Functional Foods · Nut
Pistachios
Pistacia vera · also called Pistachio nuts, pistachio
Pistachios are the seeds of a tree and a tree nut. They give fibre, protein, unsaturated fat, copper and vitamin B6. In trials where pistachios replaced other foods, blood sugar, cholesterol and systolic blood pressure were a little lower on average, and body weight did not rise, but this is low-certainty blood-test evidence. The main cautions are tree nut allergy (often with cashew), choking in young children and mould in spoiled nuts.
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 Pistachios
Pistachios are the seeds of Pistacia vera, a tree nut. They are a food, not a proven remedy. Trials of pistachios eaten in place of other foods found small average changes in blood sugar, cholesterol and blood pressure, and no weight gain. Tree nut allergy is the main safety issue.
What it is
The pistachio eaten as food is the seed (kernel) of Pistacia vera L., a tree in the family Anacardiaceae, the same plant family as the cashew. GBIF lists the name as accepted. Pistachios are sold in the shell or shelled, raw, roasted, salted or flavoured, and are used in ice cream and baking.
USDA lists, per 100 g of raw shelled kernels: 560 kcal, 20.16 g protein, 45.32 g fat (5.907 g saturated), 27.17 g carbohydrate, 10.6 g fibre, 1025 mg potassium and 1 mg sodium. A 1-ounce serving (28.35 g, about 49 kernels) has about 159 kcal, 5.7 g protein, 12.9 g fat and 3 g fibre. USDA also lists 1.3 mg copper, 1.7 mg vitamin B6, 0.87 mg thiamin and 1.2 mg manganese per 100 g.
What the research shows
The evidence is from short randomised trials that measure blood tests, pooled in meta-analyses. In people at high cardiovascular risk, pistachios eaten in place of other foods, with calories matched, lowered fasting blood sugar by 5.32 mg/dL and insulin by 1.86 uIU/mL on average. Total cholesterol was 7.48 mg/dL lower, LDL 3.82 mg/dL lower and triglycerides 11.19 mg/dL lower in 12 trials. Systolic blood pressure was 2.12 to 3.10 mmHg lower in two meta-analyses.
These are small average changes. Differences between trials were very large for several results (I2 up to 99%), the reviews were all searched up to 2019 and may pool some of the same trials, and no abstract gives a formal certainty rating. A comparison of five nuts ranked pistachio first for LDL, triglycerides and total cholesterol, but the authors rate the evidence low quality and say the trials were few and small. That is not proof that pistachios beat other nuts.
Weight is a common worry because nuts are rich in calories. Three meta-analyses, one of them on pistachios, found no significant gain in weight, BMI or waist. In a 12-week trial in 60 women, those who ate a daily pistachio snack ate less of other foods and their weight did not change; the trial's funding is not stated in the abstract. No trial read measured heart attacks, strokes or diabetes diagnosis.
Food versus supplements
Every result here is for whole pistachio kernels eaten as food. No pistachio extract, oil, butter or supplement was tested in the sources read, so these findings do not apply to them. Roasted and salted pistachios were not compared with raw ones; salted or flavoured nuts can add sodium or sugar, so check the label.
At a glance
Traditional uses history, not proof
- Eaten as a snack and used in cooking, ice cream and baking
- Long use as food is not proof that it treats any condition
Studied for research
- Blood sugar and insulin, low certainty
- Cholesterol and triglycerides, low certainty
- Blood pressure, low certainty
- Body weight, moderate certainty of no weight gain
- Inflammation markers and blood vessel function, low certainty of no clear change
- Nutrient content, high certainty (food composition)
Main compounds
- Unsaturated fat
- Fibre
- Protein
- Phytosterols
- Copper, vitamin B6, thiamin and manganese
Common forms
- Raw shelled kernels (USDA values read)
- Whole pistachio kernels eaten as food (all trials read)
- Roasted, salted, flavoured, in-shell, butter and paste (nutrient values not read)
- Extracts, oils and supplements were not tested and are not covered
Research links: 2023 review: pistachios and blood sugar (8 trials) · 2023 review: pistachios and blood fats (12 trials) · 2025 review: tree nut and seed allergy · Research Library · Genes & Biomarkers Library
What it is and its history
- Accepted scientific name
- Pistacia vera L.
- Naming authority
- L. (GBIF accepted name)
- Common names
- Pistachio (English); Pistachio nut (English); Pistacho (Spanish)
- Family or group
- Anacardiaceae, as given by GBIF. GBIF puts cashew (Anacardium occidentale) in the same family, which fits the cashew-pistachio allergy link, though the allergy reviews read do not themselves give plant family as the reason.
- Classification
- Plantae > Tracheophyta > Magnoliopsida > Sapindales > Anacardiaceae > Pistacia > Pistacia vera
- 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.; Fruit: The pistachio eaten as food is the seed (kernel) of Pistacia vera, sold in the shell or shelled. USDA household portions: 1 ounce (28.35 g, about 49 kernels), 1 cup (123 g) and 1 kernel (0.7 g), all for shelled raw kernels.
- Cultivation
- Not verified from a source read. The 2021 mycotoxin review (PMC) says Iran and the United States were the largest producers in 2019 (337,000 and 335,000 tons).
- Harvest and processing
- Sold raw, roasted, salted or flavoured, in the shell or shelled, and used in ice cream and baking (2021 mycotoxin review). Pistachio butter or paste was not read.
- Sustainability and conservation
- Not researched.
Photographs
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 |
|---|---|---|---|---|
| Unsaturated fat | fat | Kernel USDA per 100 g: 45.32 g fat; 23.257 g monounsaturated, 14.38 g polyunsaturated (linoleic acid 14.091 g), 5.907 g saturated | Most of the fat is unsaturated. No study read tested this fat on its own. 18 | Nutrient database |
| Fibre | carbohydrate | Kernel USDA per 100 g: 10.6 g (about 3.0 g per ounce) | Amount only; no study read tested pistachio fibre. 18 | Nutrient database |
| Protein | protein | Kernel USDA per 100 g: 20.16 g (about 5.7 g per ounce). Also the source of the nut allergens. | Food protein; the allergens are proteins in tree nuts (the allergy reviews read do not name which proteins in pistachio). 18 11 | Nutrient database |
| Phytosterols (plant sterols) | sterol | Kernel USDA per 100 g: 214 mg (about 61 mg per ounce) | Amount only; no study read tested what they do in pistachios. 18 | Nutrient database |
| Copper, vitamin B6, thiamin and manganese | minerals and vitamins | Kernel USDA per 100 g: copper 1.3 mg, vitamin B6 1.7 mg, thiamin 0.87 mg, manganese 1.2 mg | Nutrient amounts only. A 12-week trial found higher intake of these nutrients among women who ate a daily pistachio snack. 18 2 | Nutrient database |
| Potassium and phosphorus | minerals | Kernel USDA per 100 g: potassium 1025 mg, phosphorus 490 mg | Relevant to people on dialysis; see the Safety tab. 18 17 | Nutrient database |
Absorption, metabolism and elimination
- Absorption
- Not found.
- Distribution
- Not found.
- Metabolism
- Not found.
- Elimination
- Not found.
- Bioavailability
- Not established for pistachio nutrients in the sources read.
Isolated compounds versus whole extracts
Every result on this page is for whole pistachio kernels eaten as food, swapped for other foods in most trials. No pistachio extract, oil, butter or supplement was tested in the sources read, so nothing here applies to those products.
Nutritional composition
Nutrition from USDA FoodData Central, Nuts, pistachio nuts, raw (FDC 170184, SR Legacy, April 2018 release), read 2026-10-26 from a saved copy of the USDA data, not the live website. Per 100 g shelled raw kernels: 560 kcal, 20.16 g protein, 45.32 g fat (5.907 g saturated), 27.17 g carbohydrate (7.66 g sugars), 10.6 g fibre, 1 mg sodium, 1025 mg potassium, 105 mg calcium, 3.92 mg iron, 121 mg magnesium, 490 mg phosphorus, 2.2 mg zinc, 1.2 mg manganese, 1.3 mg copper, 7 micrograms selenium, 1.7 mg vitamin B6, 0.87 mg thiamin, 51 micrograms folate (DFE), 2.86 mg vitamin E and 214 mg phytosterols. One typical USDA portion, 1 ounce (28.35 g, about 49 kernels; the 100 g values multiplied by 0.2835): about 159 kcal, 5.7 g protein, 12.9 g fat (1.7 g saturated), 7.7 g carbohydrate (2.2 g sugars), 3.0 g fibre, 0.3 mg sodium, 291 mg potassium, 139 mg phosphorus, 34 mg magnesium, 0.37 mg copper, 0.48 mg vitamin B6, 0.25 mg thiamin and 0.34 mg manganese. Roasted, salted, flavoured, in-shell and butter or paste products were not read; roasted and salted nuts can differ, for example in sodium, so check the label.
