110 mg calcium and 36 mg sodium. It has about twice the protein of the plain low-fat yogurt and less calcium and sugar.

These are two plain, unsweetened items. Flavoured yogurts can carry added sugar, and brands differ. Read the Nutrition Facts label. These numbers describe the food and are not advice on how much to eat.

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What the research shows

Lactose: in a 15-person test, plain yogurt gave off about a third of the breath hydrogen that milk did (76 versus 224 ppm x h), and flatulence was 54% to 71% lower. NIDDK suggests trying yogurt if you have lactose intolerance.

Long-term health: cohort studies link more yogurt with lower type 2 diabetes risk. A pooled analysis of 8 cohorts (235,676 people) found no significant link between highest versus lowest yogurt intake and death from any cause (HR 0.93, 0.85 to 1.01); the paper's title is stronger than its main result. A 2021 review of 108 studies reports consistent associations with several outcomes, but its authors argue for yogurt in dietary guidelines, and most of the links are observational.

Cholesterol: 7 small trials of probiotic yogurt found LDL lower by about 10.6 mg/dL. A 2025 review of 68 studies on fermented dairy found most trials showed no lipid change, and rated the overall evidence neither convincing nor sufficient.

Inflammation markers and gut bacteria: one small trial found IL-6 lower with Greek yogurt after training, while another found no change in IL-6 with a dairy mix. We found no trial of ordinary yogurt for a gut condition.

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Food versus supplements

The lactose and long-term findings are for yogurt eaten as food. The cholesterol trials used yogurt with added probiotic strains, which not every yogurt contains. The inflammation result is from Greek yogurt after workouts. Probiotic supplements are a different product, and a fermented food is not automatically a probiotic.

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At a glance

Traditional uses history, not proof

Eaten as an everyday food in many places
Long use as food is not proof that it treats any condition

Studied for research

Lactose digestion, moderate certainty (a small trial and a review)
Type 2 diabetes and other long-term health links, low certainty (observational)
Death from any cause, very low certainty (main result not significant)
Cholesterol, low certainty (probiotic yogurt only)
Inflammation markers, very low certainty (two small trials)
Gut bacteria and gut health, not enough evidence

Main compounds

Milk protein
Lactose (milk sugar)
Calcium
Vitamin B-12 and riboflavin
Live starter cultures (vary by product)

Common forms

Plain low-fat yogurt (USDA values read)
Plain nonfat Greek yogurt (USDA values read)
Yogurt with added probiotic strains (used in the cholesterol trials)
Flavoured and sweetened yogurt, drinkable yogurt and probiotic supplements are different products and are not covered

Research links: 2003 trial: yogurt, kefir and lactose digestion · 2020 review: probiotic yogurt and cholesterol (7 trials) · 2021 review: yogurt, fermented milk and health · Research Library · Genes & Biomarkers Library

What it is and its history

Accepted scientific name: Not a species. Yogurt is a food made from milk fermented by bacterial cultures.
Common names: Yogurt (English (US)); Yoghurt (English (UK)); Plain yogurt (English); Greek yogurt (strained) (English)
Family or group: Fermented dairy foods (lactic-fermented milk)
Native range: Not verified from a source read.
Harvest and processing: Yogurt is milk fermented by cultures. The USDA lists plain low-fat yogurt and plain nonfat Greek yogurt as separate foods; the Greek item is strained, which makes it thicker with more protein per 100 g. How shop yogurt is made, which cultures it contains and whether they are still alive when you eat it were not read from a source.
Look-alikes and adulterants: Name: Kefir; Note: Another fermented milk with its own page; the lactose trial read tested both.; Name: Skyr and quark; Note: Thick strained fermented dairy foods with their own page.; Name: Lassi and ayran; Note: Drinks made from yogurt, with their own page.; Name: Flavoured or sweetened yogurt; Note: May contain added sugar; not the plain yogurt in most of the studies.; Name: Yogurt with added probiotic strains; Note: The kind used in the cholesterol trials; not the same as every yogurt.

Photographs

Yogurt close-up — A bowl of plain yogurt.

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
Milk protein	protein	USDA per 100 g: plain low-fat yogurt 5.25 g; plain nonfat Greek yogurt 10.19 g	A source of protein. It is also the source of the milk allergen. ^{19 20 15}	Human data
Lactose	sugar	USDA lists 7.04 g of sugars per 100 g for plain low-fat yogurt (all sugars; the split is not given in the data read)	The natural milk sugar. People who digest it poorly had much less breath hydrogen after yogurt than after milk. ^{19 3 17}	Human data
Calcium	mineral	USDA per 100 g: plain low-fat yogurt 183 mg; plain nonfat Greek yogurt 110 mg	A nutrient in the food. How well it is absorbed from yogurt was not read. ^{19 20}	Human data
Vitamin B-12 and riboflavin (B2)	vitamin	USDA per 100 g, plain low-fat yogurt: B-12 0.56 micrograms; riboflavin 0.214 mg	Nutrients in the food. No study read tested the effect of yogurt on B vitamin levels in people. ¹⁹	Human data
Live starter cultures	microorganisms	Not found. Counts vary by product and were not read from a source.	ISAPP says a fermented food is not automatically a probiotic; a probiotic must be shown to give a benefit. ^{5 4}	Human data

Mechanisms, receptors and pathways

Target or pathway	Gene or receptor	What was found	Level
Lactose breakdown	Not specified in the sources read	In a small trial, plain yogurt gave off much less breath hydrogen than milk with the same lactose, meaning less undigested lactose reached the gut bacteria. The abstract does not say why. The usual explanation is that yogurt bacteria help break down lactose; this was not tested in the sources read. ³	Human data
Tyramine formation during fermentation	Not specified in the abstract	A lab study found tyramine rose during fermentation of lab-made sheep milk yogurts. Not shown in shop yogurt or in people. ⁹	Lab

Absorption, metabolism and elimination

Absorption: Not found for yogurt nutrients in people.
Distribution: Not found.
Metabolism: Lactose digestion is reflected by breath hydrogen in the trial read.
Elimination: Not found.
Bioavailability: Not established for yogurt calcium or B vitamins in the sources read.

Isolated compounds versus whole extracts

The lactose and long-term findings are for yogurt eaten as food. The cholesterol trials used yogurt with added probiotic strains, which not every yogurt contains. The Greek yogurt trial used strained yogurt after workouts, and the dairy mix trial combined milk, skyr and cheddar. Probiotic supplements are different products and are not covered.

Nutritional composition

Nutrition from USDA FoodData Central (SR Legacy, April 2018 release), read 2026-10-26 from a saved copy of the data in our files because the public API key was rate-limited when checked. Plain low-fat yogurt (FDC 170886), per 100 g: 63 kcal, 5.25 g protein, 1.55 g fat (1.0 g saturated), 7.04 g carbohydrate (all of it sugars), no fibre, 183 mg calcium, 144 mg phosphorus, 234 mg potassium, 70 mg sodium, 17 mg magnesium, 0.89 mg zinc, 3.3 micrograms selenium, 0.214 mg riboflavin, 0.56 micrograms vitamin B-12, 0.354 micrograms vitamin D and 6 mg cholesterol. One cup (8 fl oz, 245 g, a USDA household portion), worked out from the per-100 g values, is about 154 kcal, 12.9 g protein, 3.8 g fat, 17 g sugars, 448 mg calcium, 172 mg sodium and 573 mg potassium. Plain nonfat Greek yogurt (FDC 170894), per 100 g: 59 kcal, 10.19 g protein, 0.39 g fat, 3.24 g sugars, 110 mg calcium, 36 mg sodium; a USDA container of 170 g gives about 100 kcal, 17.3 g protein, 5.5 g sugars and 187 mg calcium. These are two plain unsweetened items. Flavoured, whole-milk and sweetened yogurts differ, and brands vary, so read the label. These numbers describe the food and are not advice on how much to eat.

5benefits and uses looked at

21studies and sources checked

Moderate certaintybest evidence rating found

7lab markers tracked in trials

1 moderate certainty2 low certainty1 very low certainty1 not enough evidence

What was looked at

The 5 benefits and uses checked for Yogurt, each with how strong the evidence is. Tap one to open it.

