Pinto beans are a variety of the common bean (Phaseolus vulgaris) that are especially popular in Mexican and Latin American cuisine. They are known for their brown speckled skin and their creamy texture when cooked. However, some people experience digestive discomfort like gas, bloating or stomach pain after eating pinto beans. There are a few reasons why pinto beans may irritate your stomach:
Quick answer: Pinto beans contain complex sugars called oligosaccharides that our bodies cannot fully digest. This leads to gas and abdominal discomfort. Soaking, sprouting and thorough cooking can help reduce oligosaccharides and make pinto beans easier to digest. People with Irritable Bowel Syndrome (IBS) may be more prone to reaction.
Why are beans hard to digest?
Like many legumes, pinto beans contain complex sugars called oligosaccharides, including raffinose and stachyose. The human digestive system lacks the necessary enzymes to fully break down these oligosaccharides. Instead, they travel to the large intestine mostly intact where they become food for our gut bacteria.
As the gut bacteria ferment the oligosaccharides, they release hydrogen, carbon dioxide and methane gasses which can lead to bloating, flatulence and discomfort. Different types of legumes contain varying amounts of raffinose and stachyose, which is why some cause more digestive trouble than others.
Kidney beans and black beans are particularly gassy culprits, while lentils and split peas are easier on the system since they contain less oligosaccharides. Pinto beans fall somewhere in the middle in terms of gas-inducing qualities.
Other indigestible compounds
In addition to oligosaccharides, beans contain other compounds our bodies struggle to break down:
- Resistant starch – starch that resists digestion in the small intestine
- Fiber – plant material like cellulose, pectins and gums
- Lectins – proteins that bind to carbohydrates
- Phytic acid – found in the outer husk of beans, binds to minerals
Like oligosaccharides, these compounds travel to the large intestine undigested where bacteria ferment them, which can lead to unwanted gas and bloating.
Why do pinto beans affect me but not others?
Not everyone experiences adverse reactions to pinto beans. Tolerance levels vary by individual based on:
We each host trillions of bacteria in our gastrointestinal tract that are essential for digestion and overall health. The specific makeup of this gut flora is different for everyone based on genetics, age, diet and other factors.
Someone with a diverse community of healthy gut microbes may be better equipped to break down and digest oligosaccharides without discomfort. On the other hand, an imbalance of gut bacteria could impair digestion and increase gas.
If beans are not soaked, sprouted or cooked properly, more of the indigestible compounds remain intact to reach the colon and cause problems. Thorough cooking helps break down some of the oligosaccharides and other carbohydrates.
People with digestive disorders like irritable bowel syndrome (IBS) or small intestinal bacterial overgrowth (SIBO) may experience more gas, bloating and abdominal pain when eating beans and other high FODMAP foods.
Those with carbohydrate malabsorption issues or non-celiac gluten sensitivity can also have trouble properly digesting beans.
Some individuals may simply have a higher sensitivity to compounds found in beans like lectins. This can cause inflammation in the gastrointestinal tract, leading to discomfort.
Those with hereditary alpha-gal syndrome are unable to properly metabolize galactans found in legumes, which triggers an immune reaction.
Tips for easing pinto bean digestion
If pinto beans give you tummy trouble, there are steps you can take to make them more digestible:
Soak beans before cooking
Soaking dried pinto beans for at least 8 hours before cooking can help reduce raffinose oligosaccharides by around 30%. The soaking water contains some of the sugars and compounds that cause gas. Discard this water before cooking.
Sprouting beans for 1-2 days prior to cooking can lower oligosaccharides even further, by around 50-60%, making digestion easier.
Cook beans thoroughly
Cook pinto beans until very soft – the longer they cook, the more digestible they become. Undercooked beans are more likely to cause stomach upset.
Try canned beans
Canned pinto beans are typically soaked and cooked before canning, which reduces oligosaccharides and lectins. Rinse canned beans before eating to remove extra sodium.
Add acidic ingredients
Adding a splash of vinegar, lemon juice or other acids when cooking can help break down indigestible sugars and compounds.
Spice it up
Herbs, spices and seasonings containing carminatives like cumin, ginger, turmeric, fennel, rosemary and sage may relieve gas and bloating.