1 high certainty1 moderate certainty4 low certainty
What was looked at
The 6 benefits and uses checked for Pistachios, each with how strong the evidence is. Tap one to open it.
- Blood sugar and insulinLow certainty
- Cholesterol and triglyceridesLow certainty
- Blood pressureLow certainty
- Body weight and waist sizeModerate certainty
- Inflammation markers and blood vessel functionLow certainty
- Nutrients in pistachios (what is in the food)High certainty
Lab markers tracked in the studies
Fasting blood sugarFasting insulinHbA1cLDL cholesterolTriglyceridesHDL cholesterolSystolic blood pressureDiastolic blood pressureBody weightWaist circumferenceC-reactive proteinFlow-mediated dilation
What is Pistachios good for?
The main studied uses and how strong the human evidence is for each. All results are for whole pistachios eaten as food, mostly in place of other foods, and they are blood-test changes.
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.
Blood sugar and insulin
Low certaintyIn trials where pistachios replaced other foods, fasting blood sugar and fasting insulin were lower on average. The insulin resistance score did not change. These are blood-test changes in short trials, mostly in people at higher risk of heart disease.
2 studiesWhole pistachio kernels eaten as food in place of other foods. No ext…
Studies, doses and limits
What the trials found
A meta-analysis of 8 randomised trials (people at high risk of cardiovascular disease) and a meta-analysis of 11 trials found lower fasting blood sugar and insulin with pistachio-enriched diets. The 8-trial analysis found no change in the insulin resistance score (HOMA-IR). Differences between trials were very large in the 11-trial analysis (I2 up to 99%).
Results
Pistachios eaten in place of other foods, with calories matched: fasting blood sugar 5.32 mg/dL lower and insulin 1.86 uIU/mL lower on average (8 trials). In the 11-trial analysis: blood sugar 3.73 mg/dL lower, HbA1c 0.14 lower, insulin 2.43 lower.
Effect sizes as reported
Fasting blood sugar WMD -5.32 mg/dL (95% CI -7.80 to -2.64); insulin WMD -1.86 uIU/mL (-3.13 to -0.59); HOMA-IR -0.66 (-1.89 to 0.58, not significant). 11-trial analysis: fasting blood sugar -3.73 (-6.99 to -0.46); HbA1c -0.14 (-0.26 to -0.02); insulin -2.43 (-4.85 to -0.001).
Why this rating
Neither abstract gives a formal certainty rating. Both rest on a small number of short trials, the 11-trial analysis shows very high differences between trials (I2 up to 99%), the authors note few trials in people with diabetes, and one result only just reaches significance.
Form and dose studied
Whole pistachio kernels eaten as food in place of other foods. No extract or supplement was tested in the reviews read.
Who was studied
Adults, mainly people at high risk of cardiovascular disease. Few trials in people with diabetes.
Limits
Blood tests, not diabetes diagnoses or complications. Short trials. Very high differences between trials. Results may not apply to other groups.
Why researchers looked
Nuts are low in sugar and rich in fat, fibre and protein, so researchers test what happens to blood sugar when people eat them in place of other foods.
Traditional use
Pistachios are eaten as a snack and in cooking. Long use as food is not proof that they treat any condition.
Proposed mechanism Not established
No mechanism was read for this page. The trials measured blood tests only.
A proposed mechanism does not show that the effect happens in people.
Tree nut allergy comes first; see the Safety tab. Not a replacement for diabetes medicine.
Cholesterol and triglycerides
Low certaintyIn pooled trials, pistachio-enriched diets lowered total cholesterol, LDL ("bad") cholesterol and triglycerides a little, and did not significantly change HDL. A comparison of nut types ranked pistachio first, but the authors rate that evidence as low quality.
3 studiesWhole pistachio kernels eaten as food, compared with control diets or…
Studies, doses and limits
What the trials found
A meta-analysis of 12 randomised trials found lower total cholesterol, LDL and triglycerides and no significant change in HDL. A network meta-analysis of 34 trials (1,677 participants) compared five nuts: the pistachio diet ranked best for triglycerides, LDL and total cholesterol, with walnut second for triglycerides and total cholesterol and almond second for LDL. The authors rate the quality of that evidence as low and call the trials few, small and poorly reported. The 11-trial analysis also found lower TC/HDL and LDL/HDL ratios.
Results
Pistachio eating: total cholesterol 7.48 mg/dL lower, LDL 3.82 mg/dL lower, triglycerides 11.19 mg/dL lower on average (12 trials). HDL +2.45 mg/dL, not significant.
Effect sizes as reported
Total cholesterol WMD -7.48 mg/dL (-12.62 to -2.34); LDL -3.82 mg/dL (-5.49 to -2.16); triglycerides -11.19 mg/dL (-14.21 to -8.17); HDL +2.45 mg/dL (-2.44 to 7.33). Network meta-analysis SUCRA for pistachio: triglycerides 85%, LDL 87%, total cholesterol 96%.
Why this rating
The network meta-analysis authors rate the evidence quality as low. The 12-trial analysis gives no formal rating. Trials were small and short, and the changes are small on average. A top ranking is not proof that pistachios beat other nuts.
Form and dose studied
Whole pistachio kernels eaten as food, compared with control diets or other nuts. No extract or supplement was tested.
Who was studied
Adults in the pooled trials.
Limits
Blood fats are markers; no trial read measured heart attacks or strokes. Small average changes. Low-quality evidence for the nut comparison.
Why researchers looked
Nuts are rich in unsaturated fats, fibre and plant sterols, and nut eating is a common subject in heart-diet research.
Traditional use
Pistachios are eaten as a snack and in cooking. Long use as food is not proof that they treat any condition.
Proposed mechanism Not established
No mechanism was read for this page. USDA lists mostly unsaturated fat, fibre and plant sterols (phytosterols) in pistachios, but no study read tested what drives the blood fat changes.
A proposed mechanism does not show that the effect happens in people.
Tree nut allergy comes first; see the Safety tab. Not a replacement for cholesterol medicine.
Blood pressure
Low certaintyTwo meta-analyses found systolic blood pressure about 2 to 3 mmHg lower with pistachio-enriched diets. Diastolic pressure did not change in the 13-trial analysis. This is a small average change.
2 studiesWhole pistachio kernels eaten as food. No extract or supplement was t…
Studies, doses and limits
What the trials found
An 11-trial meta-analysis (506 people) found systolic pressure 3.10 mmHg lower. A later 13-trial meta-analysis (563 people) found 2.12 mmHg lower, with no significant change in diastolic pressure or in flow-mediated dilation, a test of blood vessel function.
Results
Systolic blood pressure about 2 to 3 mmHg lower on average. Diastolic pressure unchanged.
Effect sizes as reported
Systolic BP MD -2.12 mmHg (95% CI -3.65 to -0.59) in 13 trials; WMD -3.10 mmHg (-5.35 to -0.85, I2 63%) in 11 trials. Diastolic BP +0.32 mmHg (-1.37 to 2.02, not significant).
Why this rating
No formal certainty rating in either abstract. Small average change in short trials, with moderate differences between trials (I2 63% in the 11-trial analysis). The two analyses may include some of the same trials (not checked), so they may not be independent.
Form and dose studied
Whole pistachio kernels eaten as food. No extract or supplement was tested.
Who was studied
Adults in the pooled trials.
Limits
Blood pressure readings, not strokes or heart attacks. The size of the change is small and differs between the two reviews.