Lactose digestion and toleranceModerate certainty
Long-term health links (diabetes, death rates, weight, bone, heart)Low certainty
Cholesterol (yogurt with added probiotic strains)Low certainty
Inflammation markers in the blood (Greek yogurt and mixed dairy diets)Very low certainty
Gut bacteria and general gut healthNot enough evidence

Lab markers tracked in the studies

Breath hydrogen (a sign of undigested lactose)LDL cholesterolTotal cholesterolDeath from any causeInterleukin-6 (IL-6)Tumour necrosis factor alpha (TNF-alpha)C-reactive protein (CRP)

What is Yogurt good for?

The main studied uses and how strong the human evidence is for each. Most of the long-term findings are observational, and the cholesterol trials used yogurt with added probiotic strains.

Lactose digestion and toleranceModerate certaintyIn 15 adults who digest lactose poorly, plain yogurt gave off much less breath hydrogen than the same lactose in milk (76 versus 224 ppm x h). A review of 108 studies calls the link between yogurt and lactose digestion causal. One small trial of single meals. Yogurt still has lactose, and milk allergy is a different problem. Type 2 diabetes, death rates and other long-term links (observational)Low certaintyYogurt was linked with a lower risk of type 2 diabetes (RR 0.86 at 80 g a day). In 8 cohorts, the highest versus lowest yogurt intake was not significantly linked to death from any cause (HR 0.93, 0.85 to 1.01); only a 200 g a day or more subgroup was (HR 0.88). A link, not proof of cause. One author has dairy industry grants. Cholesterol (probiotic yogurt)Low certaintyIn 7 small trials (274 people), yogurt with added probiotic strains lowered total cholesterol by 8.73 mg/dL and LDL by 10.611 mg/dL. HDL and triglycerides did not change. A wider review of fermented dairy called the evidence neither convincing nor sufficient. Not shown for plain yogurt. Inflammation markers (Greek yogurt, mixed dairy)Very low certaintyIn 30 young men, IL-6 was lower after 12 weeks of Greek yogurt than after a carbohydrate pudding. In a 6-week dairy mix trial the main marker (IL-6) did not change. Blood markers, not health results. Dairy industry ties declared. Gut bacteria and gut healthNot enough evidenceISAPP says a fermented food is not automatically a probiotic. We found no trial of ordinary yogurt for a gut condition in the sources read. A gap in the evidence, not proof of no effect.

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.

Lactose digestion and tolerance

Moderate certainty

In a small trial of 15 adults who digest lactose poorly, plain yogurt gave off much less breath hydrogen (a sign of undigested lactose) than the same amount of lactose in milk. A review of 108 studies says yogurt and lactose digestion are causally linked. Yogurt still contains lactose, so this is about tolerance, not a lactose-free food.

3 studiesPlain and flavoured yogurt in the trial, with a set 20 g lactose port…

Studies, doses and limits

What the trials found

A 15-person randomised test (randomized block design) gave people 20 g of lactose as milk, plain or raspberry yogurt, or plain or raspberry kefir. Breath hydrogen was 224 ppm x h after milk and 76 after plain yogurt, and 76 after flavoured yogurt. Yogurts and kefirs cut perceived flatulence by 54% to 71% compared with milk, and abdominal pain and diarrhoea were negligible. The 2021 systematic review of 108 studies concludes a causal relationship between yogurt and lactose digestion and tolerance. NIDDK suggests trying yogurt, which some people find easier to tolerate than other milk products.

Results

A real, consistent effect on lactose digestion in people who digest lactose poorly. It is the best-supported finding for yogurt.

Effect sizes as reported

Breath hydrogen area under the curve: milk 224 (plus or minus 39), plain yogurt 76 (plus or minus 14, P below .001), flavoured yogurt 76 (P = .005), plain kefir 87, flavoured kefir 156. Flatulence 54% to 71% lower than milk.

Why this rating

Moderate. One small randomised test with a clear difference, a government health page that suggests yogurt, and a review whose authors call it causal. The review is qualitative and its authors argue for yogurt in dietary guidelines, and the trial is only 15 people tested with single meals.

Form and dose studied

Plain and flavoured yogurt in the trial, with a set 20 g lactose portion per test. Not a statement about how much to eat.

Who was studied

Healthy adults who digest lactose poorly.

Limits

Single-meal tests in 15 people. It does not apply to milk allergy, which is a different problem. Different brands and cultures were not compared.

Why researchers looked

Yogurt still contains lactose, but many people with lactose intolerance find it easier to handle than milk.

Traditional use

Yogurt is eaten as a food in many places. Long use as food is not proof that it treats any condition.

Proposed mechanism Hypothesis

Not tested in the studies read. The usual explanation is that the live bacteria in yogurt help break lactose down, but the abstracts read do not test that.

A proposed mechanism does not show that the effect happens in people.

Milk allergy is not the same as lactose intolerance and yogurt is not safe for it. See the Safety tab.

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Long-term health links (diabetes, death rates, weight, bone, heart)

Low certainty

People who eat more yogurt tend to have a lower risk of type 2 diabetes in large studies that follow people over time. For death from any cause, the main result was not significant. These studies show a link, not that yogurt causes it.

3 studiesYogurt as people reported eating it. Plain versus sweetened yogurt wa…

Studies, doses and limits

What the trials found

A 2018 update of cohort studies found yogurt linked to a lower risk of type 2 diabetes (RR 0.86 at 80 g a day, 95% CI 0.83 to 0.90). A 2020 pooled analysis of 8 cohorts (235,676 people, 14,831 deaths) found that the highest versus lowest yogurt intake was not significantly linked to death from any cause (HR 0.93, 0.85 to 1.01), cardiovascular death or cancer death. In a subgroup at 200 g a day or more, the links were significant (any cause HR 0.88, 0.80 to 0.96). The 2021 review also reports consistent associations with weight maintenance, bone and heart health, and lower risk of breast and colorectal cancer, and says dairy in general, fermented or not, is linked with prostate cancer.

Results

A modest, mostly favourable pattern in observational studies. The main death-rate result was not significant. None of this shows that adding yogurt to a diet prevents disease.

Effect sizes as reported

Type 2 diabetes RR 0.86 (0.83 to 0.90) at 80 g/day. Any-cause death HR 0.93 (0.85 to 1.01) highest vs lowest; HR 0.88 (0.80 to 0.96) at 200 g/day or more. Cardiovascular death HR 0.92 (0.81 to 1.03) highest vs lowest; HR 0.87 (0.77 to 0.99) at 200 g/day or more.

Why this rating

Low. All observational, so it cannot show cause, and people who eat yogurt may differ in other habits. The paper titled 'Yogurt Intake Reduces Mortality' found a non-significant main result. One author of the diabetes update has received dairy industry grants, and the review's authors argue for yogurt in guidelines.

Form and dose studied

Yogurt as people reported eating it. Plain versus sweetened yogurt was not separated in the abstracts read.

Who was studied

Adults in cohort studies, mostly Western countries (not stated in the abstracts).

Limits

Association only. Different studies measured yogurt differently. Weight, bone, heart and cancer links come from a review that gives no pooled numbers in its abstract.

Why researchers looked

Large health studies ask people what they eat and follow them for years, and yogurt is one of the foods that has been tracked.

Traditional use

Yogurt is eaten as a food in many places. Long use as food is not proof that it treats any condition.

Proposed mechanism Hypothesis

Not established. The 2021 review argues that yogurt may give benefits beyond milk, but the abstract does not test how.

A proposed mechanism does not show that the effect happens in people.

None specific beyond the general yogurt cautions on the Safety tab.

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Cholesterol (yogurt with added probiotic strains)

Low certainty

A pooled analysis of 7 small trials found that yogurt with added probiotic strains lowered total and LDL ('bad') cholesterol by a small amount in people with mild to moderate high cholesterol. A wider review of fermented dairy called the evidence neither convincing nor sufficient.

2 studiesYogurt with added probiotic strains. The abstracts read give no strai…

Studies, doses and limits

What the trials found

The 2020 meta-analysis pooled 7 trials (274 people) of probiotic yogurt. Total cholesterol fell by 8.73 mg/dL and LDL by 10.611 mg/dL, with no significant change in HDL or triglycerides. The 2025 systematic review of 68 studies on fermented dairy in healthy adults found that most trials reported no significant lipid changes and that a few showed modest falls, particularly with yogurt and kefir. It rated the evidence neither convincing nor sufficient.

Results

A small possible effect for probiotic yogurt in a few small trials. Ordinary yogurt was not shown to lower cholesterol.