Take enzyme supplements
Over-the-counter products like Beano contain alpha-galactosidase, an enzyme that helps break down oligosaccharides before they reach the colon.
Increase soluble fiber
Soluble fiber from oats, nuts, flax and veggies can help slow digestion, allowing the body more time to absorb nutrients and gas-causing compounds.
Check for food intolerances
Consider eliminating common triggers like dairy, eggs, nuts, gluten or other high FODMAP foods to see if it improves your bean tolerance.
See a doctor or dietitian
If beans consistently cause severe abdominal pain or diarrhea, seek advice to rule out underlying conditions like IBS, SIBO, celiac disease or a bean allergy.
Health benefits of pinto beans
Despite the potential for gas and bloating, there are lots of good reasons to include pinto beans as part of a healthy diet:
One cup of cooked pinto beans provides over 15 grams of plant-based protein. The protein in beans is considered high quality and contains essential amino acids.
Pinto beans are packed with both soluble and insoluble fiber, providing nearly 15 grams per cooked cup. Fiber supports healthy digestion, stabilizes blood sugar, lowers cholesterol and promotes feelings of fullness.
Pinto beans are a great plant-based source of iron, delivering around 20% of the recommended daily amount per serving. Iron is necessary for transporting oxygen around the body.
Also known as vitamin B9, folate is an important nutrient for cell growth and division. Just one cup of cooked pinto beans contains over half your daily folate needs.
Magnesium, potassium and other minerals
Pinto beans supply a range of minerals like magnesium, potassium, manganese and copper that play diverse roles in maintaining good health.
No cholesterol or saturated fat
Unlike animal proteins, beans contain zero cholesterol or saturated fat, making them heart healthy and beneficial for cholesterol levels.
With only about 245 calories per cooked cup, beans like pintos are nutrient-dense but low in calories – helpful for managing weight.
Blood sugar regulation
Despite their carbohydrate content, beans have a low glycemic index. This, along with their fiber and protein, helps slow the absorption of sugar into the bloodstream and prevent spikes and crashes.
Some research has found an association between higher bean consumption and reduced risk for cancers like breast, prostate and colorectal.
Population studies have linked regular intake of beans and legumes to lower risk of death from all causes. Their versatility also promotes nutrient-dense eating.
Beans require fewer resources like water, fuel and land compared to most other protein sources. Their nitrogen-fixing properties can help improve soil health as well.
The bottom line
Pinto beans are packed with protein, fiber, vitamins and minerals. Their high nutritional value makes them a healthy addition to the diet for most people. However, their oligosaccharide content can cause unpleasant gas and bloating in some individuals.
Soaking, sprouting, cooking and seasoning pinto beans properly can all help increase digestibility. If bean discomfort persists, limiting portions or trying other legumes like lentils or split peas can help provide the benefits without the unwanted side effects.
Those with underlying conditions like IBS should be especially mindful of beans’ impact on their gut. But with some care around preparation and portion sizes, most people can enjoy pinto beans and profit from their significant health perks. They are economical, environmentally friendly and fit well into a versatile range of recipes.
Frequently Asked Questions
Why are pinto beans gassy?
Pinto beans contain complex sugars called oligosaccharides that the human body struggles to fully digest. These indigestible sugars travel to the large intestine where they ferment, releasing gasses that can lead to bloating, flatulence and stomach discomfort.
How can I reduce gas from pinto beans?
Soaking, sprouting and thoroughly cooking beans helps break down some of the oligosaccharides. Discard the soaking water, rinse canned beans, and add acidic ingredients, carminatives or Beano when cooking. Check for food intolerances and see a doctor if needed.
Do all beans cause gas?
All beans contain some oligosaccharides and anti-nutrients that can cause gas, but some beans are worse than others. Lentils, split peas and black-eyed peas tend to be easier to digest than kidney beans, chickpeas or navy beans.
Can I be allergic to pinto beans?
Yes, it’s possible to be allergic to pinto beans and other legumes. An allergy can cause intestinal distress along with symptoms like hives, swelling, vomiting or anaphylaxis in severe cases. See an allergist if a bean allergy is suspected.
Are canned pinto beans less gassy?
Canned pinto beans tend to be less gas-producing since they are soaked and cooked before canning. Rinsing canned beans helps remove excess sodium and indigestible sugars that contribute to gas. But some individuals may still react.