Why researchers looked
Nuts are studied for heart health, and blood pressure is an easy marker to measure in trials.
Traditional use
Pistachios are eaten as a snack and in cooking. Long use as food is not proof that they treat any condition.
Proposed mechanism Not established
No mechanism was read for this page.
A proposed mechanism does not show that the effect happens in people.
Not a replacement for blood pressure medicine. Salted or flavoured pistachios add sodium; check the label. See the Safety tab.
Body weight and waist size
Moderate certaintyPistachios and nuts in general are high in calories, but pooled trials did not find weight gain. In a 12-week trial in women, those who ate pistachios ate less of other foods and their weight did not change. This does not show that pistachios help with weight loss.
5 studiesWhole pistachio kernels (pistachio meta-analysis and one trial) and n…
Studies, doses and limits
What the trials found
A 13-trial pistachio meta-analysis (563 people) found no significant change in weight, BMI or waist. A 33-trial meta-analysis of nuts in general and a 105-trial network meta-analysis of tree nuts and peanuts also found no significant weight gain (hazelnut diets raised waist size; almond diets lowered waist size compared with control and with pistachio diets). One 12-week trial in 60 healthy women found weight and body composition unchanged.
Results
No significant gain in body weight, BMI or waist with pistachio or other nut diets in pooled trials.
Effect sizes as reported
Pistachio meta-analysis: weight MD +0.09 kg (95% CI -0.38 to 0.69); BMI +0.07 (-0.16 to 0.31); waist +0.77 cm (-0.09 to 1.64); all not significant. All nuts (33 trials): weight -0.47 kg (-1.17 to 0.22); BMI -0.40 (-0.97 to 0.17); waist -1.25 cm (-2.82 to 0.31); all not significant.
Why this rating
Three meta-analyses agree on no significant weight gain and the 33-trial analysis showed little difference between trials (I2 7% for weight). No abstract gives a formal rating, and most trials were short. This is moderate confidence in "no weight gain", not in weight loss.
Form and dose studied
Whole pistachio kernels (pistachio meta-analysis and one trial) and nuts of all kinds (the other two reviews).
Who was studied
Adults; the single trial was in healthy pre-menopausal women who did not usually eat nuts.
Limits
Trials last weeks to months. The trial authors say people ate less of other foods; real life may differ. The women's trial's funding is not stated in the abstract (see Evidence tab).
Why researchers looked
People worry that calorie-dense nuts will cause weight gain, so trials measure weight, BMI and waist size.
Traditional use
Pistachios are eaten as a snack and in cooking. Long use as food is not proof that they treat any condition.
Proposed mechanism Human observation
In the 12-week trial, women ate less carbohydrate and starch from other foods and felt less hungry after the pistachio snack. That is the trial authors' description of what happened, not a tested mechanism.
A proposed mechanism does not show that the effect happens in people.
USDA lists 560 kcal per 100 g, about 159 kcal in a 1-ounce serving of shelled kernels.
Inflammation markers and blood vessel function
Low certaintyIn 13 pooled trials, pistachios did not significantly change C-reactive protein, TNF-alpha (two inflammation markers) or flow-mediated dilation (a test of how well blood vessels widen).
2 studiesWhole pistachio kernels eaten as food.
Studies, doses and limits
What the trials found
The 13-trial meta-analysis found no significant change in C-reactive protein, TNF-alpha or flow-mediated dilation. The 11-trial analysis reported a lower level of a marker of oxidative stress (MDA), which is a lab marker, not a symptom.
Results
No clear change in the inflammation markers or in flow-mediated dilation. The oxidative stress marker MDA was lower in the 11-trial analysis.
Effect sizes as reported
CRP 0.00 mg/L (95% CI -0.21 to 0.23); TNF-alpha -0.09 pg/mL (-0.38 to 0.20); flow-mediated dilation +0.94% (-0.99 to 2.86); all not significant. MDA WMD -0.36 (-0.49 to -0.23, I2 0%).
Why this rating
A no-effect finding from a small set of short trials; no formal certainty rating in the abstracts. The authors of the 11-trial analysis say the effect on blood vessel function remains unclear.
Form and dose studied
Whole pistachio kernels eaten as food.
Who was studied
Adults in the pooled trials.
Limits
Surrogate markers only. Few trials measured these outcomes.
Why researchers looked
Researchers test whether nut eating changes inflammation and blood vessel function, which are linked to heart risk.
Traditional use
Pistachios are eaten as a snack and in cooking. Long use as food is not proof that they treat any condition.
Proposed mechanism Not established
No mechanism was read for this page.
A proposed mechanism does not show that the effect happens in people.
None specific.
Nutrients in pistachios (what is in the food)
High certaintyBy USDA data, a 1-ounce serving of shelled raw pistachios (about 49 kernels, 28 g) has about 159 kcal, 5.7 g of protein, 3 g of fibre and 12.9 g of fat, mostly unsaturated. It is high in copper, vitamin B6, thiamin and manganese.
2 studiesRaw shelled kernels (USDA item). Roasted, salted, flavoured, in-shell…
Studies, doses and limits
What the trials found
No trial read showed that eating pistachios corrects a low nutrient level. One 12-week trial found that women who ate a daily pistachio snack had higher intakes of several fats, thiamin, vitamin B6, copper, manganese and zinc, even though they ate less of other foods.
Results
Pistachios are a source of copper, vitamin B6, thiamin, manganese, fibre and protein on paper. How much of each your body takes up was not studied in the sources read.
Effect sizes as reported
USDA per 100 g raw shelled kernels: 560 kcal, 20.16 g protein, 45.32 g fat (5.907 g saturated), 10.6 g fibre, 1025 mg potassium, 1.3 mg copper, 1.7 mg vitamin B6, 0.87 mg thiamin, 1.2 mg manganese, 214 mg phytosterols. Per 1 ounce (28.35 g): about 159 kcal, 5.7 g protein, 12.9 g fat, 3.0 g fibre, 291 mg potassium, 0.37 mg copper, 0.48 mg vitamin B6.
Why this rating
High that the food contains these nutrients (USDA data). Not tested as a treatment for any shortfall, and absorption was not studied in the sources read.
Form and dose studied
Raw shelled kernels (USDA item). Roasted, salted, flavoured, in-shell, pistachio butter and paste were not read.
Who was studied
General adult diet.
Limits
Nutrient facts, not trials. Roasted and salted nuts differ from the raw USDA item, for example in sodium.
Why researchers looked
People eat pistachios as a snack and for the nutrients in them.
Traditional use
Pistachios are eaten as a snack and in cooking. Long use as food is not proof that they treat any condition.
Proposed mechanism Nutrient database
These are nutrient amounts in the food, taken from a USDA table.
A proposed mechanism does not show that the effect happens in people.
Tree nut allergy; see the Safety tab. Potassium and phosphorus matter for some people with kidney disease.