Effect sizes as reported

Total cholesterol -8.73 mg/dL (95% CI -15.98 to -1.48); LDL -10.611 mg/dL (-16.529 to -4.693); HDL and triglycerides no significant change.

Why this rating

Low. Small, short trials of a specific kind of yogurt (with added probiotic strains), and a broader review that found the overall evidence not convincing.

Form and dose studied

Yogurt with added probiotic strains. The abstracts read give no strain names, amounts or trial lengths.

Who was studied

Adults with mild to moderate high cholesterol (meta-analysis); healthy adults (broader review).

Limits

Few and small trials. Control foods were not described in the abstract. Not shown for plain yogurt or for lowering heart attacks.

Why researchers looked

Some trials tested whether yogurt cultures could change blood fats.

Traditional use

Yogurt is eaten as a food in many places. Long use as food is not proof that it treats any condition.

Proposed mechanism Not established

Not shown in the abstracts read. The 2025 review says mechanism data are limited.

A proposed mechanism does not show that the effect happens in people.

See the Safety tab on live-culture products and weakened immunity.

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Inflammation markers in the blood (Greek yogurt and mixed dairy diets)

Very low certainty

Two small trials looked at blood markers of inflammation. In 30 young men training with weights, one marker (IL-6) was lower after 12 weeks with Greek yogurt than with a carbohydrate pudding. In a 6-week trial of a dairy mix that included skyr, the main marker did not change. Blood markers are not health outcomes.

2 studiesGreek yogurt after training; a mix of milk, skyr and cheddar. Not pla…

Studies, doses and limits

What the trials found

In a secondary analysis of a 12-week training trial, 30 healthy young men were randomised to Greek yogurt or an isoenergetic carbohydrate pudding after workouts. Time and training changed CRP, IL-1ra and IL-1 beta in both groups. At week 12, IL-6 was lower in the Greek yogurt group, while TNF-alpha and the TNF-alpha/IL-10 ratio were higher in the pudding group compared with earlier points. In a separate crossover trial of 30 adults with overweight or obesity, 3 servings a day of a mix of low-fat milk, skyr and full-fat cheddar for 6 weeks did not change IL-6 (the main outcome), but TNF-alpha fell and IL-4 rose, and body weight and fat did not change.

Results

Mixed and small. The yogurt-specific result is from one analysis in healthy young men. The mixed dairy trial cannot separate yogurt from milk and cheese.

Effect sizes as reported

Greek yogurt trial: IL-6 lower at week 12 vs pudding (no numbers in the abstract). Dairy mix trial: IL-6 no change; TNF-alpha lower (P = 0.042); IL-4 higher (P = 0.026).

Why this rating

Very low. Two small trials, markers rather than health outcomes, many markers tested, one a secondary analysis, and both with dairy industry ties declared by authors (Dairy Farmers of Canada, Lactalis).

Form and dose studied

Greek yogurt after training; a mix of milk, skyr and cheddar. Not plain yogurt alone.

Who was studied

Healthy young men (first trial); adults with overweight or obesity (second trial).

Limits

15 people per group in the first trial. The control was a pudding. The second trial found differences between men and women that need more study.

Why researchers looked

Dairy foods contain compounds that some researchers think may calm inflammation, and fermented dairy is one of the foods tested.

Traditional use

Yogurt is eaten as a food in many places. Long use as food is not proof that it treats any condition.

Proposed mechanism Hypothesis

Not shown. The authors suggest dairy components may play a role, but the abstracts do not test it.

A proposed mechanism does not show that the effect happens in people.

None specific.

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Gut bacteria and general gut health

Not enough evidence

Yogurt is made with live cultures, but the expert group ISAPP says a fermented food is not automatically a probiotic, and a probiotic has to be shown to give a benefit. We found no trial in the sources read showing that ordinary yogurt improves a gut condition or rebalances gut bacteria.

3 studiesNot applicable.

Studies, doses and limits

What the trials found

The 2021 ISAPP consensus statement defines fermented foods as foods made through desired microbial growth and enzymatic conversions of food components, and clarifies the difference between fermented foods and probiotics. The 2014 ISAPP statement keeps the FAO/WHO definition of a probiotic as live microorganisms that, when given in adequate amounts, confer a health benefit. The 2021 yogurt review mentions gastrointestinal health among its associations but gives no numbers in its abstract.

Results

No yogurt-specific gut result was found beyond lactose digestion. This is a gap in the evidence, not evidence of no effect.

Effect sizes as reported

No numbers.

Why this rating

Insufficient. The sources read are definitions and expert opinion, not trials of yogurt for a gut outcome.

Limits

Probiotic supplements are different products and were not reviewed here. Whether a particular shop yogurt still has live cultures was not studied in the sources read.

Why researchers looked

Yogurt is often marketed for gut health because of its live cultures.

Traditional use

Yogurt is eaten as a food in many places. Long use as food is not proof that it treats any condition.

Proposed mechanism Authoritative guidance

The ISAPP panel gives a mechanistic rationale for how fermented foods could help the gut, but the abstract does not name yogurt or test it.

A proposed mechanism does not show that the effect happens in people.

NCCIH says harm from probiotics is more likely in people with severe illness or weakened immune systems; see the Safety tab.

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Connections to the rest of health

How Yogurt 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

Kind of connection Connected to Search

A. Wellness goals

Connected to	Kind of connection	Evidence status	Context	Studies
Digestive Support	Demonstrated clinical effect	Moderate certainty	Lactose digestion and tolerance: In a small trial of 15 adults who digest lactose poorly, plain yogurt gave off much less breath hydrogen (a sign of undigested lactose) than the same amount of lactose in milk. A review of 108 studies says yogurt and lactose digestion are causally linked. Yogurt still contains lactose, so this is about tolerance, not a lactose-free food.	^{3 8 18}
Blood Sugar Balance		Low certainty	Long-term health links (diabetes, death rates, weight, bone, heart): People who eat more yogurt tend to have a lower risk of type 2 diabetes in large studies that follow people over time. For death from any cause, the main result was not significant. These studies show a link, not that yogurt causes it.	^{10 2 8}
Weight Management		Low certainty	Long-term health links (diabetes, death rates, weight, bone, heart): People who eat more yogurt tend to have a lower risk of type 2 diabetes in large studies that follow people over time. For death from any cause, the main result was not significant. These studies show a link, not that yogurt causes it.	^{10 2 8}
Bone Health		Low certainty	Long-term health links (diabetes, death rates, weight, bone, heart): People who eat more yogurt tend to have a lower risk of type 2 diabetes in large studies that follow people over time. For death from any cause, the main result was not significant. These studies show a link, not that yogurt causes it.	^{10 2 8}
Cholesterol Balance		Low certainty	Cholesterol (yogurt with added probiotic strains): A pooled analysis of 7 small trials found that yogurt with added probiotic strains lowered total and LDL ('bad') cholesterol by a small amount in people with mild to moderate high cholesterol. A wider review of fermented dairy called the evidence neither convincing nor sufficient.	^{6 12}
Inflammation Balance		Very low certainty	Inflammation markers in the blood (Greek yogurt and mixed dairy diets): Two small trials looked at blood markers of inflammation. In 30 young men training with weights, one marker (IL-6) was lower after 12 weeks with Greek yogurt than with a carbohydrate pudding. In a 6-week trial of a dairy mix that included skyr, the main marker did not change. Blood markers are not health outcomes.	^{1 7}
Gut Health		Not enough evidence	Gut bacteria and general gut health: Yogurt is made with live cultures, but the expert group ISAPP says a fermented food is not automatically a probiotic, and a probiotic has to be shown to give a benefit. We found no trial in the sources read showing that ordinary yogurt improves a gut condition or rebalances gut bacteria.	^{5 4 8}
Microbiome Balance		Not enough evidence	Gut bacteria and general gut health: Yogurt is made with live cultures, but the expert group ISAPP says a fermented food is not automatically a probiotic, and a probiotic has to be shown to give a benefit. We found no trial in the sources read showing that ordinary yogurt improves a gut condition or rebalances gut bacteria.	^{5 4 8}

