MVIIIHealth The MVIII app
← Back

Research · Food and drink

Legumes

Pooled trials found beans, lentils, chickpeas and peas lowered LDL cholesterol by about 7 mg/dL, systolic pressure by about 2 mmHg, body weight by 0.34 kg and fasting glucose slightly. Cohorts link legumes to 6% lower death but not to less type 2 diabetes. About a third of people reported more gas in the first week.

Add to Bio HackChecked 2026-11-13
Status
A food, not a regulated health product. The Dietary Guidelines for Americans, 2025-2030 list beans, peas, lentils and legumes among the plant-sourced protein foods to eat as part of a variety of protein foods [1].
Also called
beans, pulses, lentils, chickpeas, garbanzo beans, peas, dried peas, split peas, black beans, kidney beans, pinto beans, navy beans, baked beans, black-eyed peas, fava beans, broad beans, hummus, dal
Studied for
cholesterol, LDL, blood sugar, type 2 diabetes, weight loss, heart health, blood pressure, longer life, protein, fiber

Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on

Shown to help5

Reported risks3

What it was studied for, and what was found

Shown to help5

Strong

LDL cholesterol

Shown to lower LDL cholesterol by about 7 mg/dL in pooled trials of about one daily serving, against diets without legumes. ApoB and non-HDL cholesterol did not change.

Compared with isocaloric diets without dietary pulses [2]; control diets the abstracts do not describe [3][4]

The numbers and sources
Effect
Diets with a median 130 g a day of pulses, about one serving, lowered LDL cholesterol by 0.17 mmol/L (about 6.6 mg/dL, 95% CI -0.25 to -0.09 mmol/L). ApoB and non-HDL cholesterol did not change [2]. In trials of non-soy legumes, total cholesterol fell 11.8 mg/dL (95% CI -16.1 to -7.5) and LDL 8.0 mg/dL (95% CI -11.4 to -4.6) [3]. A third review found total cholesterol fell 0.22 mmol/L and LDL 0.19 mmol/L [4].
Population
1,037 participants in 26 randomized trials of at least 3 weeks [2]. 268 participants in 10 randomized trials of at least 3 weeks [3]. 448 participants in 14 crossover trials, plus one parallel and one non-randomized trial [4].
Sources
[2], [3], [4]
Caveats
Short trials. The authors of the largest review call for longer and higher-quality trials [2]. The third review included soybeans and found moderate heterogeneity for LDL (I² 52%) [4]. Soy has its own page.
Moderate

Blood sugar in trials

Shown to lower fasting glucose by 0.19 mmol/L in pooled trials. In type 2 diabetes, a legume diet lowered HbA1c 0.2 points more than a wheat fiber diet.

Compared with control diets the abstracts do not describe [5][4]; a high wheat fiber diet [6]

The numbers and sources
Effect
Pulses alone lowered fasting glucose (SMD -0.82, 95% CI -1.36 to -0.27) and fasting insulin (SMD -0.49, 95% CI -0.93 to -0.04) in 11 trials. Pulses within low glycemic index or high-fiber diets lowered glycated proteins, measured as HbA1c or fructosamine [5]. A later review found fasting glucose fell 0.19 mmol/L and HOMA-IR 0.30 [4]. In type 2 diabetes, a low glycemic index diet adding at least 1 cup of legumes a day lowered HbA1c by 0.5% (95% CI -0.6 to -0.4) over 3 months, against 0.3% on a high wheat fiber diet, a difference of 0.2% (95% CI -0.3 to -0.1) [6].
Population
41 trials of at least 7 days in people with and without diabetes [5]. 14 crossover trials and one parallel trial [4]. 121 adults with type 2 diabetes [6].
Sources
[5], [4], [6]
Caveats
Heterogeneity was high and largely unexplained (I² above 75% for glucose markers in the later review) [4][5]. Results are standardized mean differences, which are hard to turn into units [5].
Moderate

Body weight

Shown to lower body weight by 0.34 kg over a median 6 weeks in pooled trials of about one daily serving, against diets without pulses.