Connections to the rest of health
How Pistachios 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 Sugar Balance | Low certainty | Blood sugar and insulin: In trials where pistachios replaced other foods, fasting blood sugar and fasting insulin were lower on average. The insulin resistance score did not change. These are blood-test changes in short trials, mostly in people at higher risk of heart disease. | 6 5 | |
| Metabolic Health | Low certainty | Blood sugar and insulin: In trials where pistachios replaced other foods, fasting blood sugar and fasting insulin were lower on average. The insulin resistance score did not change. These are blood-test changes in short trials, mostly in people at higher risk of heart disease. | 6 5 | |
| Cholesterol Balance | Low certainty | Cholesterol and triglycerides: In pooled trials, pistachio-enriched diets lowered total cholesterol, LDL ("bad") cholesterol and triglycerides a little, and did not significantly change HDL. A comparison of nut types ranked pistachio first, but the authors rate that evidence as low quality. | 7 10 5 | |
| Heart Health | Low certainty | Cholesterol and triglycerides: In pooled trials, pistachio-enriched diets lowered total cholesterol, LDL ("bad") cholesterol and triglycerides a little, and did not significantly change HDL. A comparison of nut types ranked pistachio first, but the authors rate that evidence as low quality. Blood pressure: Two meta-analyses found systolic blood pressure about 2 to 3 mmHg lower with pistachio-enriched diets. Diastolic pressure did not change in the 13-trial analysis. This is a small average change. | 7 10 5 1 | |
| Blood Pressure Support | Low certainty | Blood pressure: Two meta-analyses found systolic blood pressure about 2 to 3 mmHg lower with pistachio-enriched diets. Diastolic pressure did not change in the 13-trial analysis. This is a small average change. | 5 1 | |
| Weight Management | Moderate certainty | Body weight and waist size: Pistachios and nuts in general are high in calories, but pooled trials did not find weight gain. In a 12-week trial in women, those who ate pistachios ate less of other foods and their weight did not change. This does not show that pistachios help with weight loss. | 1 4 3 2 18 | |
| Inflammation Balance | Low certainty | Inflammation markers and blood vessel function: In 13 pooled trials, pistachios did not significantly change C-reactive protein, TNF-alpha (two inflammation markers) or flow-mediated dilation (a test of how well blood vessels widen). | 1 5 | |
| Healthy Circulation | Low certainty | Inflammation markers and blood vessel function: In 13 pooled trials, pistachios did not significantly change C-reactive protein, TNF-alpha (two inflammation markers) or flow-mediated dilation (a test of how well blood vessels widen). | 1 5 | |
| Preventive Wellness | High certainty | Nutrients in pistachios (what is in the food): By USDA data, a 1-ounce serving of shelled raw pistachios (about 49 kernels, 28 g) has about 159 kcal, 5.7 g of protein, 3 g of fibre and 12.9 g of fat, mostly unsaturated. It is high in copper, vitamin B6, thiamin and manganese. | 18 2 |
B. Body systems
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Blood Sugar Support | Biological association | Low certainty | Studied for: Blood sugar and insulin | 6 5 |
| Cardiovascular System | Biological association | Low certainty | Studied for: Cholesterol and triglycerides Studied for: Blood pressure | 7 10 5 1 |
| Metabolic System | Biological association | Moderate certainty | Studied for: Body weight and waist size Studied for: Nutrients in pistachios (what is in the food) | 1 4 3 2 18 |
E. Health conditions
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Food allergy | Adverse effect or risk | Documented risk | Tree nuts are a major food allergen; about 1% of people in the US have tree nut allergy. Preparation or compound: Pistachios as food (tree nut) |
13 11 |
| Anaphylaxis | Adverse effect or risk | Documented risk | Tree nut allergies are often severe; epinephrine is first-line treatment for anaphylaxis. Preparation or compound: Pistachios as food (tree nut) |
8 |
| Choking | Adverse effect or risk | Documented risk | The NHS says not to give whole nuts to children under 5. Preparation or compound: Whole nuts |
16 |
| Aflatoxin exposure | Adverse effect or risk | Documented risk | WHO names pistachio among nuts regularly contaminated with aflatoxins. Preparation or compound: Mouldy or poorly stored pistachios |
19 12 |
| Chronic kidney disease | Guidance | Most people with chronic kidney disease do not need to limit nuts; people on hemodialysis may be advised to. Preparation or compound: Pistachios as food |
17 | |
| High cholesterol | Preliminary | Pooled trials found slightly lower LDL, total cholesterol and triglycerides; low-certainty blood-test evidence, not a treatment. Preparation or compound: Whole pistachios |
7 10 | |
| High blood pressure | Preliminary | Pooled trials found systolic pressure about 2 to 3 mmHg lower; not a replacement for medicine. Preparation or compound: Whole pistachios |
5 1 |
I. Biomarkers
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Fasting blood sugar | Biological association | Low certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 6 5 |
| Fasting insulin | Biological association | Low certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 6 5 |
| HbA1c | Biological association | Low certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 5 |
| LDL cholesterol | Biological association | Low certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 7 10 |
| Triglycerides | Biological association | Low certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 7 10 |
| HDL cholesterol | Biological association | Low certainty | Measured in trials: no clear change. A lab change is not the same as a health benefit. | 7 |
| Systolic blood pressure | Biological association | Low certainty | Measured in trials: lowered. A lab change is not the same as a health benefit. | 5 1 |
| Diastolic blood pressure | Biological association | Low certainty | Measured in trials: no clear change. A lab change is not the same as a health benefit. | 1 |
| Body weight | Biological association | Moderate certainty | Measured in trials: no clear change. A lab change is not the same as a health benefit. | 1 4 2 |
| Waist circumference | Biological association | Low certainty | Measured in trials: no clear change. A lab change is not the same as a health benefit. | 1 3 |
| C-reactive protein | Biological association | Low certainty | Measured in trials: no clear change. A lab change is not the same as a health benefit. | 1 |
| Flow-mediated dilation | Biological association | Low certainty | Measured in trials: no clear 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 |
|---|---|---|---|---|
| LDL cholesterol | Preliminary mechanism | Human | A little lower in pooled pistachio trials. | 7 10 |
| Systolic blood pressure | Preliminary mechanism | Human | About 2 to 3 mmHg lower in pooled trials. | 5 1 |
| Fasting blood sugar and insulin | Preliminary mechanism | Human | Lower in pooled trials of people at higher cardiovascular risk. | 6 |
L. Active compounds
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Unsaturated fat | Biological association | Nutrient database | Most of the fat is unsaturated. No study read tested this fat on its own. Preparation or compound: Kernel |
18 |
| Fibre | Biological association | Nutrient database | Amount only; no study read tested pistachio fibre. Preparation or compound: Kernel |
18 |
| Protein | Biological association | Nutrient database | Food protein; the allergens are proteins in tree nuts (the allergy reviews read do not name which proteins in pistachio). Preparation or compound: Kernel |
18 11 |
| Phytosterols (plant sterols) | Biological association | Nutrient database | Amount only; no study read tested what they do in pistachios. Preparation or compound: Kernel |
18 |
| Copper, vitamin B6, thiamin and manganese | Biological association | Nutrient database | Nutrient amounts only. A 12-week trial found higher intake of these nutrients among women who ate a daily pistachio snack. Preparation or compound: Kernel |
18 2 |
| Potassium and phosphorus | Biological association | Nutrient database | Relevant to people on dialysis; see the Safety tab. Preparation or compound: Kernel |
18 17 |
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 Pistachios. 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 pistachio page and nutrient summary, re-read USDA FoodData Central values from a saved copy of the data, read the health agency pages (FDA, MedlinePlus, WHO, NHS, National Kidney Foundation) and re-read PubMed abstracts for the reviews and the trial. Only abstracts were read for PubMed studies, plus the full text of one mycotoxin review. Items we could not verify are flagged in the research gaps.
