Beans and lentils: a small real effect, and a portion almost nobody eats

Pulses are the rare cheap food where the randomised trials agree, and the effect they agree on is modest. About 130 g of whole pulses a day for a median of 6 weeks lowered LDL cholesterol by 0.14 mmol/L (95% CI 0.08 to 0.19) across 38 randomised trials in 2095 adults, with GRADE certainty moderate to high. For beans the relationship was linear up to 1 cup a day, each half cup going with 0.25 mmol/L lower LDL (95% CI 0.02 to 0.48), and the line stops at a cup because that is where the trials stop. Most of this is beans. The same authors say trials on chickpeas, dried peas and lentils are still few, so the lentil half of the title rests on less. Weight moves as well, barely: 21 randomised trials in 940 people found 0.34 kg less body weight (95% CI 0.04 to 0.63) over a median of six weeks, and that showed up in diets that were not calorie restricted. Then there is the portion. In a national Israeli survey of 2808 adults the 31.1 percent who ate any legume that day had a median of 40.8 g, about a quarter of a cup, against the 130 g the lipid trials used. In two NHANES cycles the share of US adults eating mature legumes on a given day fell from 12.8 percent to 8.3 percent, and dry beans from 10.0 to 6.5 percent. Both surveys asked about a single day rather than a habit. One condition sits under all of this, and this page has no safety section to put it in. EFSA concluded in 2026 that the lectin risk from beans and lentils comes from inadequate preparation and that soaking and boiling deactivate lectins, and it gives no boiling time and no temperature, so the step that carries the whole finding is the one nobody here defines.

What a real portion looks like

• In a national Israeli survey of 2808 adults, 31.1 percent ate any legume on the recall day. Among those who did, the median intake was 40.8 g a day, and chickpeas led at 67.0 percent against lentils at 14.5 percent. — nationally representative sample of Israeli adults aged 18 to 64, single 24 hour recall (n = 2808) Evidence C source
  31.1 percent consumers, median intake among consumers 40.8 g a day, interquartile range 20.4 to 74.0 g
• In US NHANES data the share of adults eating mature legumes on a given day fell from 12.8 percent in 2011 to 8.3 percent in 2014, and dry beans from 10.0 to 6.5 percent. The authors call anything under 37.5 g a day marginal. — US adults, NHANES 2011-2012 and 2013-2014 cycles, plus a 2017 online survey of Oregon families (n = two NHANES cycles) Evidence C source
  Mature legume consumers 12.8 percent falling to 8.3 percent, dry bean consumers 10.0 percent falling to 6.5 percent

What your body absorbs

• Antinutritional factors in legume protein sources are plant defence compounds that lower plant protein quality by interfering with the bioavailability and absorption of nutrients. — mechanistic account within a systematic review of alternative protein sources Evidence D source
  Direction only, lower protein quality and reduced nutrient bioavailability, no size given
• In 93 German vegans taking no supplements, mean vitamin B6 intake was 2.83 mg a day yet 16 percent had an erythrocyte enzyme activity coefficient above 1.85, and the authors named beans and lentils as foods whose pyridoxine is well absorbed. — 93 German vegans, 50 women, mean age 43.7 years, taking no vitamin supplements (n = 93) Evidence C source
  Mean B6 intake 2.83 mg a day, 16 percent with EAST-AC above 1.85 and a further 58 percent between 1.5 and 1.85

What cooking and storage change

• EFSA concluded in 2026 that the lectin risk from beans and lentils comes from inadequate preparation, and that soaking and boiling deactivate lectins so that they pose no health concern. — general population of the European Union, agency risk assessment Evidence E source
  Acute gastrointestinal illness reported after undercooked beans, no health concern after adequate soaking and boiling
• In an 8 year old with peanut allergy, specific IgE was positive to lentil at 3.12 kU/l alongside lupin, soy and chickpea, and yet boiled legumes were tolerated so only the peanut allergy mattered clinically. — one 8 year old asthmatic child allergic to peanut (n = 1) Evidence C source
  Specific IgE positive to lentil 3.12 kU/l, lupin 1.43 kU/l, soy 2.15 kU/l and chickpea 0.7 kU/l, boiled legumes tolerated

