Pinto means “painted” or “dappled” in Spanish, and the name fits. Dry pinto beans are mottled beige and brown, but the speckles fade in the pot and the cooked beans turn a light brown or tan. They are the same species as black, kidney and navy beans, Phaseolus vulgaris, which was domesticated twice, separately, in Mesoamerica and the Andes.
A cup of cooked pinto beans (171 g) holds 15.4 g of fiber, 55% of the Daily Value, and 294 µg of folate, 74% of it. Gram for gram, only 6 of the 130 foods on this site have more folate. Cooked without salt they carry about 1 mg of sodium per 100 g.
The pinto bean trials are few and small, from 16 to 80 adults. One odd finding is about iron. Pinto hulls contain kaempferol, which blocked iron uptake in a lab gut-cell model. Yet in 13 women, only about 2% of the iron from pinto or great northern bean meals was absorbed either way, and vitamin C from orange juice roughly tripled it.
Health benefits of pinto beans
The top findings from 17 studies, strongest evidence first
What the stars mean
- Strong. Several randomized trials, pooled in a meta-analysis, point the same way, or regulators (FDA or EFSA) have approved the claim.
- Moderate. Good randomized trials support it, but there are fewer of them, or their results vary.
- Limited. Small, short or single trials, or mixed results. Promising, but it needs confirmation.
Population and lab studies get no stars: they show a link or a mechanism, not proof.
How we rate evidence →- ★★Lower “bad” LDL cholesterolEating about 130 g a day of pulses (beans, chickpeas, lentils, peas) lowered LDL a little (0.17 mmol/L) across 26 trials. In one 8-week trial, half a cup of pinto beans a day lowered it by 14 mg/dL.
- ★Smaller blood sugar rise after a rice mealIn 17 adults with type 2 diabetes, rice with pinto beans gave a smaller blood sugar rise after the meal than rice alone.
- ★Only about 2% of the iron is absorbedWomen absorbed about 2% of the iron from pinto or great northern bean meals. Vitamin C from orange juice roughly tripled it.
- ★Fewer than half reported more gasFewer than half of the people who ate half a cup of pinto or baked beans a day reported more gas in the first week.
- Population studyLinked to fewer returning colorectal polypsPeople who raised their dry bean intake the most had 65% lower odds of an advanced colorectal adenoma (a polyp) coming back. This covers dry beans, not pinto alone.
All 17 studies, strongest evidence first
Eating about 130 g a day of pulses (beans, chickpeas, lentils and peas pooled) lowered LDL cholesterol by 0.17 mmol/L
Pooled-pulse meta-analysis of 26 randomized trials (1,037 people) lasting at least 3 weeks. Diets built around pulses were compared with diets of the same calories without them. It is not specific to pinto beans. Apolipoprotein B and non-HDL cholesterol did not change, and the authors ask for longer, higher-quality trials.
Half a cup (130 g) of cooked pinto beans a day for 12 weeks lowered total cholesterol by about 8% in control adults and 4% in adults with pre-metabolic syndrome
Randomized trial of 80 adults, 40 with pre-metabolic syndrome and 40 controls. They ate pinto beans or an equal-calorie chicken soup every day. LDL and HDL cholesterol both fell in both groups, while triglycerides and glucose did not change. Results on gut bacteria and colon cancer risk were mixed.
Half a cup of pinto beans a day for 8 weeks lowered LDL cholesterol by 14 mg/dL, while black-eyed peas and carrots did not
Randomized crossover trial in 16 mildly insulin-resistant adults. Each ate half a cup of pinto beans, black-eyed peas or carrots (the placebo) daily for 8 weeks, with 2-week breaks. Total cholesterol fell 19 mg/dL on pinto beans. Triglycerides, HDL, C-reactive protein, insulin, glucose and HbA1c did not differ between the diets.
Pinto beans eaten with rice lowered the blood sugar rise after a meal compared with rice alone in adults with type 2 diabetes
Randomized crossover trial in 17 adults with type 2 diabetes, 14 of them on metformin. Each test breakfast had 50 g of available carbohydrate: white rice alone, or rice with pinto, black or red kidney beans. Blood glucose was lower after all three bean meals at 90, 120 and 150 minutes, and the total rise was lower for pinto and black beans but not kidney beans.