Study library: every study we checked 19
| Study | Design | People | Product, dose, length | Result |
|---|---|---|---|---|
| Asbaghi 2021 Effects of pistachios on anthropometric indices, inflammatory markers, endothelial function and blood pressure in adults: a systematic review and meta-analysis of randomised controlled trials. Br J Nutr · PMID 33198823 · DOI |
Systematic review meta analysis |
13 randomised trials, 563 participants Adults |
Whole pistachio kernels eaten as food Kernel (food) Not given in the abstract Not given in the abstract · vs Control diets |
Pistachio eating lowered systolic blood pressure a little. Diastolic pressure, blood vessel function (flow-mediated dilation), C-reactive protein, TNF-alpha, body weight, BMI and waist did not change significantly. Systolic BP MD -2.12 mmHg; diastolic +0.32 mmHg (ns); FMD +0.94% (ns); CRP 0.00 mg/L (ns); TNF-alpha -0.09 pg/mL (ns); weight +0.09 kg (ns); BMI +0.07 (ns); waist +0.77 cm (ns) (Systolic BP -3.65 to -0.59; diastolic -1.37 to 2.02; FMD -0.99 to 2.86; weight -0.38 to 0.69; waist -0.09 to 1.64) Methods, limits and fundingOutcomes: Systolic and diastolic blood pressure, flow-mediated dilation (blood vessel function), C-reactive protein, TNF-alpha, weight, BMI, waist Limitations: The authors call for larger studies. Small average change in a blood-test-style measure; no heart events. Funding and conflicts: Funding is not stated in the abstract. The full paper was not read, so industry links among the authors were not checked. Read: abstract |
| Fantino 2020 Daily consumption of pistachios over 12 weeks improves dietary profile without increasing body weight in healthy women: A randomized controlled intervention. Appetite · PMID 31604062 · DOI |
Randomized controlled trial |
60 women (30 and 30) Healthy pre-menopausal women who did not usually eat nuts |
Pistachios (shelled kernels) eaten as a mid-morning snack Kernel (food) 44 g (about 250 kcal) a day, as studied 12 weeks · vs Women keeping their usual eating |
Weight and body composition did not change in either group. Women eating pistachios ate less of other foods (mostly carbohydrate and starch) and felt less hungry after the snack. Their intake of several fats and minerals (copper, manganese, zinc) and of thiamin and vitamin B6 was higher. Body weight and DXA body composition unchanged; no numbers in the abstract (Not given in the abstract) Methods, limits and fundingOutcomes: Body weight and composition (DXA), appetite, energy and nutrient intake Limitations: Small trial in healthy women, 12 weeks, no blinding possible for a food. Funding and conflicts: Funding is not stated in the abstract (an earlier internal note said a pistachio growers group paid for it; not re-checked from the paper). Treat as possibly industry-funded. Read: abstract |
| Fernández-Rodríguez 2021 The Relationship of Tree Nuts and Peanuts with Adiposity Parameters: A Systematic Review and Network Meta-Analysis. Nutrients · PMID 34208812 · DOI |
Network meta analysis |
105 randomised trials (6,768 participants for body weight) Adults |
Tree nuts and peanuts, pistachio among them Kernels (food) Not given in the abstract Not given in the abstract · vs Control diets and other nuts |
Compared with control diets, nuts did not significantly raise any body measure, except hazelnut diets, which raised waist size. Almond diets lowered waist size compared with control and with pistachio, mixed nut and hazelnut diets. No significant increase with nut diets (hazelnut waist excepted); almond versus pistachio: lower waist with almond (Not given in the abstract) Methods, limits and fundingOutcomes: Body weight, BMI, waist circumference, body fat percentage Limitations: Network comparison; the abstract does not give pistachio-only numbers or a certainty rating. Funding and conflicts: The paper declares no conflicts of interest. Read: abstract |
| Flores-Mateo 2013 Nut intake and adiposity: meta-analysis of clinical trials. Am J Clin Nutr · PMID 23595878 · DOI |
Systematic review meta analysis |
33 randomised trials of nuts in general (total participants not given in the abstract) Adults |
Diets enriched with nuts of any kind (not pistachios alone) Kernels (food) Not given in the abstract Not given in the abstract · vs Control diets |
Diets with nuts did not raise body weight, BMI or waist size compared with control diets. Weight WMD -0.47 kg; BMI -0.40 kg/m2; waist -1.25 cm (all not significant) (Weight -1.17 to 0.22; BMI -0.97 to 0.17; waist -2.82 to 0.31) Methods, limits and fundingOutcomes: Body weight, BMI, waist circumference Limitations: Nuts of all kinds together, not pistachios alone. Trials were controlled-feeding studies, so real-life eating may differ. Funding and conflicts: Funding is not stated in the abstract. The abstract lists no conflict statement. Read: abstract |
| Ghanavati 2020 Pistachios and cardiometabolic risk factors: A systematic review and meta-analysis of randomized controlled clinical trials. Complement Ther Med · PMID 32951758 · DOI |
Systematic review meta analysis |
11 randomised trials, 506 participants Adults in 11 trials (mixed health status) |
Whole pistachio kernels eaten as food (pistachio-enriched diets) Kernel (food) Not given in the abstract; the authors say effects of different amounts are unclear Not given in the abstract · vs Control diets |
Pistachio diets lowered fasting blood sugar, two cholesterol ratios, HbA1c, insulin, systolic blood pressure and an oxidative stress marker (MDA). No harmful effect on BMI or blood pressure was seen. Differences between trials were very large for several results. Fasting blood sugar WMD -3.73; TC/HDL -0.46; LDL/HDL -0.24; HbA1c -0.14; insulin -2.43; systolic BP -3.10 mmHg; MDA -0.36 (Blood sugar -6.99 to -0.46 (I2 99%); TC/HDL -0.76 to -0.15 (I2 95%); LDL/HDL -0.38 to -0.11 (I2 96%); HbA1c -0.26 to -0.02 (I2 60%); insulin -4.85 to -0.001 (I2 58%); systolic BP -5.35 to -0.85 (I2 63%)) Methods, limits and fundingOutcomes: Weight, BMI, blood pressure, blood fats, blood sugar, inflammation markers Limitations: Very high heterogeneity (I2 up to 99%). Blood-test outcomes only. The insulin result only just reaches significance (upper limit -0.001). Funding and conflicts: Funding is not stated in the abstract. The abstract lists no conflict statement. Read: abstract |
| Hadi 2023 Effects of pistachios on glycaemic control: a systematic review and meta-analysis of randomised controlled trials. Br J Nutr · PMID 35795961 · DOI |
Systematic review meta analysis |
8 randomised trials (total participants not given in the abstract) Adults at high risk of cardiovascular disease (people with diabetes were few) |
Whole pistachio kernels eaten as food, swapped for other foods with calories matched Kernel (food) Not given in the abstract Not given in the abstract · vs Control diets |
Pistachios eaten in place of other foods lowered fasting blood sugar and insulin. The insulin resistance score did not change. Fasting blood sugar WMD -5.32 mg/dL; insulin WMD -1.86 uIU/mL; HOMA-IR WMD -0.66 (not significant) (Blood sugar -7.80 to -2.64; insulin -3.13 to -0.59; HOMA-IR -1.89 to 0.58) Methods, limits and fundingOutcomes: Fasting blood sugar, fasting insulin, insulin resistance score (HOMA-IR) Limitations: Few trials, small, and few in people with diabetes (the authors say so). The abstract gives no certainty rating. Funding and conflicts: Funding is not stated in the abstract. The abstract lists no conflict statement. Read: abstract |
| Hadi 2023 Consumption of pistachio nuts positively affects lipid profiles: A systematic review and meta-analysis of randomized controlled trials. Crit Rev Food Sci Nutr · PMID 34933637 · DOI |
Systematic review meta analysis |
12 randomised trials (total participants not given in the abstract) Adults |
Whole pistachio kernels eaten as food Kernel (food) Not given in the abstract Not given in the abstract · vs Control diets |
Pistachio eating lowered total cholesterol, LDL and triglycerides on average. HDL did not change significantly. Total cholesterol WMD -7.48 mg/dL; LDL WMD -3.82 mg/dL; triglycerides WMD -11.19 mg/dL; HDL WMD +2.45 mg/dL (not significant) (Total cholesterol -12.62 to -2.34; LDL -5.49 to -2.16; triglycerides -14.21 to -8.17; HDL -2.44 to 7.33) Methods, limits and fundingOutcomes: Total cholesterol, LDL, HDL and triglycerides Limitations: The authors say larger studies are needed. Blood-test outcomes, not heart events. No certainty rating in the abstract. Funding and conflicts: Funding is not stated in the abstract. The abstract lists no conflict statement. Read: abstract |
| Jeong 2025 Update on Tree Nut and Seed Allergies: Prevalence, Clinical Characteristics, Diagnosis, and Management. Allergy Asthma Immunol Res · PMID 41330701 · DOI |
Narrative review |
Not applicable People with tree nut and seed allergy |
Tree nuts and seeds (allergy) |
Tree nut and seed allergies are often severe, usually start in childhood and may last for life. Many people are sensitised to several tree nuts but fewer react to more than one. The biggest overlaps in actual reactions are reported between cashew and pistachio and between walnut and pecan. First-line treatment for anaphylaxis is epinephrine given into the muscle. Highest clinical overlap: cashew-pistachio and walnut-pecan (Not applicable) Methods, limits and fundingOutcomes: Prevalence, severity, co-allergy, diagnosis and management Limitations: Narrative review, 2025. Funding and conflicts: The paper record states that there are no financial or other issues that might lead to a conflict of interest. Read: abstract |