What it does to your health

• Diets containing pulses such as beans and lentils produced a weight reduction of 0.34 kg (95% CI 0.04 to 0.63 kg) against diets without pulses, pooled from 21 randomised trials in 940 people over a median of 6 weeks. — adults in 21 randomised trials of at least 3 weeks, both weight loss and weight maintaining diets (n = 940) Evidence A source
  Body weight mean difference -0.34 kg, 95% CI -0.63 to -0.04 kg, P = 0.03
• About 130 g of whole pulses a day for a median of 6 weeks lowered LDL cholesterol by 0.14 mmol/L (95% CI 0.08 to 0.19 mmol/L) across 38 randomised trials in 2095 people, with GRADE certainty moderate to high. — adults in 38 randomised trials of at least 3 weeks, 52 trial comparisons, median dose 130 g of pulses a day (n = 2095) Evidence A source
  LDL cholesterol mean difference -0.14 mmol/L, 95% CI -0.19 to -0.08, and non-HDL cholesterol -0.22 mmol/L, 95% CI -0.30 to -0.14
• A linear dose-response was found for beans up to 1 cup a day, where each half cup went with 0.25 mmol/L lower LDL cholesterol (95% CI 0.02 to 0.48 mmol/L). — adults in randomised trials of whole pulses, bean subset, dose-response analysis (n = 2095 across all pulse types) Evidence A source
  Coefficient -0.25 mmol/L per 0.5 cup a day, 95% CI -0.48 to -0.02, for LDL cholesterol
• Across three Canadian case-control studies with 617 prostate cancer cases and 636 controls, the highest quartile of beans, lentils and nuts intake carried odds of prostate cancer of 0.69 against the lowest quartile (95% CI 0.53 to 0.91), and these are odds rather than risks. — 617 incident prostate cancer cases and 636 population controls from Ontario, Quebec and British Columbia (n = 1253) Evidence C source
  Odds ratio 0.69, 95% CI 0.53 to 0.91, highest versus lowest quartile of beans, lentils and nuts

What people believe that the data does not support

• A Canadian obstetric practice guideline names beans and lentils among good or excellent food sources of folic acid for women of reproductive age, and still advises a supplement of 0.4 mg to 1.0 mg of folic acid daily for women who could become pregnant. — women of reproductive age in Canada, clinical practice guideline Evidence E source
  Food sources named as good or excellent, recommendation graded III-A, supplement 0.4 to 1.0 mg daily graded II-1A

Who this works differently for

• Among pregnant women living with HIV in Cape Town, eating legumes such as baked beans and lentils on 4 to 7 days a week went with adjusted odds of overweight or obesity of 0.50 (95% CI 0.28 to 0.86) at the first antenatal visit. — 479 pregnant women living with HIV, out of 989 enrolled and followed to delivery in an urban South African community (n = 479 of 989) Evidence C source
  Adjusted odds ratio 0.50, 95% CI 0.28 to 0.86, for overweight or obesity

What is still unknown

• A 2025 systematic review of lentil, faba bean, mung bean and seven other alternative protein sources found antinutritional factors, phytoestrogens and oligosaccharides in every source, allergenic properties in all of them, and no conclusive data to quantify safety after processing. — ten emerging alternative protein sources and their derived protein and food products (n = 10 protein sources reviewed) Evidence C source
  Antinutritional factors, phytoestrogens and oligosaccharides present in all sources, allergenicity present in all, safety after processing not quantifiable
• A systematic review of pulses and the human gut microbiome screened 2444 articles and found only five eligible human studies, whose results on whether pulses change gut microbiota were inconsistent. — human studies of whole pulses and pulse derived fibre, 1990 to February 2019 (n = 5 studies from 2444 articles screened) Evidence A source
  Inconsistent changes in abundance and diversity of gut microbiota, no pooled estimate possible