Women absorbed only about 2% of the iron from pinto or great northern bean meals, and vitamin C from orange juice roughly tripled it
Two randomized absorption experiments with radioiron tracers. The bean experiment had 13 women, who ate pinto or great northern bean meals with or without ascorbic acid from orange juice. Bean variety made no difference to absorption. A lab gut-cell model had predicted a gap between the varieties that did not show up in women.
Fewer than half of the people who ate half a cup of pinto or baked beans a day reported more gas in the first week
Questionnaires from three feeding trials, with 17 adults on pinto beans, black-eyed peas or carrots, 29 on baked beans, and 40 on pinto beans against 40 on soup. Only 19% reported more gas with black-eyed peas, and 3 to 11% reported more even on control diets. The authors say worries about gas may be exaggerated, but people vary.
A meal of pinto beans, corn tortilla and guacamole gave protein that was 77% digestible
Six healthy adults (3 men, 3 women) ate a paste of cooked pinto beans on toasted corn tortillas with guacamole. Isotope tracers measured how well the essential amino acids were digested. The digestible amino acid score was 83%, limited by methionine and cysteine. This was a very small study of one dish.
US adults whose diets included pinto, black or kidney beans or chickpeas scored higher on diet quality than adults who ate no beans
Analysis of US national survey data from 2001 to 2018. Four bean eating patterns scored 55.2 to 61.2 on the Healthy Eating Index, against 48.8 for the no-bean pattern, and the two heaviest patterns (about 1.7 to 2 servings a day) went with lower body weight. It cannot show cause. Some authors report consulting for food companies and associations.
Latino adults who ate half a cup or more of pulses a day had a lower prevalence of metabolic syndrome
Cross-sectional analysis of 6,958 adults aged 50 and older in the Hispanic Community Health Study/Study of Latinos, where 53.1% had metabolic syndrome. Pulses, mostly dry beans and lentils, were counted from two 24-hour diet recalls. Predicted prevalence was 0.52 at half to three-quarters of a cup a day and 0.49 above that. Pulses were pooled, and a snapshot cannot show cause.
People who raised their dry bean intake the most had 65% lower odds of an advanced colorectal adenoma coming back
Analysis of the Polyp Prevention Trial, a diet trial in people with a history of colorectal adenomas. Those in the top quarter for increase in dry beans, a median of 370% above their starting intake, had an odds ratio of 0.35 for advanced adenoma recurrence. There was no link with non-advanced adenomas. Dry beans were pooled, not pinto alone.
US adults who ate beans had a 22% lower risk of being obese
Analysis of US national survey data from 1999 to 2002 on 1,475 adults. Bean eaters also had lower body weight and waist size, a 23% lower risk of a large waist, and higher fiber, potassium, magnesium and iron intakes. Beans were pooled, and one 24-hour recall cannot show cause.
Pinto beans in the diet of hamsters cut non-HDL cholesterol by 31.9%, and the hulls alone by 53.6%
Forty-four hamsters ate a high-saturated-fat diet with 5% whole pinto beans or 0.5% pinto hulls for 4 weeks. Whole beans also lowered liver cholesterol by 45.1%, raised fecal cholesterol, and turned down genes for cholesterol production and absorption. These were animals, not people.
Cooked pinto beans in the diet of mice raised fecal butyrate and improved fasting blood glucose and glucose tolerance
Male mice ate a control or a high-fat, high-sugar diet, with or without 10% cooked pinto beans, for 30 days. Beans raised gut bacteria that make short-chain fatty acids and lowered inflammation markers in belly fat. This was an animal study.
A 5% pinto bean diet reduced tumor burden in mice with chemically induced colorectal cancer
Mice given a carcinogen and an irritant to trigger bowel tumors ate a 5% pinto bean diet or a control diet. The beans also reduced gut inflammation and enriched gut bacteria such as Akkermansia muciniphila. The result comes from mice only.
Pinto beans preserved blood vessel relaxation in mice fed an atherogenic diet, but only in mice with a working IL-10 gene
Female mice ate a high-fat, high-cholesterol diet with or without 5% pinto beans. In normal mice, beans kept gut bacteria diverse and fecal butyrate steady. Mice lacking IL-10 had impaired vessels whatever they ate, and beans did not help them.