B. Body systems

Connected to	Kind of connection	Evidence status	Context	Studies
Digestive System	Biological association	Moderate certainty	Studied for: Lactose digestion and tolerance Studied for: Gut bacteria and general gut health	^{3 8 18 5 4}
Endocrine System	Biological association	Low certainty	Studied for: Long-term health links (diabetes, death rates, weight, bone, heart)	^{10 2 8}
Cardiovascular System	Biological association	Low certainty	Studied for: Long-term health links (diabetes, death rates, weight, bone, heart) Studied for: Cholesterol (yogurt with added probiotic strains)	^{10 2 8 6 12}
Musculoskeletal System	Biological association	Low certainty	Studied for: Long-term health links (diabetes, death rates, weight, bone, heart)	^{10 2 8}
Immune System	Biological association	Very low certainty	Studied for: Inflammation markers in the blood (Greek yogurt and mixed dairy diets)	^{1 7}

E. Health conditions

Connected to	Kind of connection	Evidence status	Context	Studies
Cow's milk allergy	Adverse effect or risk	Documented risk	Yogurt is a milk food and is not safe for cow's milk allergy; challenge-verified allergy was about 0.3% in a European review. Preparation or compound: Milk protein in yogurt	^{15 11}
Lactose intolerance		Preliminary	Less undigested lactose after plain yogurt than after milk in a 15-person trial; NIDDK suggests trying it. Less undigested lactose after plain yogurt than after milk in a 15-person trial; NIDDK suggests trying yogurt. Preparation or compound: Yogurt as food	^{3 18}
Listeriosis	Adverse effect or risk	Documented risk	The NHS advises avoiding unpasteurised yoghurt in pregnancy because of listeria. Preparation or compound: Unpasteurised yogurt	¹⁶
High cholesterol		Preliminary	Probiotic yogurt lowered LDL in 7 small trials; a wider review of fermented dairy found the evidence not convincing. Not a treatment. Preparation or compound: Yogurt with added probiotic strains	^{6 12}

I. Biomarkers

Connected to	Kind of connection	Evidence status	Context	Studies
Breath hydrogen (a sign of undigested lactose)	Biological association	Moderate certainty	Measured in trials: lowered. A lab change is not the same as a health benefit.	³
LDL cholesterol	Biological association	Low certainty	Measured in trials: lowered. A lab change is not the same as a health benefit.	^{6 12}
Total cholesterol	Biological association	Low certainty	Measured in trials: lowered. A lab change is not the same as a health benefit.	⁶
Death from any cause	Biological association	Very low certainty	Measured in trials: no significant change. A lab change is not the same as a health benefit.	²
Interleukin-6 (IL-6)	Biological association	Very low certainty	Measured in trials: mixed. A lab change is not the same as a health benefit.	^{1 7}
Tumour necrosis factor alpha (TNF-alpha)	Biological association	Very low certainty	Measured in trials: lowered. A lab change is not the same as a health benefit.	^{7 1}
C-reactive protein (CRP)	Biological association	Very low certainty	Measured in trials: no significant change. A lab change is not the same as a health benefit.	¹

K. Biological pathways

Connected to	Kind of connection	Evidence status	Context	Studies
Calcium	Preliminary mechanism	Lab	Plain low-fat yogurt has 183 mg per 100 g by USDA data; absorption was not studied in the sources read.	¹⁹
Lactose	Preliminary mechanism	Human	The natural milk sugar in yogurt; breath hydrogen was lower after yogurt than after milk.	^{3 17}
Vitamin B-12	Preliminary mechanism	Lab	Plain low-fat yogurt has 0.56 micrograms per 100 g by USDA data.	¹⁹

L. Active compounds

Connected to	Kind of connection	Evidence status	Context	Studies
Milk protein	Biological association	Human	A source of protein. It is also the source of the milk allergen.	^{19 20 15}
Lactose	Biological association	Human	The natural milk sugar. People who digest it poorly had much less breath hydrogen after yogurt than after milk.	^{19 3 17}
Calcium	Biological association	Human	A nutrient in the food. How well it is absorbed from yogurt was not read.	^{19 20}
Vitamin B-12 and riboflavin (B2)	Biological association	Human	Nutrients in the food. No study read tested the effect of yogurt on B vitamin levels in people.	¹⁹
Live starter cultures	Biological association	Human	ISAPP says a fermented food is not automatically a probiotic; a probiotic must be shown to give a benefit.	^{5 4}

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).

Evidence at a glance: what changed in 5 lab markers

Tap a number to show only those markers. Counts are markers, not people.

Metabolic2 Inflammatory11 Other1

The evidence

The research centre for Yogurt. Every record here was checked against PubMed or the publisher's page; we never list a study we have not verified.

Evidence by outcome

Lactose digestion and tolerance 3 studies Moderate certainty Long-term health links (diabetes, death rates, weight, bone, heart) 3 studies Low certainty Cholesterol (yogurt with added probiotic strains) 2 studies Low certainty Inflammation markers in the blood (Greek yogurt and mixed dairy diets) 2 studies Very low certainty Gut bacteria and general gut health 3 studies Not enough evidence

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 yogurt summary, re-checked nutrition against saved USDA FoodData Central data, read health agency pages (NHS, NIDDK, NCCIH, WHO, MedlinePlus) and re-read PubMed abstracts for reviews, trials and a lab analysis. Only abstracts were read for studies. Items we could not verify are flagged in the research gaps.