The bottom line

Cooking is the safety step here, and it is not optional. EFSA concluded in 2026 that the lectin problem with beans and lentils comes from inadequate preparation, that soaking and boiling deactivate lectins so they pose no health concern, and that some human cases of acute gastrointestinal illness have followed undercooked beans. The plain language summary gives no boiling time or temperature, and in the scenario where cooking deactivates only half the lectins EFSA's own margin of exposure falls below the safety threshold, so a proper soak and a real boil carry the whole finding. Allergy on this page rests on one child. An 8 year old with peanut allergy had specific IgE to lentil at 3.12 kU/l, soy at 2.15 and chickpea at 0.7, tolerated boiled legumes, and only the peanut allergy mattered clinically. That is a single case, and it happens to point the reassuring way, which is weaker than a study in allergic children. A 2025 systematic review of lentil, faba bean, mung bean and seven other protein sources found antinutritional factors, phytoestrogens and oligosaccharides in all of them, allergenic properties in all of them, and no conclusive data on safety after processing. Those antinutrients are also why absorption is an open question. The same reviewers describe them as plant defence compounds that lower plant protein quality by interfering with the bioavailability and absorption of nutrients, with no figure attached to a cooked portion of anything. Folate is where the label outruns the food. A Canadian obstetric guideline names beans and lentils among good or excellent food sources of folic acid. It still tells women who could become pregnant to take 0.4 mg to 1.0 mg of folic acid daily as a supplement, a graded position from 2003 that may since have been replaced. Two associations get quoted as though they were effects. Pooling three Canadian case-control studies, the top quartile of beans, lentils and nuts carried odds of prostate cancer of 0.69 against the bottom quartile (95% CI 0.53 to 0.91) among 617 cases and 636 controls. Those are odds rather than risks, the three foods were pooled into one variable, and men recalled their diet after diagnosis. Among 479 pregnant women living with HIV in Cape Town, legumes on 4 to 7 days a week went with adjusted odds of overweight or obesity of 0.50 (95% CI 0.28 to 0.86) at the first antenatal visit. That came from a food frequency questionnaire that measured no quantities, and the association was absent in the women without HIV. Gut bacteria are the loudest claim with the least behind it. A systematic review screened 2444 articles, found five eligible human studies of pulses and the human gut microbiome, and their results did not agree. Ninety three German vegans taking no supplements averaged 2.83 mg of vitamin B6 a day and 16 percent still had an erythrocyte enzyme activity coefficient above 1.85. That is why those authors told vegans to eat beans and lentils, an inference of theirs rather than something they tested. We have no USDA composition record for this pair, which is why the table above is empty, and we found no trial in children and none in kidney disease. Nothing here tested pulses in pregnancy either: the folate guideline is a position, and the Cape Town figure is an association measured inside a cohort.