Kaempferol in pinto bean hulls blocked iron uptake in a lab gut-cell model
Lab digestion and human Caco-2 cell tests of white, red, pinto and black beans. White beans released more usable iron than the colored beans. Kaempferol cut iron uptake by 15.5% at 40 µM and by 62.8% at 1000 µM. The human absorption trial above found no difference between pinto and great northern beans.
Rats absorbed copper from cooked pinto beans at least as well as from copper sulfate
Rats made copper-deficient for 4 weeks were refilled for 2 weeks with copper from pinto beans at 10% or 20% of the diet, or from copper sulfate. Across 10 measures of copper status, bean copper worked at least 100% as well. For liver and heart copper it was 138 and 140%. This was an animal study.
Who should be careful with pinto beans
Most people can eat pinto beans freely once they are cooked. Take a little care if one of these applies:
- Raw or undercooked dried beans. Phytohaemagglutinin, a lectin, occurs in many beans and is highest in red kidney beans; as few as four or five raw kidney beans can cause vomiting within 1 to 3 hours. The FDA gives no figure for pinto beans, though a lab comparison classed pinto lectin as a toxic type. Soak dried beans, drain them and boil in fresh water until fully tender; canned beans are already cooked.
- Irritable bowel syndrome or a gassy gut. Monash University says legumes are naturally high in galacto-oligosaccharides, and that canned beans, or beans boiled and drained, tend to be lower in FODMAPs. It gives no serving size for pinto beans in that post.
- Kidney stones. A lab analysis found 193 mg of total oxalate in a serving of refried beans, an amount that exceeds the oxalate advice for people with a history of calcium oxalate stones. If you have had stones, ask your clinician how much suits you.
How to choose, store and eat pinto beans
- Dried: simmer for 90 to 120 minutes until tender but firm. A hot soak (boil 2 to 3 minutes, then soak up to 4 hours) or an unsoaked pressure cooker (15 to 20 minutes) shortens it, and 1 lb (2 cups) dry makes about 6 cups cooked.
- Canned: already cooked, and a 15-ounce can gives about 1¾ cups drained. Draining and rinsing washes out some of the FODMAPs, per Monash. Trials used half a cup a day, and home-cooked beans without salt have about 1 mg of sodium per 100 g.
- Refried: cooked beans mashed and fried in fat, so the sodium and fat depend on the recipe or the can, and the label is the guide. Cool a big batch in shallow pans: in large stockpots, Clostridium perfringens grew by about 1.2 log in refried pinto and black beans.
Sort dried beans to remove stones and damaged seeds. Refrigerate cooked beans in shallow containers and use them within 3 to 4 days, or freeze the extra within 4 days of cooking. In USDA Pesticide Data Program tests of 372 canned pinto bean samples in 2009, residues turned up in 12 of 54,296 tests, and one sample was flagged for a residue with no set limit.
Sources
- Phytohaemagglutinin (kidney bean lectin). Bad Bug Book, second edition. US Food and Drug Administration. 2012.
- Weder JK, Telek L, Vozári-Hampe M, Saini HS. Antinutritional factors in anasazi and other pinto beans (Phaseolus vulgaris L.). Plant Foods Hum Nutr. 1997.
- Including legumes on a low FODMAP diet. Monash FODMAP blog. 2016.
- Massey LK, Palmer RG, Horner HT. Oxalate content of soybean seeds (Glycine max: Leguminosae), soyfoods, and other edible legumes. J Agric Food Chem. 2001.
- Cooking dry beans from scratch can be quick. University of Nebraska–Lincoln Extension.
- Cevallos-Cevallos JM, Akins ED, Friedrich LM, Danyluk MD, Simonne AH. Growth of Clostridium perfringens during cooling of refried beans. J Food Prot. 2012.
- Pesticide Data Program annual summary, calendar year 2009. USDA Agricultural Marketing Service.
- Beans, pinto, mature seeds, cooked, boiled, without salt (FDC ID 175200). USDA FoodData Central.
History of pinto beans
In Spanish, pinto means painted, dappled or spotted, and the bean is named for its speckled coat. It is the most popular bean by crop production in northern Mexico and the southwestern United States.
The common bean was domesticated twice, independently: once in Mesoamerica and once in the Andes. A genetic study of 214 wild and domesticated plants pointed to the Oaxaca valley as the likely origin of the Mesoamerican one, and to southern Bolivia and northern Argentina for the Andean one, though the authors urge caution.