Study library: every study we checked 21

Design Research type Year from Search

Study	Design	People	Product, dose, length	Result
Fraschetti 2025 Resistance Exercise Training and Greek Yogurt Consumption Modulate Markers of Systemic Inflammation in Healthy Young Males-A Secondary Analysis of a Randomized Controlled Trial. Nutrients · PMID 40944203 · DOI	Randomized trial secondary analysis	30 30 healthy young men doing 12 weeks of resistance and plyometric training	Greek yogurt after training Greek yogurt Not given in the abstract 12 weeks · vs Isoenergetic carbohydrate pudding	In both groups CRP and IL-1ra rose at week 1 and IL-1 beta fell by week 12 (effects of training and time). At week 12 IL-6 was lower in the Greek yogurt group, while TNF-alpha and the TNF-alpha/IL-10 ratio were higher in the pudding group compared with earlier points. The authors conclude that the programme benefited the markers and Greek yogurt may enhance this. IL-6 lower at week 12 with Greek yogurt vs pudding (no numbers in the abstract) (Not given in the abstract) Methods, limits and funding Outcomes: Blood inflammation markers: TNF-alpha, IL-6, IL-1ra, IL-1 beta, IL-10, CRP Limitations: A secondary analysis of a trial built for another question, 15 men per group, young healthy men only. Blood markers are not health outcomes. The control food was a pudding, not another dairy food or no food. Funding and conflicts: Funding listed: Brock University and an NSERC doctoral scholarship. The last author reports, for other projects, grants from Dairy Farmers of Canada and non-financial support from Lactalis. Read: abstract
Gao 2020 Yogurt Intake Reduces All-Cause and Cardiovascular Disease Mortality: A Meta-Analysis of Eight Prospective Cohort Studies. Chin J Integr Med · PMID 31970674 · DOI	Systematic review meta analysis	235676 8 prospective cohort studies, 235,676 people, 14,831 deaths	Yogurt eaten as food Yogurt Highest versus lowest intake; subgroup at 200 g a day or more Follow-up varied by study · vs Lowest intake group	Highest versus lowest intake was not significantly linked to death from any cause (HR 0.93), cardiovascular death (0.92) or cancer death (0.97). In the subgroup eating 200 g a day or more, the links were significant for any-cause death (HR 0.88) and cardiovascular death (HR 0.87). The authors' dose-response analysis at 200 g a day gave HR 0.95 for any-cause death (P = 0.041) and 0.92 for cardiovascular death (P = 0.009). Highest vs lowest: all-cause HR 0.93; CVD HR 0.92; cancer HR 0.97. At 200 g/day or more: all-cause HR 0.88; CVD HR 0.87 (All-cause 0.85 to 1.01; CVD 0.81 to 1.03; cancer 0.83 to 1.12; subgroup all-cause 0.80 to 0.96; subgroup CVD 0.77 to 0.99) Methods, limits and funding Outcomes: Death from any cause, from cardiovascular disease and from cancer Limitations: Observational, so it cannot show cause. The paper's title says yogurt reduces mortality, but its main result was not significant; only a subgroup and a dose-response curve were. Yogurt eaters may also differ in other habits. Funding and conflicts: Funding is not stated in the abstract. Read: abstract
Hertzler 2003 Kefir improves lactose digestion and tolerance in adults with lactose maldigestion. J Am Diet Assoc · PMID 12728216 · DOI	Randomized trial	15 15 healthy, free-living adults with lactose maldigestion	Plain and raspberry yogurt, plain and raspberry kefir, versus 2% milk, each giving 20 g lactose Yogurt and kefir as foods 20 g lactose in each test meal One test meal per session, 8 hours of monitoring · vs 2% reduced-fat milk	Breath hydrogen area under the curve was 224 (plus or minus 39) ppm x h for milk, 76 (plus or minus 14) for plain yogurt (P below .001), 87 (plus or minus 37) for plain kefir, and 76 (plus or minus 14) for flavoured yogurt (P = .005). Flavoured kefir was in between (156). Yogurts and kefirs cut perceived flatulence by 54% to 71% compared with milk. Abdominal pain and diarrhoea were negligible in all five meals. Plain yogurt 76 vs milk 224 ppm x h (breath hydrogen) (Not given in the abstract) Methods, limits and funding Outcomes: Breath hydrogen (a sign of undigested lactose) and symptoms Limitations: Only 15 people, all with lactose maldigestion, one single-meal test each, so it says nothing about long-term eating. The abstract names a randomized block design. Kefir was the main focus of the paper. Funding and conflicts: Funding is not stated in the abstract. Read: abstract
Hill 2014 Expert consensus document. The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic. Nat Rev Gastroenterol Hepatol · PMID 24912386 · DOI	Consensus statement n/a	Expert panel convened October 2013	Definition of probiotic	The panel reinforced the FAO/WHO definition of a probiotic as live microorganisms which, when given in adequate amounts, confer a health benefit on the host, and called for more precise use of the word to help clinicians and consumers tell products apart. No numbers (Not applicable) Methods, limits and funding Outcomes: Scope and use of the term probiotic Limitations: An expert opinion document from 2014. It does not mention yogurt in the abstract. Funding and conflicts: No conflicts declared in the record. 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	Consensus statement n/a	Expert panel convened September 2019	Fermented foods and drinks Fermented foods	The panel defined fermented foods and beverages as foods made through desired microbial growth and enzymatic conversions of food components, and clarified the difference between fermented foods and probiotics. It also reviewed safety, nutrition and a mechanistic rationale for how fermented foods could help gut and general health. No numbers (Not applicable) Methods, limits and funding Outcomes: Definition of fermented foods; safety, risks and health benefits Limitations: An expert opinion document, not a trial. The abstract does not name yogurt. Funding and conflicts: Many panel members declare industry consulting or research ties, including with dairy, probiotic and food companies (listed in the record). Read: abstract
Pourrajab 2020 The impact of probiotic yogurt consumption on lipid profiles in subjects with mild to moderate hypercholesterolemia: A systematic review and meta-analysis of randomized controlled trials. Nutr Metab Cardiovasc Dis · PMID 31748179 · DOI	Systematic review meta analysis	274 7 randomized trials, 274 people with mild to moderate high cholesterol (9 effect sizes)	Yogurt with added probiotic strains Probiotic yogurt Not given in the abstract Not given in the abstract · vs Control without probiotic yogurt (detail not given in the abstract)	Total cholesterol fell by 8.73 mg/dL and LDL by 10.611 mg/dL. HDL and triglycerides did not change significantly. The result held in a sensitivity analysis. Total cholesterol -8.73 mg/dL; LDL -10.611 mg/dL; HDL and triglycerides no significant change (Total cholesterol -15.98 to -1.48; LDL -16.529 to -4.693) Methods, limits and funding Outcomes: Total cholesterol, LDL, HDL and triglycerides Limitations: Small number of small trials. It applies to yogurt with added probiotic strains, not to every yogurt. The abstract does not give trial lengths or the control foods. Funding and conflicts: Funding is not stated in the abstract. Read: abstract
Prowting 2026 Inflammatory Cytokine Responses to 6 Wks of Increased Dairy Intake in Individuals with Overweight and Obesity-A Randomized Crossover Trial. J Nutr · PMID 41176279 · DOI	Randomized trial crossover	30 30 adults (18 women, 12 men) with overweight or obesity and heart or metabolic risk factors	A high-dairy diet: 3 servings a day of a mix of low-fat milk, Skyr yogurt and full-fat cheddar Mixed dairy including skyr 3 servings a day 6 weeks per diet, 4 weeks or more apart · vs Habitual low-dairy diet (1 serving a day or less)	IL-6 (the main outcome) did not change. TNF-alpha fell (P = 0.042) and IL-4 rose (P = 0.026) on the high-dairy diet. Nothing else changed, including body weight and fat, and vascular and metabolic measures. Men had higher IL-6, TNF-alpha, triglycerides and diastolic blood pressure on the high-dairy diet than women. IL-6 no change; TNF-alpha lower (P=0.042); IL-4 higher (P=0.026) (Not given in the abstract) Methods, limits and funding Outcomes: Inflammation markers (IL-6 primary), blood fats, blood pressure, body weight and fat Limitations: Small. Many outcomes tested. The dairy was a mix of foods, so the effect of yogurt cannot be separated. Differences between men and women need study. Funding and conflicts: Declared: support from Dairy Farmers of Canada and Lactalis Canada (products) for some authors, plus Canadian and Ontario public funding. Registered NCT04902417. Registration: NCT04902417 Read: abstract
Savaiano 2021 Yogurt, cultured fermented milk, and health: a systematic review. Nutr Rev · PMID 32447398 · DOI	Systematic review	108 studies published 1979 to 2017 on fermented milk products (yogurt and others), mixed designs	Yogurt and other fermented milks eaten as food Fermented milk foods · vs Mixed controls	76 of 108 studies reported a favourable outcome (67 of them of positive or neutral quality); 28 were not significant and 4 unfavourable. The authors state that a causal relationship exists between yogurt and lactose digestion and tolerance, and that there are consistent associations with lower risk of breast and colorectal cancer and type 2 diabetes, better weight maintenance and better heart, bone and gut health. Dairy in general, fermented or not, was linked with prostate cancer occurrence. 76 favourable, 28 not significant, 4 unfavourable (of 108 studies) (Not applicable) Methods, limits and funding Outcomes: Gut and heart health, cancer risk, weight, diabetes and metabolic health, bone density Limitations: A qualitative review without pooled numbers, by two authors who argue that fermented milks should be encouraged in national dietary guidelines. 602 of 1,057 abstracts were excluded. Most of the health links are associations. It covers fermented milks in general, not yogurt alone. Funding and conflicts: Funding is not stated in the abstract. PROSPERO CRD42017068953. Registration: CRD42017068953 Read: abstract
Silva 2019 Short communication: Biogenic amine formation during fermentation in functional sheep milk yogurts. J Dairy Sci · PMID 31351734 · DOI	Laboratory analysis n/a	Four lab-made sheep milk yogurts (natural, prebiotic, probiotic, synbiotic) with grumixama fruit pulp	Sheep milk yogurt made in the lab Lab-made yogurt Measured hourly during fermentation	In all four yogurts putrescine, cadaverine and spermidine fell, spermine stayed level and tyramine rose during fermentation. The authors conclude that fermentation of these functional sheep milk yogurts can produce tyramine. No numbers in the abstract (Not applicable) Methods, limits and funding Outcomes: Biogenic amines (putrescine, cadaverine, spermidine, spermine, tyramine), acidity, protein breakdown Limitations: A lab study of sheep milk yogurt with added fruit pulp, not shop yogurt and not cow milk. It did not measure the final amount or any effect in people. Funding and conflicts: Funding is not stated in the abstract. Read: abstract
Soedamah-Muthu 2018 Dairy Consumption and Cardiometabolic Diseases: Systematic Review and Updated Meta-Analyses of Prospective Cohort Studies. Curr Nutr Rep · PMID 30406514 · DOI	Systematic review meta analysis	Prospective cohort studies of dairy and diabetes, heart disease and stroke (nine new studies added to earlier analyses)	Dairy foods including yogurt, eaten as food Yogurt and other dairy Per 200 g a day for total dairy; 80 g a day for yogurt Cohort follow-up · vs Lower intake	Total dairy and low-fat dairy were linked to a 3% to 4% lower risk of diabetes per 200 g a day. Yogurt was inversely linked to diabetes in a non-linear way (RR 0.86 at 80 g a day). Total dairy and milk were not linked to coronary heart disease, and 200 g of milk a day was linked to 8% lower stroke risk. Yogurt and type 2 diabetes: RR 0.86 at 80 g/day (0.83 to 0.90) Methods, limits and funding Outcomes: Type 2 diabetes, coronary heart disease, stroke Limitations: Observational, so it cannot show cause. Dairy and non-dairy eaters can differ in many ways. Funding and conflicts: Declared: the first author received unrestricted grants for earlier meta-analyses from the Dutch Dairy Association, Global Dairy Platform, the Dairy Research Institute and Dairy Australia, and a dairy nutrition prize. The second author declares none. Read: abstract
Spolidoro 2023 Prevalence estimates of eight big food allergies in Europe: Updated systematic review and meta-analysis. Allergy · PMID 37405695 · DOI	Systematic review meta analysis	93 studies in Europe, all ages, eight major food allergens including cow's milk	Not applicable (prevalence study) Cow's milk allergy (all milk foods)	Self-reported lifetime cow's milk allergy was 5.7%. Food-challenge-verified cow's milk allergy (point prevalence) was 0.3%. The authors found that prevalence of allergy to common foods did not change much over the last decade, with some variation by region. Cow's milk: self-reported 5.7%; challenge-verified 0.3% (Self-reported 4.4 to 6.9%; challenge-verified 0.1 to 0.5%) Methods, limits and funding Outcomes: Prevalence of food allergy to cow's milk and seven other foods Limitations: Europe only. Most studies had moderate risk of bias. About milk in general, not yogurt specifically. Funding and conflicts: No conflicts declared in the record. Registered PROSPERO CRD42021266657. Registration: CRD42021266657 Read: abstract
Yilmaz 2025 Fermented dairy product consumption and blood lipid levels in healthy adults: a systematic review. Front Nutr · PMID 41019545 · DOI	Systematic review	68 studies: 14 controlled interventions, 37 non-controlled interventions and 17 observational studies, in healthy adults	Fermented dairy products (yogurt, kefir and others) Fermented dairy · vs Mixed	Findings from intervention studies were largely inconsistent, and most trials reported no significant change in lipids. A few reported modest reductions in total and LDL cholesterol, particularly with yogurt and kefir. Observational results were mixed. The authors rated overall study quality, consistency and mechanisms as neither convincing nor sufficient against EFSA criteria. No pooled numbers (Not applicable) Methods, limits and funding Outcomes: Blood lipids and cardiovascular disease Limitations: High risk of bias, varied designs, poorly described products and limited mechanism data. Covers fermented dairy in general. Funding and conflicts: Part of the COST Action CA20218 (PIMENTO). The authors declare no commercial or financial relationships; one author is a Frontiers editorial board member, which they say did not affect review. Registered at osf.io/h2mbe/. Registration: osf.io/h2mbe Read: abstract
s-medlineplus-foodallergy MedlinePlus: Food allergy · Source	Health agency n/a			Methods, limits and funding Read: full-text
s-nccih-probiotics NCCIH: Probiotics: Usefulness and Safety · Source	Health agency n/a			Methods, limits and funding Read: full-text
s-nhs-food-allergy NHS: Food allergy · Source	Health agency n/a			Methods, limits and funding Read: full-text
s-nhs-foods-to-avoid NHS: Foods to avoid in pregnancy · Source	Health agency n/a			Methods, limits and funding Read: full-text
s-nhs-lactose NHS: Lactose intolerance · Source	Health agency n/a			Methods, limits and funding Read: full-text
s-niddk-lactose NIDDK: Eating, Diet, & Nutrition for Lactose Intolerance · Source	Health agency n/a			Methods, limits and funding Read: full-text
s-usda-fdc-170886 USDA FoodData Central: Yogurt, plain, low fat (FDC 170886, SR Legacy, April 2018) · Source	Reference database n/a			Methods, limits and funding Read: full-text
s-usda-fdc-170894 USDA FoodData Central: Yogurt, Greek, plain, nonfat (FDC 170894, SR Legacy, April 2018) · Source	Reference database n/a			Methods, limits and funding Read: full-text
s-who-healthy-diet WHO: Healthy diet fact sheet · Source	Health agency n/a			Methods, limits and funding Read: full-text