Sources

1. bnln-r2-10 · cross-sectional study
   Legumes were consumed by 31.1% of respondents. Median (interquartile range) daily legume intake among consumers was 40.8g (20.4-74.0) ... Chickpeas were most commonly consumed (67.0%), followed by lentils (14.5%) and dry beans (12.2%).
   Eur J Nutr, 2026 · checked 2026-09-24
2. bnln-r2-11 · cross-sectional study
   We also compared legume consumption patterns between consumers below US dietary recommendations for mature legumes (<37.5 g/day, marginal) ... In NHANES, legume consumption remained low in US adults and declined from 2011 to 2014 (mature legumes: 12.8 to 8.3%; dry beans: 10.0 to 6.5%).
   Nutrients, 2020 · checked 2026-09-24
3. bnln-r2-06 · mechanistic statement in a review
   ANFs are produced as a defense mechanism against biotic and abiotic stressors from insects, microorganisms, and also environmental conditions. From a nutritional perspective, these are considered antinutrients as they lower the quality of plant proteins by interfering with the bioavailability and absorption of nutrients.
   Compr Rev Food Sci Food Saf, 2025 · checked 2026-09-24
4. bnln-r2-07 · cross-sectional study
   Mean +/- SD vitamin B6 intake was 2.83 +/- 0.98 mg day(-1) and mean +/- SD protein intake was 56.6 +/- 21.7 g day(-1). Of the participants 4% showed vitamin B6 intakes lower than daily recommended intakes for Germany, 16% showed EAST-AC > 1.85 ... Due to the health implications of a marginal pyridoxine status, vegans should be encouraged to include foods with a high bioavailability of pyridoxine, such as beans, lentils and bananas, in the daily diet.
   Public Health Nutr, 2006 · checked 2026-09-24
5. bnln-r2-04 · risk assessment
   Some human cases of acute gastrointestinal illness have been linked to consuming undercooked beans containing active lectins. ... Adequate food processing, such as soaking and boiling beans, effectively deactivates lectins, so that they pose no health concerns in humans.
   EFSA, Risks for human health related to the presence of plant lectins in food, plain language summary, 2026 · checked 2026-09-24
6. bnln-r2-08 · case report
   Serum specific IgE antibodies were positive to Lupine albus (1.43 kU/l), peanut (4.32 kU/l), soy (2.15 kU/l), lentil (3.12 kU/l) and garbanzo (0.7 kU/l). ... In our case, reactivity with other legumes was also demonstrated, but only peanut allergy was relevant because boiled legumes were tolerated.
   Pediatr Allergy Immunol, 2005 · checked 2026-09-24
7. bnln-r2-01 · meta-analysis
   Findings from 21 trials (n = 940 participants) were included in the meta-analysis. The pooled analysis showed an overall significant weight reduction of -0.34 kg (95% CI: -0.63, -0.04 kg; P = 0.03) in diets containing dietary pulses ... compared with diets without a dietary pulse intervention over a median duration of 6 wk.
   Am J Clin Nutr, 2016 · checked 2026-09-24
8. bnln-r2-02 · meta-analysis
   Thirty-eight trials (52 trial comparisons, n=2095) with a median of 6 weeks and dose of 130 g/d (0.5-0.67 cup/d) showed that whole dietary pulses decreased low-density lipoprotein-cholesterol (mean difference, -0.14 mmol/L [95% CI, -0.19 to -0.08])
   J Am Heart Assoc, 2026 · checked 2026-09-24
9. bnln-r2-03 · meta-analysis
   A linear inverse relationship was shown for beans up to 1 cup/d for low-density lipoprotein-cholesterol (coefficient, -0.25 mmol/L/0.5 cup [95% CI, -0.48 to -0.02])
   J Am Heart Assoc, 2026 · checked 2026-09-24
10. bnln-r2-12 · case-control study
    A decreasing, statistically significant association was found with increasing intakes of green vegetables (OR = 0.54, 95% CI = 0.40-0.71 for 4th quartile), tomatoes (OR = 0.64, 95% CI = 0.45-0.91), beans/lentils/nuts (OR = 0.69, 95% CI = 0.53-0.91), and cruciferous vegetables (OR = 0.69, 95% CI = 0.52-0.91 for 3rd quartile).
    Nutr Cancer, 1999 · checked 2026-09-24
11. bnln-r2-14 · practice guideline
    Women should be advised to maintain a healthy nutritional diet, as recommended in Canada's Food Guide to Healthy Eating (good or excellent sources of folic acid: broccoli, spinach, peas, Brussels sprouts, corn, beans, lentils, oranges). (III-A) ... Women who could become pregnant should be advised to take a multivitamin containing 0.4 mg to 1.0 mg of folic acid daily. (II-1A)
    J Obstet Gynaecol Can, 2003 · checked 2026-09-24
12. bnln-r2-13 · prospective cohort study
    In women with HIV, consumption of milk/yoghurt/maas to drink/on cereals (aOR 0.35, 95% CI 0.18-0.68), tomato (raw/cooked) (aOR 0.50, 95% CI 0.30-0.84), green beans (aOR 0.41, 95% CI 0.20-0.86), mixed vegetables (aOR 0.49, 95% CI 0.29-0.84) and legumes e.g. baked beans, lentils (aOR 0.50, 95% CI 0.28-0.86) for 4-7 days a week reduced the odds of overweight/obesity
    BMC Public Health, 2021 · checked 2026-09-24
13. bnln-r2-05 · systematic review
    The findings identified potential concerns associated with the presence of plant secondary metabolites, including antinutritional factors, phytoestrogens, and oligosaccharides, in all the sources included. Also, these protein sources have been shown to display allergenic properties, either through the intrinsic presence of allergens or through cross-reaction. Further, the effects of food processing on these proteins remain poorly understood and no conclusive data are available to quantitatively assess their safety after processing.
    Compr Rev Food Sci Food Saf, 2025 · checked 2026-09-24
14. bnln-r2-09 · systematic review
    The search strategy identified 2,444 articles and five studies were included in this analysis. ... Although inconsistent, some studies demonstrated that whole pulses (pinto beans and chickpeas), cooked navy bean powder, and pulse-derived fibre (lupin kernel fibre), did impose changes to the microbiota that inhabit the human large intestine.
    Benef Microbes, 2020 · checked 2026-09-24