| Lazzarin 2025 Nut consumption in chronic kidney disease: a systematic review. Front Nutr · PMID 41293182 · DOI |
Systematic review |
4 studies (3 trials, 1 cohort), 1,270 people with chronic kidney disease People with chronic kidney disease |
Nuts of several kinds (Brazil nuts, baru almond oil, walnuts, total nuts), not pistachios Kernels (food) and oil Not given in the abstract Not given in the abstract · vs Not given in the abstract |
In four studies at moderate-to-high risk of bias, Brazil nuts and baru almond oil improved some oxidative stress and inflammation markers, and walnuts lowered LDL and blood pressure without upsetting blood electrolytes. Total nut intake was linked to fewer deaths from any cause in one cohort. Pistachios were not singled out in the abstract. Not given (Not given) Methods, limits and fundingOutcomes: Blood fats, inflammation, oxidative stress, blood pressure, death from any cause Limitations: Four heterogeneous studies, all at moderate-to-high risk of bias; pistachios not studied alone. Funding and conflicts: No commercial or financial conflict declared; one author is a Frontiers editorial board member. Read: abstract |
| Liu 2020 Comparative effects of different types of tree nut consumption on blood lipids: a network meta-analysis of clinical trials. Am J Clin Nutr · PMID 31773150 · DOI |
Network meta analysis |
34 randomised trials, 1,677 participants Adults in trials comparing nut-enriched diets (walnut, pistachio, hazelnut, cashew, almond) with control diets |
Tree-nut-enriched diets, pistachio among them Kernel (food) Not given in the abstract Not given in the abstract · vs Control diets and other nuts |
A pistachio-enriched diet ranked best for triglycerides, LDL and total cholesterol (SUCRA 85%, 87% and 96%), with walnut second for triglycerides and total cholesterol and almond second for LDL. Pistachio and walnut diets beat control diets. The authors rate the evidence quality low and say the trials were few, small and poorly reported. SUCRA rankings: triglycerides 85%, LDL 87%, total cholesterol 96% (pistachio) (Not given in the abstract) Methods, limits and fundingOutcomes: Triglycerides, LDL, total cholesterol, HDL Limitations: Evidence rated low quality by the authors. A ranking does not prove one nut is better than another. Funding and conflicts: Funding is not stated in the abstract. The abstract lists no conflict statement. Read: abstract |
| Smeekens 2018 Tree nut allergies: Allergen homology, cross-reactivity, and implications for therapy. Clin Exp Allergy · PMID 29700869 · DOI |
Narrative review |
Not applicable People with tree nut allergy |
Tree nuts, pistachio among them (allergy) |
Tree nut allergy affects about 1% of people in the United States, is outgrown in under 10% of cases, and can be life-threatening. Because tree nuts often cross-react, the current guideline is strict avoidance of all tree nuts once one allergy is diagnosed. Cashew and pistachio are named as highly cross-reactive. No large trials of treatment exist for tree nut allergy. About 1% prevalence in the US; outgrown in under 10% (Not applicable) Methods, limits and fundingOutcomes: Tree nut allergy frequency, cross-reactivity, treatment Limitations: Narrative review, 2018, not a systematic search. Funding and conflicts: The abstract lists no conflict statement. Read: abstract |
| Soares Mateus 2021 Mycotoxins in Pistachios (Pistacia vera L.): Methods for Determination, Occurrence, Decontamination. Toxins (Basel) · PMID 34678975 · DOI |
Narrative review |
Not applicable Pistachio samples from published studies |
Mycotoxins in pistachios (contamination) Kernel |
Aflatoxins are the most common and most toxic-to-humans mycotoxins found in pistachios, with liver-damaging effects. Other mycotoxins (ochratoxin A, fumonisins, zearalenone and others) have also been found in nuts. The authors say prevention before harvest is the most effective control, and that contamination is sporadic. Not applicable (Not applicable) Methods, limits and fundingOutcomes: Which mycotoxins occur in pistachios and how they are measured and reduced Limitations: Review of analytical methods and occurrence studies; reported levels vary by study. Funding and conflicts: The abstract lists no conflict statement. Read: abstract and full text (PMC) |
| s-fda-allergens US FDA: Food Allergies · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text | ||
| s-gbif-pistacia-vera GBIF Backbone Taxonomy: Pistacia vera L. · Source |
Taxonomy database n/a |
Methods, limits and fundingRead: full-text | ||
| s-medlineplus-foodallergy MedlinePlus (US National Library of Medicine): Food allergy · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text | ||
| s-nhs-young-children NHS: Foods to avoid giving babies and young children · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text | ||
| s-nkf-nuts-seeds National Kidney Foundation: Nuts and Seeds · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text | ||
| s-usda-fdc-170184 USDA FoodData Central: Nuts, pistachio nuts, raw (FDC 170184, SR Legacy, April 2018) · Source |
Reference database n/a |
Methods, limits and fundingRead: full-text | ||
| s-who-mycotoxins World Health Organization: Mycotoxins (fact sheet) · Source |
Health agency n/a |
Methods, limits and fundingRead: full-text |
What we do not know yet
- No trial read measured heart attacks, strokes, diabetes or death with pistachios; all results are blood tests.
- The abstracts give no formal certainty rating, and the reviews were searched up to 2019 and may pool some of the same trials.
- No study compared raw with roasted or salted, or in-shell with shelled pistachios, and no extract, oil or supplement was tested.
- No pistachio-specific pregnancy or breastfeeding advice, drug-interaction database search, or heavy metal, pesticide, oxalate or FODMAP data was read.
- The funding of the 12-week women's trial is not stated in the abstract, and the full papers were not read.
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 5
HbA1c
Lowered in trials
A blood test that reflects average blood sugar over the past two to three months.
Low certaintyResults and what it means
Why it was measured
It is the usual long-term marker of blood sugar control.
Statistical vs. clinical meaning
A very small average change from one meta-analysis.
Safety implication
None specific.
| Study | Result | People | Product |
|---|---|---|---|
| 5 | -0.14 (95% CI -0.26 to -0.02); I2 60% | 11 trials, 506 adults | Pistachio-enriched diets |
LDL cholesterol
Lowered in trials
The "bad" cholesterol carried in the blood. Higher levels are linked to more heart disease.
Low certaintyResults 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 average fall. A first-place ranking is not proof that pistachios beat other nuts.
Safety implication
None specific.
Triglycerides
Lowered in trials
A type of fat carried in the blood.
Low certaintyResults and what it means
Why it was measured
High levels are linked to heart risk.
Statistical vs. clinical meaning
A small average fall.
Safety implication
None specific.
HDL cholesterol
No clear change in trials
The "good" cholesterol that helps carry fat away from blood vessels.
Low certaintyBody weight
No clear change in trials
How much a person weighs, measured in kilograms.
Moderate certaintyResults and what it means
Why it was measured
It is the main check on whether a calorie-dense food adds weight.
Statistical vs. clinical meaning
No weight gain in pooled trials.
Safety implication
None specific.
| Study | Result | People | Product |
|---|---|---|---|
| 1 | +0.09 kg (95% CI -0.38 to 0.69), not significant | 13 trials, 563 adults | Pistachio eating |
| 4 | -0.47 kg (95% CI -1.17 to 0.22), not significant | 33 trials of nuts in general | Nut-enriched diets |
| 2 | Unchanged in both groups; no numbers in the abstract | 60 healthy pre-menopausal women | Pistachio snack, 12 weeks |
Other 7
Fasting blood sugar
Lowered in trials
The sugar level in blood after not eating overnight.
Low certaintyResults and what it means
Why it was measured
It is the standard first marker of how well the body handles sugar.
Statistical vs. clinical meaning
A small average fall in short trials with very large differences between trials.
Safety implication
None specific. Do not change diabetes medicine without your clinician.
Fasting insulin
Lowered in trials
The insulin level in blood after not eating overnight; higher levels can mean the body needs more insulin to control sugar.
Low certaintyResults and what it means
Why it was measured
It is used to judge insulin resistance.
Statistical vs. clinical meaning
Lower insulin, but the insulin resistance score did not change.
Safety implication
None specific.
Systolic blood pressure
Lowered in trials
The top number in a blood pressure reading, the pressure when the heart beats.
Low certaintyResults and what it means
Why it was measured
High blood pressure raises the risk of stroke and heart disease.