What we do not know yet

No long-term trial of yogurt for diabetes, weight, bone, heart disease or cancer was found; those links are observational.
The cholesterol trials used yogurt with added probiotic strains; plain yogurt was not shown to lower cholesterol, and the abstracts give no strains, amounts or trial lengths.
No head-to-head trial of plain, Greek and flavoured yogurt on health outcomes was read.
No trial of ordinary yogurt for a gut condition or for changing gut bacteria was found in the sources read.
History, how shop yogurt is made, live-culture counts, breastfeeding, babies and children, kidney, histamine and FODMAP questions, contamination and liver safety were not researched.
The CDC Listeria page could not be read. The USDA values were read from a saved copy and only two plain items were used.

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 2

▼

LDL cholesterol

Lowered in trials

The 'bad' cholesterol carried in the blood. Higher levels are linked to more heart disease.

Low certainty

Results and what it means

Why it was measured

It is the usual blood marker used in diet trials for heart risk.

Statistical vs. clinical meaning

A small possible fall with probiotic yogurt that the wider review did not find convincing.

Safety implication

None specific.

Study	Result	People	Product
⁶	LDL -10.611 mg/dL (95% CI -16.529 to -4.693) with probiotic yogurt	7 trials, 274 people with mild to moderate high cholesterol	Yogurt with added probiotic strains (amounts not given in the abstract)
¹²	Most controlled trials of fermented dairy found no significant change; a few found modest falls with yogurt and kefir	68 studies in healthy adults	Fermented dairy products of many kinds

^{6 12}

▼

Total cholesterol

Lowered in trials

All the cholesterol carried in the blood, good and bad together.

Low certainty

Results and what it means

Why it was measured

A standard blood fat test, often reported alongside LDL.

Statistical vs. clinical meaning

A small average fall in small trials of probiotic yogurt only.

Safety implication

None specific.

Study	Result	People	Product
⁶	Total cholesterol -8.73 mg/dL (95% CI -15.98 to -1.48) with probiotic yogurt; HDL and triglycerides no significant change	7 trials, 274 people with mild to moderate high cholesterol	Yogurt with added probiotic strains

⁶

Inflammatory 3

↕

Interleukin-6 (IL-6)

Mixed results in trials

A signalling protein in the blood that rises with inflammation, and also rises after hard exercise.

Very low certainty

Results and what it means

Why it was measured

A common blood marker of inflammation in diet and exercise trials.

Statistical vs. clinical meaning

One analysis favoured Greek yogurt; the second trial found nothing. A blood marker, not a health result.

Safety implication

None specific.

Study	Result	People	Product
¹	IL-6 lower at week 12 in the Greek yogurt group than in the pudding group (no numbers in the abstract)	30 healthy young men in a 12-week training programme	Greek yogurt after training vs carbohydrate pudding
⁷	No change in IL-6 (primary outcome) on a high-dairy diet; higher IL-6 in men than women on that diet	30 adults with overweight or obesity	3 servings a day of milk, skyr and cheddar for 6 weeks vs low-dairy diet

^{1 7}

▼

Tumour necrosis factor alpha (TNF-alpha)

Lowered in trials

A signalling protein that drives inflammation.

Very low certainty

Results and what it means

Why it was measured

A second marker of inflammation in the same trials.

Statistical vs. clinical meaning

A small, uncertain difference in two small trials with many outcomes tested.

Safety implication

None specific.

Study	Result	People	Product
⁷	TNF-alpha decreased on the high-dairy diet compared with the low-dairy diet (P = 0.042)	30 adults with overweight or obesity	3 servings a day of milk, skyr and cheddar for 6 weeks
¹	TNF-alpha was higher at week 12 in the pudding group than at earlier points; the abstract does not report a fall in the Greek yogurt group	30 healthy young men in a 12-week training programme	Greek yogurt after training vs carbohydrate pudding

^{7 1}

●

C-reactive protein (CRP)

No significant change in trials

A protein made by the liver that rises with inflammation.

Very low certainty

Results and what it means

Why it was measured

A common routine blood test for inflammation.

Statistical vs. clinical meaning

No yogurt-specific change in CRP was reported in the abstract.

Safety implication

None specific.