Compared with comparator diets without a dietary pulse intervention [7]; the lowest intake category [8]

The numbers and sources
Effect
Diets with a median 132 g a day of pulses lowered weight by 0.34 kg (95% CI -0.63 to -0.04), in both weight-loss and weight-maintaining diets, with low heterogeneity. Six trials suggested lower body fat percentage [7]. In cohorts, the highest legume intake was linked to 13% lower obesity incidence (RR 0.87, 95% CI 0.81 to 0.94), at very low certainty [8].
Population
940 participants in 21 randomized trials of at least 3 weeks [7]. Prospective cohorts with 8,125 obesity cases [8].
Sources
[7], [8]
Caveats
A small effect over short trials. The authors note long-term effects are unknown [7].
Moderate

Blood pressure

Shown to lower systolic pressure by 2.25 mmHg in pooled trials where pulses replaced other foods with the same calories. Diastolic pressure did not change significantly.

Compared with isocaloric diets in which other foods took the place of pulses [9]; a high wheat fiber diet [6]; the lowest intake category [8]

The numbers and sources
Effect
Systolic pressure fell 2.25 mmHg (95% CI -4.22 to -0.28) and mean arterial pressure 0.75 mmHg, and diastolic pressure changed by -0.71 mmHg (95% CI -1.74 to 0.31), not significant [9]. In type 2 diabetes, systolic pressure fell 4.5 mmHg more on a legume diet than a wheat fiber diet [6]. In cohorts, the highest intake was linked to 9% lower hypertension (RR 0.91, 95% CI 0.86 to 0.97), at very low certainty [8].
Population
554 people with and without hypertension in 8 trials of at least 3 weeks [9]. 121 adults with type 2 diabetes [6]. Cohorts with 83,284 hypertension cases [8].
Sources
[9], [6], [8]
Caveats
Heterogeneity was significant for all outcomes, and the authors call for larger trials [9].
Moderate

Death from any cause

Linked to 6% lower death from any cause at the highest legume intake than the lowest, and per extra 50 g a day, in pooled cohorts.

Compared with the lowest intake category, and 50 g a day less in a dose-response model [10]

The numbers and sources
Effect
Higher intake was linked to lower death from any cause (HR 0.94, 95% CI 0.91 to 0.98) and from stroke (HR 0.91, 95% CI 0.84 to 0.99), and not to cardiovascular, coronary or cancer death. Each extra 50 g a day was linked to 6% lower death from any cause (HR 0.94, 95% CI 0.89 to 0.99) [10].
Population
1,141,793 participants and 93,373 deaths in 32 cohorts [10].
Sources
[10]
Caveats
Observational. The authors judged the certainty low to moderate [10].

Mixed results1

Moderate

Heart disease and stroke

Mixed results: one pooled analysis linked legumes to 8% lower cardiovascular disease at low certainty, while another found no link with heart disease or stroke.

Compared with the lowest intake category [8][4][10]

The numbers and sources
Effect
At the highest against the lowest intake, legumes were linked to lower cardiovascular disease (RR 0.92, 95% CI 0.85 to 0.99) and coronary heart disease (RR 0.90, 95% CI 0.83 to 0.99), and not to heart attack, stroke, or cardiovascular, coronary or stroke death [8]. A second review found results suggesting no link with cardiovascular disease, coronary heart disease or stroke [4]. A third found no link with cardiovascular or coronary death, and 9% lower stroke death (HR 0.91, 95% CI 0.84 to 0.99) [10].
Population
28 prospective cohorts [8]. 31 cohorts with 2,081,432 participants who ate generally few legumes [4]. 32 cohorts [10].
Sources
[8], [4], [10]
Caveats
Observational. Certainty was graded low for cardiovascular disease and very low for the other outcomes [8]. Confounding by other diet and lifestyle habits and reverse causation apply.

Not shown to help1

Strong

Type 2 diabetes

Not linked to lower type 2 diabetes in two pooled analyses of cohorts, where most people ate few legumes.