Statistical vs. clinical meaning
A small average change; the two reviews may pool some of the same trials.
Safety implication
Do not stop blood pressure medicine because of this finding.
Diastolic blood pressure
No clear change in trials
The bottom number in a blood pressure reading, the pressure between beats.
Low certaintyWaist circumference
No clear change in trials
The distance around the waist, used as a rough marker of belly fat.
Low certaintyResults and what it means
Why it was measured
Belly fat is linked to metabolic and heart risk.
Statistical vs. clinical meaning
No clear change with pistachios.
Safety implication
None specific.
| Study | Result | People | Product |
|---|---|---|---|
| 1 | +0.77 cm (95% CI -0.09 to 1.64), not significant | 13 trials, 563 adults | Pistachio eating |
| 3 | Almond diets lowered waist size compared with control and with pistachio diets; no significant waist rise with pistachio versus control reported in the abstract | 105 trials | Tree nut and peanut diets compared |
C-reactive protein
No clear change in trials
A blood marker of inflammation in the body.
Low certaintyFlow-mediated dilation
No clear change in trials
An ultrasound test of how well an artery widens when blood flow rises; a measure of blood vessel function.
Low certaintySafety
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
- Tree nut allergy comes first. The US FDA lists tree nuts among the nine major food allergens, and MedlinePlus lists tree nuts among common food allergies in people of all ages. Pistachio is a tree nut. A 2018 review says tree nut allergy affects about 1% of people in the US, is outgrown in under 10% of cases and can be life-threatening. Reactions range from itching and hives to anaphylaxis. If you are allergic to pistachios or to another tree nut, ask an allergist before eating them. Authoritative guidance 13 15 11
- Cashew and pistachio often go together. A 2025 review reports that people with a tree nut allergy are often sensitised to several nuts, but fewer react to more than one. The biggest overlaps in real reactions are cashew with pistachio and walnut with pecan. A 2018 review says the current guideline is to avoid all tree nuts once one allergy is diagnosed, because how far cross-reaction goes is unclear for other nuts. An allergist can say what is safe for you. Review 8 11
- Mouldy nuts can carry aflatoxin. WHO names pistachio among nuts regularly contaminated with aflatoxins, poisons made by moulds. Large doses can cause acute poisoning that can be life-threatening, usually through liver damage, and WHO says there is evidence that aflatoxins can cause liver cancer in humans. A 2021 review calls aflatoxins the most common and most toxic mycotoxins in pistachios. WHO advises checking nuts for mould and throwing away any that look mouldy, discoloured or shrivelled. Authoritative guidance 19 12
- Whole nuts can choke young children. The NHS says whole nuts should not be given to children under 5 because they can choke on them. Nuts can be given from the start of weaning if they are crushed or ground and added to food. Ask your child's doctor or health visitor about introducing nuts and about allergy. Authoritative guidance 16
- Kidney disease and dialysis. USDA lists 1,025 mg of potassium and 490 mg of phosphorus per 100 g of raw pistachios. The National Kidney Foundation says most people with chronic kidney disease or a kidney transplant do not have to limit nuts and seeds, but for people on hemodialysis three times a week potassium and phosphorus can be a concern and it advises limiting nuts to a quarter-cup portion. A kidney dietitian can tell you what applies to you. Authoritative guidance 17 18 9
Side effects 4
| Effect | How often | Severity and recovery | Evidence |
|---|---|---|---|
| Allergic reactions to pistachio, from mouth itching and hives to anaphylaxis Prevalence is for tree nuts as a group, not pistachio alone. | Tree nut allergy affects about 1% of people in the US (2018 review). No pistachio-only rate was read. | can be severe (anaphylaxis) Tree nut allergy is outgrown in under 10% of cases (2018 review). | Review 11 15 13 |
| Choking in young children NHS names whole nuts for children under 5. | No frequency was found. | can be life-threatening Not applicable. | Authoritative guidance 16 |
| Aflatoxin exposure from mouldy or poorly stored nuts This is about spoiled nuts, not normal fresh nuts, and WHO's advice is to discard mouldy ones. | No pistachio-specific frequency was read. A 2021 review says contamination is sporadic. | large doses can cause acute poisoning and liver damage; long exposure is linked to liver cancer Not described in the sources read. | Authoritative guidance 19 12 |
| Digestive upset (for example gas or bloating) No source read for this page describes digestive side effects of pistachios, so none is claimed. | Not found. | Not found. Not found. | None found |
Liver
No liver injury from eating normal fresh pistachios was found in the sources read. Aflatoxin from mouldy nuts can damage the liver; see the contamination section. A liver-safety source (such as LiverTox) was not searched for pistachios. 19 12
How often. No frequency was found.
Monitoring. No agency monitoring advice was found.
This is a safety connection. It is not evidence that Pistachios supports liver health.
Medicines and supplements 3
| With | Why it matters | Importance | Evidence | What to do |
|---|---|---|---|---|
| Blood pressure medicines prescription | Trials found a small average fall in systolic pressure of about 2 to 3 mmHg with pistachio-enriched diets. No interaction mechanism was read. | No interaction with blood pressure medicine was described in the sources read. This entry is a precaution based on the trial result, not a reported interaction. | Theoretical Very low certainty 5 1 | Keep taking your medicine and tell your doctor if you change your diet a lot; ask a pharmacist if unsure. |
| Diabetes medicines and insulin prescription | Trials found a small average fall in fasting blood sugar and insulin with pistachio-enriched diets. No interaction mechanism was read. | No interaction with diabetes medicine was described in the sources read. This entry is a precaution based on the trial result, not a reported interaction. | Theoretical Very low certainty 6 5 | Keep taking your medicine and ask your diabetes team or pharmacist before large diet changes. |
| Any other medicine prescription | Not described. | No sources read describe an interaction between pistachios eaten as food and a medicine, and none was searched for beyond this page's sources (for example a drug-interaction database). | None found Not enough evidence | Ask a pharmacist about your own medicines. |
Who should check first 6
| Situation | Advice | Evidence |
|---|---|---|
| Known or suspected allergy to pistachio or another tree nut | Avoid pistachios and read labels, and ask an allergist about your own case. For trouble breathing, wheezing or swelling of the face, lips or throat, use epinephrine if prescribed and call 911 or your local emergency number. | Authoritative guidance 13 15 11 8 |
| Allergy to cashew (or walnut or pecan) | Cashew-pistachio is the most often reported co-allergy pair. Ask an allergist before eating pistachios. | Review 8 11 |
| Children under 5 | The NHS says not to give whole nuts; crushed or ground nuts added to food are suggested for babies starting solid food. Ask your child's doctor about allergy and nut introduction. | Authoritative guidance 16 |
| On hemodialysis | Potassium and phosphorus in nuts can be a concern; the National Kidney Foundation advises limiting nuts to a quarter-cup portion. Ask your kidney dietitian. | Authoritative guidance 17 18 |
| Pregnancy or breastfeeding | The sources read do not single out pistachios for pregnancy or breastfeeding, and no pistachio-specific official statement was found. If you are not allergic, ordinary food amounts are not flagged by the sources read. Ask your midwife, doctor or dietitian about your own diet. | None found |
| Nuts that look mouldy, discoloured or shrivelled | WHO advises throwing them away. | Authoritative guidance 19 |
Overdose, product quality and regulators
Summary. No toxicity from fresh pistachios eaten as food was found in the sources read. The safety points are allergy, choking in young children and mould (aflatoxin) in spoiled nuts.
Animal. Not reviewed.
High dose or long term signals. Not found for pistachios. The NKF kidney advice is about people on dialysis, not general toxicity.
Overdose response. Not found.
Genotoxicity. Not researched for pistachios. WHO says aflatoxins damage DNA and cause cancer in animals.
Aflatoxins are the main contaminant described in the sources read. Heavy metals, pesticides and other contaminants were not researched.