Study	Result	People	Product
¹	CRP rose at week 1 in both groups and no difference between Greek yogurt and pudding was reported for CRP	30 healthy young men in a 12-week training programme	Greek yogurt after training vs carbohydrate pudding

Other 2

▼

Breath hydrogen (a sign of undigested lactose)

Lowered in trials

Hydrogen gas in the breath. It rises when lactose is not digested and gut bacteria ferment it.

Moderate certainty

Results and what it means

Why it was measured

It is the usual test for lactose maldigestion.

Statistical vs. clinical meaning

Less undigested lactose after yogurt than after milk in a small test.

Safety implication

None for lactose. Milk allergy is a different problem.

Study	Result	People	Product
³	Plain yogurt 76 (plus or minus 14) ppm x h versus milk 224 (plus or minus 39), P below .001	15 adults with lactose maldigestion	Test meals with 20 g lactose as plain yogurt or as milk, each after an overnight fast

●

Death from any cause

No significant change in trials

How many people in a group died, whatever the cause.

Very low certainty

Results and what it means

Why it was measured

It is the broadest outcome a long-term eating study can report.

Statistical vs. clinical meaning

The overall result was not significant; only a subgroup and a dose-response curve were. Observational, so no cause can be inferred.

Safety implication

None specific.

Study	Result	People	Product
²	Highest vs lowest intake HR 0.93 (95% CI 0.85 to 1.01), not significant; at 200 g/day or more HR 0.88 (0.80 to 0.96)	8 cohorts, 235,676 people, 14,831 deaths	Yogurt eaten as part of usual diets (observational)

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 5

Milk allergy: yogurt is a milk food. Cow's milk is one of the most common food allergens (NHS, MedlinePlus). A European review found self-reported cow's milk allergy in 5.7% of people and food-challenge-verified allergy in 0.3%. Fermenting milk into yogurt is not described as removing the allergen in the sources read. If you are allergic to cow's milk, yogurt is not safe for you. For swelling of the lips, mouth or throat, or trouble breathing, call 911 or your local emergency number (999 in the UK). Authoritative guidance ^{15 13 11}
Unpasteurised yogurt in pregnancy. The NHS lists pasteurised yoghurt as safe to eat in pregnancy and lists unpasteurised milk, cream, yoghurt, butter and ice cream as foods to avoid, because unpasteurised dairy may contain listeria, which can cause miscarriage or stillbirth. Most shop yogurt is made with pasteurised milk; check the label. Authoritative guidance ¹⁶
Lactose intolerance is not an allergy. Yogurt contains lactose (the NHS lists yoghurt among lactose-containing foods). NIDDK says some people with lactose intolerance find yogurt easier to tolerate than other milk products. Lactose intolerance causes digestive symptoms such as bloating and gas. It is not an immune reaction like milk allergy. A small trial found much less undigested lactose after plain yogurt than after milk in people who digest lactose poorly. Authoritative guidance ^{17 18 13 3}
Added sugar in flavoured yogurt. Flavoured and sweetened yogurts can contain added sugar. WHO advises keeping free sugars (which include sugars added by the maker) below 10% of daily energy, and says 5% or less may give added benefit. Plain yogurt has no added sugar, though it contains natural milk sugar (lactose): USDA lists 7.04 g of sugars per 100 g for plain low-fat yogurt. Read the label. Authoritative guidance ^{21 19}
Weakened immune system and live-culture products. NCCIH says probiotics have an extensive history of apparently safe use, mainly in healthy people, but that the risk of harm is greater in people with severe illness or compromised immune systems, and that severe or fatal infections have been reported. That statement is about probiotics in general. The sources read do not describe infections linked to yogurt itself. If your immune system is weak, ask your clinician about live-culture products. Authoritative guidance ¹⁴

Side effects 2

Effect	How often	Severity and recovery	Evidence
Allergic reaction to cow's milk protein, from mild itching or hives to anaphylaxis Prevalence data are for cow's milk in general, not yogurt specifically.	Europe, all ages: self-reported cow's milk allergy 5.7% (95% CI 4.4 to 6.9); food-challenge-verified 0.3% (0.1 to 0.5)	can be severe (anaphylaxis) Not described in the sources read.	Observational ^{11 15 13}
Bloating, gas and other digestive symptoms from lactose In the 15-person trial, abdominal pain and diarrhoea were negligible after the yogurts, and flatulence was lower than after milk.	No frequency given in the sources read.	mild Symptoms follow lactose intake; not described further.	Authoritative guidance ^{17 13 3}

Liver

No liver injury from eating yogurt 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 Yogurt 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 or aged foods can raise blood pressure when an MAOI is blocking its breakdown. A lab study of sheep milk yogurts found tyramine rose during fermentation, with no amounts in the abstract.	No source read states a yogurt and MAOI interaction or any case. The lab result is for lab-made sheep milk yogurt with fruit pulp, and it does not show how much tyramine shop yogurt holds or any effect on blood pressure.	Laboratory analysis Not enough evidence ⁹	If you take an MAOI, ask your prescriber or pharmacist which fermented foods you should avoid, and tell them if you eat yogurt.
Other prescription or over-the-counter medicines prescription	No mechanism was found in the sources read.	No yogurt-specific medicine interaction was found in the sources read. This is absence of evidence from a limited search, not proof of no interaction.	Not established Not enough evidence	Ask your pharmacist if a medicine label says to avoid dairy or to separate it from milk foods.

Who should check first 4

Situation	Advice	Evidence
Known or suspected cow's milk allergy	Avoid yogurt and other milk foods and read labels. Ask an allergist about your own case. For trouble breathing or swelling of the face, lips or throat, call 911 or your local emergency number.	Authoritative guidance ^{15 13}
Pregnancy	The NHS says pasteurised yoghurt is safe to eat and unpasteurised yoghurt is to be avoided. Check that the label says pasteurised, and ask your midwife or doctor about your own diet.	Authoritative guidance ¹⁶
Severe illness or a weakened immune system	NCCIH warns about probiotics in people with severe illness or weakened immunity. Ask your clinician about live-culture yogurts.	Authoritative guidance ¹⁴
Taking an MAOI antidepressant	No yogurt-specific warning was found. Ask your prescriber or pharmacist about fermented foods in your diet.	Laboratory analysis ⁹

Overdose, product quality and regulators

Summary. No toxicity from yogurt as an ordinary food was found in the sources read. The safety points are milk allergy, unpasteurised dairy in pregnancy, lactose, added sugar and live cultures in weak immunity.

Animal. Not reviewed.

High dose or long term signals. No harm signal was found for yogurt in the cohort studies read, but observational studies are not safety trials. The 2021 review links dairy in general, fermented or not, with prostate cancer occurrence.

Overdose response. Not found.

Genotoxicity. Not researched.

Food-safety risks of yogurt (spoilage, mould, contamination in unpasteurised dairy) were not researched beyond the pregnancy warning on unpasteurised yogurt.

Unpasteurised dairy and listeria. The NHS says unpasteurised dairy foods may contain listeria, which can cause listeriosis, miscarriage or stillbirth. ¹⁶

Body	Action	Date
NHS (UK) (United Kingdom)	Foods to avoid in pregnancy: pasteurised yoghurt is safe to eat; unpasteurised milk, cream, yoghurt, butter and ice cream are to be avoided because of listeria. source	2026-06-15
NHS (UK) (United Kingdom)	Food allergy: cows' milk is among the most common allergic foods; call 999 for signs of a serious reaction. source	2026-08-20
NHS (UK) (United Kingdom)	Lactose intolerance: lists yoghurt among foods that contain lactose; a food intolerance is different from a food allergy. source	2026-07-08
MedlinePlus (US National Library of Medicine) (United States)	Food allergy: cow's milk is listed first among the foods that cause most food allergies; call 911 for symptoms of anaphylaxis. source
NIDDK (US National Institutes of Health) (United States)	Eating, diet and nutrition for lactose intolerance: suggests trying yogurt and hard cheeses, which some people tolerate better than other milk products. source	2018-02
NCCIH (US National Institutes of Health) (United States)	Probiotics: usefulness and safety. Harm is more likely in people with severe illness or weakened immune systems; severe or fatal infections have been reported. source	2019-08
WHO (International)	Healthy diet fact sheet: limit free sugars to less than 10% of daily energy; 5% or less may give added benefit. source	2026-01-26

When to get medical help

Trouble breathing, wheezing, swelling of the lips, face, tongue or throat, widespread hives, repeated vomiting, dizziness or collapse after eating yogurt or another milk food (possible anaphylaxis): use epinephrine if prescribed, then call 911 or your local emergency number
Fever, muscle aches or flu-like illness during pregnancy after eating unpasteurised dairy (possible listeriosis): contact your midwife or doctor urgently

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 yogurt?