Compared with the lowest intake category [8][4]

The numbers and sources
Effect
Legume intake was not associated with diabetes incidence in an umbrella review and updated meta-analysis [8]. A second review found results suggesting no link with type 2 diabetes and rated the evidence "limited, no conclusion" [4].
Population
Cohorts with 10,457 diabetes cases [8]. 31 cohorts with 2,081,432 participants [4].
Sources
[8], [4]
Caveats
Observational, in populations with low legume intake [4]. The glucose changes in trials are reported above.

Amounts studied

Trials gave a median 130 g of pulses a day, about one serving, for at least 3 weeks [2], or 132 g a day for a median 6 weeks [7]. The flatulence studies used half a cup a day for 8 or 12 weeks [11]. The diabetes trial asked for at least 1 extra cup of legumes a day for 3 months [6]. Cohort reviews modeled death per 50 g a day [10]. The Dietary Guidelines list beans, peas and lentils among protein foods [1].

Risks

Reported risks3

LimitedVery common

Gas and bloating

In two crossover trials, 35% of people eating half a cup of beans a day reported more gas in the first week, falling to 3% by week 8.

The numbers and sources
How common
Very common: more than 1 in 10 people.
Effect
In the first week, increased flatulence was reported by 50% eating pinto beans, 47% eating vegetarian baked beans and 19% eating black-eyed peas, against 3% on a canned carrot control. By week 2 it was 6%, 24% and 12%, and by week 8 3% of bean eaters overall. Between 3% and 11% reported more gas on control diets with no gas-producing foods [11].
Population
46 adults in two crossover trials of 8-week phases and 80 in a 12-week parallel trial, mean age 42, almost all white [11].
Sources
[11]
Caveats
Self-reported symptoms in small trials designed for heart outcomes. Responses varied by bean type [11].
LimitedHow often is not known

Red kidney bean poisoning from undercooked beans

Case reports: UK records list 50 suspected outbreaks of nausea, vomiting and diarrhea within hours of eating raw or undercooked red kidney beans from 1976 to 1989.

The numbers and sources
How common
How often is not known: the sources give no rate.
Effect
Of 50 suspected incidents, 9 were confirmed by finding haemagglutinin, a lectin, in the beans, and 23 more were diagnosed from symptoms, onset 1 to 7 hours after eating, and how the beans were prepared. In many outbreaks the beans were eaten raw or after inadequate heating. The authors report the lectin is inactivated by thorough cooking of well-soaked beans [12].
Population
Incidents reported in the UK, 1976 to 1989 [12].
Sources
[12]
Caveats
Outbreak reports with no count of people exposed.
LimitedHow often is not known

Favism in G6PD deficiency

Case series: in people with G6PD deficiency, eating fava beans is the commonest trigger of acute hemolytic anemia, which may be life-threatening, especially in children.

The numbers and sources
How common
How often is not known: the sources give no rate.
Effect
G6PD deficiency, an inherited enzyme defect, is present in more than 400 million people worldwide, and acute hemolytic anemia is one of its most frequent features, usually triggered by an outside agent [13]. In Gaza children with favism, anemia was more severe with the G6PD Mediterranean and Cairo variants than with G6PD A-, and with the Cairo variant mild anemia persisted up to 4 months after recovery [14].
Population
Children with favism in Gaza, compared with 485 adults and 466 newborns from the same population [14]. A review of G6PD deficiency [13].
Sources
[14], [13]
Caveats
Applies to fava beans and to people with G6PD deficiency, not to legumes in general.

Claims tested and not found

  1. That beans cause lasting gas for most people. In two crossover feeding trials, reports of more gas fell from 35% in the first week to 3% by week 8 [11].
  2. That legumes lower ApoB. Pooled trials found no change in ApoB or non-HDL cholesterol [2].
  3. That eating legumes is linked to less type 2 diabetes. Two pooled analyses of cohorts found no link [8][4].