Aflatoxins and mould. WHO lists pistachio among tree nuts regularly contaminated with aflatoxins. A 2021 review calls aflatoxins the most common and most toxic mycotoxins in pistachios and says prevention before harvest is the most effective control. WHO says mould usually does not grow in properly dried and stored food. 19 12
Other mycotoxins. The 2021 review also names ochratoxin A, fumonisins, zearalenone and others as mycotoxins that have been involved in nuts. Levels vary by study. 12
| Body | Action | Date |
|---|---|---|
| US FDA (United States) | Food Allergies: tree nuts are one of nine major food allergens (milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soybeans, sesame). The part read does not name pistachio. source | 2026-03-11 |
| MedlinePlus (US National Library of Medicine) (United States) | Food allergy: tree nuts are among the most common food allergies, in people of all ages; allergies to peanuts, tree nuts and shellfish tend to last a lifetime. source | 2024-10-29 |
| World Health Organization (International) | Mycotoxins fact sheet: pistachio is among nuts regularly contaminated with aflatoxins; inspect nuts and discard any that look mouldy, discoloured or shrivelled. source | 2023-10-02 |
| NHS (United Kingdom) | Foods to avoid giving babies and young children: whole nuts should not be given to children under 5; crushed or ground nuts can be added to food from the start of weaning. source | 2026-02-18 |
| National Kidney Foundation (United States) | Nuts and Seeds: most people with chronic kidney disease or a transplant do not have to limit nuts for potassium or phosphorus; on hemodialysis, limit to a quarter-cup portion; a kidney dietitian decides. source |
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 pistachios or another tree nut (possible anaphylaxis): use epinephrine if prescribed, then call 911 or your local emergency number
- A child who is choking on a nut or shell: follow first aid training and call 911 or your local emergency number
- Feeling seriously unwell after eating nuts that were mouldy (for example repeated vomiting or yellow skin or eyes): seek 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 are pistachios?
Do pistachios lower blood sugar?
A little, on average, in short trials. In 8 trials of people at high cardiovascular risk, pistachios eaten in place of other foods lowered fasting blood sugar by 5.32 mg/dL and insulin by 1.86 uIU/mL; the insulin resistance score did not change. Few trials were in people with diabetes, and these are blood-test changes only.
Do pistachios lower cholesterol?
Do pistachios lower blood pressure?
Do pistachios make you gain weight?
Not in the pooled trials read. A pistachio meta-analysis, a 33-trial nut meta-analysis and a 105-trial network meta-analysis found no significant gain in weight, BMI or waist (hazelnut diets raised waist size). Nuts are calorie-dense, 560 kcal per 100 g by USDA, and these results do not show that pistachios help with weight loss.
Are pistachios better than other nuts?
One comparison ranked pistachio first for LDL, triglycerides and total cholesterol across 34 trials, with walnut and almond next. The authors rate the evidence low quality, so it does not show that pistachios beat other nuts.
If I am allergic to cashews, can I eat pistachios?
Are pistachios safe for young children?
The NHS says whole nuts should not be given to children under 5 because of choking; crushed or ground nuts can be added to food. Ask your child's doctor about introducing nuts and about allergy.
Can mouldy pistachios be harmful?
Can people with kidney disease eat pistachios?
Do pistachios interact with medicines?
No interaction between pistachios eaten as food and a medicine was found in the sources read, but no drug-interaction database was searched. Pistachios lowered blood pressure and blood sugar slightly on average in trials, so tell your doctor or pharmacist if you take medicines for these and change your diet a lot.
Are pistachios safe in pregnancy and breastfeeding?
No pistachio-specific advice was found in the sources read. If you are not allergic, none of the sources read singles out pistachios eaten as food. Ask your midwife, doctor or dietitian about your own diet.
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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 pistachio page and nutrient summary, re-read USDA FoodData Central values from a saved copy of the data, read the health agency pages (FDA, MedlinePlus, WHO, NHS, National Kidney Foundation) and re-read PubMed abstracts for the reviews and the trial. Only abstracts were read for PubMed studies, plus the full text of one mycotoxin review. 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. The funding of the one pistachio trial cited is not stated in its abstract.
Sources 19
Each source was opened and checked. Where we read only the abstract, it says so. The small numbers in the text point here.
- Asbaghi O, Hadi A, Campbell MS, Venkatakrishnan K, Ghaedi E. Effects of pistachios on anthropometric indices, inflammatory markers, endothelial function and blood pressure in adults: a systematic review and meta-analysis of randomised controlled trials.. Br J Nutr. 2021. PMID 33198823. DOI 10.1017/S0007114520004523. (abstract)
- Fantino M, Bichard C, Mistretta F, Bellisle F. Daily consumption of pistachios over 12 weeks improves dietary profile without increasing body weight in healthy women: A randomized controlled intervention.. Appetite. 2020. PMID 31604062. DOI 10.1016/j.appet.2019.104483. (abstract)
- Fernández-Rodríguez R, Mesas AE, Garrido-Miguel M, Martínez-Ortega IA, et al.. The Relationship of Tree Nuts and Peanuts with Adiposity Parameters: A Systematic Review and Network Meta-Analysis.. Nutrients. 2021. PMID 34208812. DOI 10.3390/nu13072251. (abstract)
- Flores-Mateo G, Rojas-Rueda D, Basora J, Ros E, Salas-Salvadó J. Nut intake and adiposity: meta-analysis of clinical trials.. Am J Clin Nutr. 2013. PMID 23595878. DOI 10.3945/ajcn.111.031484. (abstract)
- Ghanavati M, Rahmani J, Clark CCT, Hosseinabadi SM, Rahimlou M. Pistachios and cardiometabolic risk factors: A systematic review and meta-analysis of randomized controlled clinical trials.. Complement Ther Med. 2020. PMID 32951758. DOI 10.1016/j.ctim.2020.102513. (abstract)
- Hadi A, Asbaghi O, Kazemi M, Khadem Haghighian H, Ghaedi E. Effects of pistachios on glycaemic control: a systematic review and meta-analysis of randomised controlled trials.. Br J Nutr. 2023. PMID 35795961. DOI 10.1017/S0007114522002100. (abstract)
- Hadi A, Asbaghi O, Kazemi M, Haghighian HK, et al.. Consumption of pistachio nuts positively affects lipid profiles: A systematic review and meta-analysis of randomized controlled trials.. Crit Rev Food Sci Nutr. 2023. PMID 34933637. DOI 10.1080/10408398.2021.2018569. (abstract)
- Jeong K, Lee S. Update on Tree Nut and Seed Allergies: Prevalence, Clinical Characteristics, Diagnosis, and Management.. Allergy Asthma Immunol Res. 2025. PMID 41330701. DOI 10.4168/aair.2025.17.6.672. (abstract)
- Lazzarin T, Ballarin RS, Azevedo PS, Cardoso BR, Minicucci MF. Nut consumption in chronic kidney disease: a systematic review.. Front Nutr. 2025. PMID 41293182. DOI 10.3389/fnut.2025.1659516. (abstract)
- Liu K, Hui S, Wang B, Kaliannan K, et al.. Comparative effects of different types of tree nut consumption on blood lipids: a network meta-analysis of clinical trials.. Am J Clin Nutr. 2020. PMID 31773150. DOI 10.1093/ajcn/nqz280. (abstract)
- Smeekens JM, Bagley K, Kulis M. Tree nut allergies: Allergen homology, cross-reactivity, and implications for therapy.. Clin Exp Allergy. 2018. PMID 29700869. DOI 10.1111/cea.13163. (abstract)
- Soares Mateus AR, Barros S, Pena A, Sanches Silva A. Mycotoxins in Pistachios (Pistacia vera L.): Methods for Determination, Occurrence, Decontamination.. Toxins (Basel). 2021. PMID 34678975. DOI 10.3390/toxins13100682. (abstract and full text (PMC))
- . US FDA: Food Allergies. . . (full-text)
- . GBIF Backbone Taxonomy: Pistacia vera L.. . . (full-text)
- . MedlinePlus (US National Library of Medicine): Food allergy. . . (full-text)
- . NHS: Foods to avoid giving babies and young children. . . (full-text)
- . National Kidney Foundation: Nuts and Seeds. . . (full-text)
- . USDA FoodData Central: Nuts, pistachio nuts, raw (FDC 170184, SR Legacy, April 2018). . . (full-text)
- . World Health Organization: Mycotoxins (fact sheet). . . (full-text)