Yogurt is milk fermented by cultures of bacteria. Greek yogurt is strained to be thicker. It is eaten as a food, and a fermented food is not automatically a probiotic.

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Is yogurt easier to digest than milk if I am lactose intolerant?

Often, yes. In a small trial of 15 adults who digest lactose poorly, plain yogurt gave off about a third of the breath hydrogen that milk did, and flatulence was 54% to 71% lower. NIDDK says some people find yogurt easier to tolerate than other milk products. Yogurt still contains lactose.

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Is lactose intolerance the same as a milk allergy?

No. Lactose intolerance is a digestive problem with symptoms such as bloating and gas. A milk allergy is an immune reaction that can cause anaphylaxis. Yogurt is not safe for a cow's milk allergy.

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Does yogurt lower cholesterol?

Possibly a little, but only for yogurt with added probiotic strains. In 7 small trials, LDL was lower by about 10.6 mg/dL. A wider review of fermented dairy found the evidence neither convincing nor sufficient. Ordinary yogurt was not shown to lower cholesterol.

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Does eating yogurt prevent type 2 diabetes?

Large studies that follow people over time link more yogurt with lower diabetes risk (RR 0.86 at 80 g a day). That is an association. It does not prove that yogurt prevents diabetes.

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Does yogurt help you live longer?

Not shown. A pooled analysis of 8 studies found no significant link between highest versus lowest yogurt intake and death from any cause (HR 0.93, 0.85 to 1.01). A lower risk appeared only in a subgroup eating 200 g a day or more. These are observational studies.

Is yogurt a probiotic?

Not automatically. The expert group ISAPP says fermented foods and probiotics are different: a probiotic is a live microorganism that has been shown to give a health benefit. Whether your yogurt has live cultures depends on the product.

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Is Greek yogurt different from regular yogurt?

By USDA data, plain nonfat Greek yogurt has 10.19 g protein, 110 mg calcium and 3.24 g sugars per 100 g, against 5.25 g, 183 mg and 7.04 g for plain low-fat yogurt. We found no head-to-head trial of the two on health outcomes. One small trial used Greek yogurt and measured inflammation markers.

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Can I eat yogurt when pregnant?

The NHS says pasteurised yoghurt is safe to eat in pregnancy and unpasteurised yoghurt should be avoided because of listeria. Check the label, and ask your midwife or doctor about your own diet.

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Does flavoured yogurt have added sugar?

It can. WHO advises limiting free sugars, which include sugars added by the maker, to less than 10% of daily energy. Plain low-fat yogurt has 7.04 g of natural milk sugar per 100 g by USDA data. Read the Nutrition Facts label.

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Does yogurt interact with medicines?

We found no yogurt-specific interaction in the sources read. A lab study found tyramine rose during fermentation of lab-made sheep milk yogurts; if you take an MAOI antidepressant, ask your prescriber or pharmacist about fermented foods.

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Is yogurt safe if my immune system is weak?

Ask your clinician. NCCIH says harm from probiotics is more likely in people with severe illness or weakened immune systems. That statement is about probiotics in general, and no yogurt-specific infection was found in the sources read.

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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 yogurt summary, re-checked nutrition against saved USDA FoodData Central data, read health agency pages (NHS, NIDDK, NCCIH, WHO, MedlinePlus) and re-read PubMed abstracts for reviews, trials and a lab analysis. 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. Some authors of the studies cited declare ties to dairy bodies or companies (Dairy Farmers of Canada, Lactalis, Dutch Dairy Association and others); this is stated where each study is used. The authors of the main review argue that yogurt belongs in dietary guidelines.

Sources 21

Each source was opened and checked. Where we read only the abstract, it says so. The small numbers in the text point here.

Fraschetti EC, Abdul-Sater AA, Perry CGR, Josse AR. Resistance Exercise Training and Greek Yogurt Consumption Modulate Markers of Systemic Inflammation in Healthy Young Males-A Secondary Analysis of a Randomized Controlled Trial.. Nutrients. 2025. PMID 40944203. DOI 10.3390/nu17172816. (abstract)
Gao X, Jia HY, Chen GC, Li CY, et al.. Yogurt Intake Reduces All-Cause and Cardiovascular Disease Mortality: A Meta-Analysis of Eight Prospective Cohort Studies.. Chin J Integr Med. 2020. PMID 31970674. DOI 10.1007/s11655-020-3085-8. (abstract)
Hertzler SR, Clancy SM. Kefir improves lactose digestion and tolerance in adults with lactose maldigestion.. J Am Diet Assoc. 2003. PMID 12728216. DOI 10.1053/jada.2003.50111. (abstract)
Hill C, Guarner F, Reid G, Gibson GR, et al.. Expert consensus document. The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic.. Nat Rev Gastroenterol Hepatol. 2014. PMID 24912386. DOI 10.1038/nrgastro.2014.66. (abstract)
Marco ML, Sanders ME, Gänzle M, Arrieta MC, 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)
Pourrajab B, Fatahi S, Dehnad A, Kord Varkaneh H, et al.. The impact of probiotic yogurt consumption on lipid profiles in subjects with mild to moderate hypercholesterolemia: A systematic review and meta-analysis of randomized controlled trials.. Nutr Metab Cardiovasc Dis. 2020. PMID 31748179. DOI 10.1016/j.numecd.2019.10.001. (abstract)
Prowting JL, Fraschetti EC, Pereira TJ, Tucker JA, et al.. Inflammatory Cytokine Responses to 6 Wks of Increased Dairy Intake in Individuals with Overweight and Obesity-A Randomized Crossover Trial.. J Nutr. 2026. PMID 41176279. DOI 10.1016/j.tjnut.2025.10.040. (abstract)
Savaiano DA, Hutkins RW. Yogurt, cultured fermented milk, and health: a systematic review.. Nutr Rev. 2021. PMID 32447398. DOI 10.1093/nutrit/nuaa013. (abstract)
Silva VLM, Costa MP, Vieira CP, Conte-Junior CA. Short communication: Biogenic amine formation during fermentation in functional sheep milk yogurts.. J Dairy Sci. 2019. PMID 31351734. DOI 10.3168/jds.2019-16379. (abstract)
Soedamah-Muthu SS, de Goede J. Dairy Consumption and Cardiometabolic Diseases: Systematic Review and Updated Meta-Analyses of Prospective Cohort Studies.. Curr Nutr Rep. 2018. PMID 30406514. DOI 10.1007/s13668-018-0253-y. (abstract)
Spolidoro GCI, Ali MM, Amera YT, Nyassi S, et al.. Prevalence estimates of eight big food allergies in Europe: Updated systematic review and meta-analysis.. Allergy. 2023. PMID 37405695. DOI 10.1111/all.15801. (abstract)
Yilmaz B, Alvanoudi P, Kalogeropoulou A, Santa D, et al.. Fermented dairy product consumption and blood lipid levels in healthy adults: a systematic review.. Front Nutr. 2025. PMID 41019545. DOI 10.3389/fnut.2025.1651134. (abstract)
. MedlinePlus: Food allergy. . . (full-text)
. NCCIH: Probiotics: Usefulness and Safety. . . (full-text)
. NHS: Food allergy. . . (full-text)
. NHS: Foods to avoid in pregnancy. . . (full-text)
. NHS: Lactose intolerance. . . (full-text)
. NIDDK: Eating, Diet, & Nutrition for Lactose Intolerance. . . (full-text)
. USDA FoodData Central: Yogurt, plain, low fat (FDC 170886, SR Legacy, April 2018). . . (full-text)
. USDA FoodData Central: Yogurt, Greek, plain, nonfat (FDC 170894, SR Legacy, April 2018). . . (full-text)
. WHO: Healthy diet fact sheet. . . (full-text)

Education, not medical advice. This page is for general information. It does not diagnose or treat any condition and is not a substitute for care from a qualified health professional. Natural does not automatically mean safe. Ask a clinician or pharmacist before changing your care, especially if you take medication, are pregnant or breastfeeding, or have a health condition.