Related

Soy foodsNutsWhite kidney bean extractFiber supplements

Sources

  1. US Department of Agriculture and US Department of Health and Human Services. Dietary Guidelines for Americans, 2025-2030. realfood.gov. 2026. https://cdn.realfood.gov/DGA.pdf
  2. Ha V, Sievenpiper JL, de Souza RJ, et al. Effect of dietary pulse intake on established therapeutic lipid targets for cardiovascular risk reduction: a systematic review and meta-analysis of randomized controlled trials. Canadian Medical Association Journal. 2014. https://doi.org/10.1503/cmaj.131727
  3. Bazzano LA, Thompson AM, Tees MT, et al. Non-soy legume consumption lowers cholesterol levels: a meta-analysis of randomized controlled trials. Nutrition, Metabolism and Cardiovascular Diseases. 2011. https://doi.org/10.1016/j.numecd.2009.08.012
  4. Thorisdottir B, Arnesen EK, Bärebring L, et al. Legume consumption in adults and risk of cardiovascular disease and type 2 diabetes: a systematic review and meta-analysis. Food and Nutrition Research. 2023. https://doi.org/10.29219/fnr.v67.9541
  5. Sievenpiper JL, Kendall CW, Esfahani A, et al. Effect of non-oil-seed pulses on glycaemic control: a systematic review and meta-analysis of randomised controlled experimental trials in people with and without diabetes. Diabetologia. 2009. https://doi.org/10.1007/s00125-009-1395-7
  6. Jenkins DJ, Kendall CW, Augustin LS, et al. Effect of legumes as part of a low glycemic index diet on glycemic control and cardiovascular risk factors in type 2 diabetes mellitus: a randomized controlled trial. Archives of Internal Medicine. 2012. https://doi.org/10.1001/2013.jamainternmed.70
  7. Kim SJ, de Souza RJ, Choo VL, et al. Effects of dietary pulse consumption on body weight: a systematic review and meta-analysis of randomized controlled trials. The American Journal of Clinical Nutrition. 2016. https://doi.org/10.3945/ajcn.115.124677
  8. Viguiliouk E, Glenn AJ, Nishi SK, et al. Associations between Dietary Pulses Alone or with Other Legumes and Cardiometabolic Disease Outcomes: An Umbrella Review and Updated Systematic Review and Meta-analysis of Prospective Cohort Studies. Advances in Nutrition. 2019. https://doi.org/10.1093/advances/nmz113
  9. Jayalath VH, de Souza RJ, Sievenpiper JL, et al. Effect of dietary pulses on blood pressure: a systematic review and meta-analysis of controlled feeding trials. American Journal of Hypertension. 2014. https://doi.org/10.1093/ajh/hpt155
  10. Zargarzadeh N, Mousavi SM, Santos HO, et al. Legume Consumption and Risk of All-Cause and Cause-Specific Mortality: A Systematic Review and Dose-Response Meta-Analysis of Prospective Studies. Advances in Nutrition. 2023. https://doi.org/10.1016/j.advnut.2022.10.009
  11. Winham DM, Hutchins AM. Perceptions of flatulence from bean consumption among adults in 3 feeding studies. Nutrition Journal. 2011. https://doi.org/10.1186/1475-2891-10-128
  12. Rodhouse JC, Haugh CA, Roberts D, Gilbert RJ. Red kidney bean poisoning in the UK: an analysis of 50 suspected incidents between 1976 and 1989. Epidemiology and Infection. 1990. https://doi.org/10.1017/s095026880004810x
  13. Cappellini MD, Fiorelli G. Glucose-6-phosphate dehydrogenase deficiency. The Lancet. 2008. https://doi.org/10.1016/s0140-6736(08)60073-2
  14. Reading NS, Sirdah MM, Shubair ME, et al. Favism, the commonest form of severe hemolytic anemia in Palestinian children, varies in severity with three different variants of G6PD deficiency within the same community. Blood Cells, Molecules, and Diseases. 2016. https://doi.org/10.1016/j.bcmd.2016.07.001

Everything in the library