In New Mexico, Pueblo peoples grew pinto beans with corn and squash since prehistoric times. In 1965 the state legislature named chile and frijoles, the pinto bean, its official state vegetables, after lawmakers argued the two were inseparable.
Today the crop is grown on the northern plains. North Dakota produced about 71% of the US pinto crop in 2024, and Nebraska calls itself the second-largest producer.
Stored pinto beans darken after harvest, which cuts the value of the crop because buyers prefer lighter beans. Breeders have found a gene variant, called Psd, behind a slow-darkening type of pinto.
Sources
- Pinto bean. Wikipedia.
- Bitocchi E, Bellucci E, Giardini A, et al. Molecular analysis of the parallel domestication of the common bean (Phaseolus vulgaris) in Mesoamerica and the Andes. New Phytol. 2013.
- State vegetables. New Mexico Secretary of State.
- North Dakota agriculture rank in the nation, 2024 data. USDA National Agricultural Statistics Service.
- Dry beans 101. Nebraska Dry Bean Commission.
- Islam NS, Bett KE, Pauls KP, Marsolais F, Dhaubhadel S. Postharvest seed coat darkening in pinto bean (Phaseolus vulgaris) is regulated by Psd, an allele of the basic helix-loop-helix transcription factor P. Plants People Planet. 2020.
Frequently asked questions about pinto beans
Are pinto beans good for you?
For most people, yes. A cup of cooked pinto beans (171 g) has 245 calories, 15.4 g of protein, 15.4 g of fiber (55% of the Daily Value) and 294 µg of folate (74%). In a trial of 16 adults, half a cup a day for 8 weeks lowered LDL cholesterol by 14 mg/dL. The pinto trials are small, and no pinto finding here reaches strong evidence.
Are pinto beans high in protein?
They are a good plant source. Cooked pinto beans have 9.01 g of protein per 100 g, or 15.4 g in a cup (171 g), and about 28% of their calories come from protein. The protein is slightly short in methionine and cysteine, which gives an amino acid score of 89 out of 100. In 6 adults, a pinto bean, tortilla and guacamole meal gave protein that was 77% digestible.
Are pinto beans healthier than black beans?
They are close. Per cup of cooked beans, pinto has 245 calories, 15.4 g of protein, 15.4 g of fiber and 294 µg of folate, and black beans have 227 calories, 15.2 g of protein, 15 g of fiber and 256 µg of folate. Pinto has more potassium (746 against 611 mg) and black beans more magnesium (120 against 85.5 mg). In 17 adults with type 2 diabetes, both bean and rice meals lowered the blood sugar rise compared with rice alone.
Do pinto beans lower cholesterol?
Possibly, a little. In 16 adults, half a cup a day for 8 weeks lowered LDL by 14 mg/dL. In 80 adults, 12 weeks of half a cup lowered total cholesterol by about 8% in controls and 4% in adults with pre-metabolic syndrome, though HDL fell too. Across 26 trials of pulses as a group, LDL fell by 0.17 mmol/L.
Do you have to soak pinto beans?
No, but soaking shortens the cooking. A hot soak means boiling for 2 to 3 minutes and then soaking up to 4 hours, and unsoaked beans take 15 to 20 minutes in a pressure cooker. On the stove, simmer 90 to 120 minutes until tender but firm. Drain and rinse after soaking, and never eat dried beans undercooked.
Do pinto beans cause gas?
They can, but fewer people notice than expected. In three feeding trials, fewer than half of those eating half a cup of pinto or baked beans a day reported more gas in the first week, and 3 to 11% reported more even on control diets. Monash University says canned beans, or beans boiled and drained, tend to be lower in FODMAPs.
Are pinto beans good for people with diabetes?
They can fit, but the evidence is small. In 17 adults with type 2 diabetes, pinto beans with rice lowered the blood sugar rise after a meal compared with rice alone, at 90, 120 and 150 minutes. A cup of cooked pinto beans has 15.4 g of fiber and 29.4 g of net carbs. Check portions and choices with your care team.
Are pinto beans good for weight loss?
No pinto bean trial tested weight loss. Cooked pinto beans have 143 calories and 9 g of fiber per 100 g, so they fill a plate for few calories. In US survey data, adults who ate beans had a 22% lower risk of being obese, but that is a link, not proof, and beans were pooled.