The One Protein Gastroenterologists Want You to Eat More Often

Beans are found in some of our favorite foods — just think chili, tacos and dips. However, this great source of protein can sometimes be overshadowed by other foods (like meat) despite the wide variety of benefits beans provide.

Gastroenterologists tend to recommend beans for most people due to the benefits they offer for your digestive system and entire body. Here's why doctors want you to eat more beans as a source of protein (and the cases in which you should hold back).

"For people who are vegan or choose to limit their meat intake, beans are a great protein alternative to meat," says Niket Sonpal, MD, a New York-based gastroenterologist, internist and adjunct professor at Touro College.

"Protein is composed of chains of amino acids that are linked together. Beans contain large amounts of amino acids, making them excellent sources of protein."

However, beans don't include the less desirable aspects you might find in, say, cuts of meat — like blood cholesterol-raising saturated fat.

"Beans are considered a good source of protein because they can provide anywhere from 30 to 60 percent of the recommended daily amount of protein intake," says Jeff Scott, MD, a board-certified gastroenterologist. "They are a sort of a superfood because they contain proteins and minerals and lack saturated fat."

Here's how much protein you'll get in just 1 cooked cup of various beans:

• Black beans 15.2 g
• Fava beans 12.8 g
• Pinto beans: 15.6 g
• Navy beans: 14.8 g
• Kidney beans: 15.2 g
• Lima beans: 11.6 g

Beans also contain some omega-3 fatty acids, plus folate, iron, magnesium and zinc, says Lawrence Hoberman, MD, a board-certified gastroenterologist.

"The fatty acids in beans nourish the intestinal microbiome," Dr. Hoberman says. "They provide nourishment for the intestinal lining cells, strengthening their ability to prevent harmful toxins and bacteria from entering our bloodstream. They also enhance our intestinal immunity."

One of the greatest perks of beans is that they're a protein source that comes with healthy fiber. "Beans can be an enormous benefit to gastrointestinal health," says Michael Papper, MD, a board-certified gastroenterologist at Florida Digestive Health Specialists.

"They are an excellent source of fiber, regulating bowel movements, blood sugar and cholesterol. This reduces the risk of fatty liver disease and the adverse effects of increased blood sugar on the GI tract, such as gastroparesis — a disorder that slows or stops the movement of food from the stomach to the small intestine — and constipation."

As part of a fiber-rich diet, beans may also play a role in reducing the risk of diverticulosis (when bulging pouches develop in the digestive tract) and improve symptoms in people with irritable bowel syndrome (IBS), Dr. Papper adds.

Beyond your GI health, eating beans can help you get more fiber. Soluble fiber, like that found in beans, may help decrease total blood cholesterol levels by lowering LDL "bad" cholesterol, according to the Mayo Clinic. High-fiber foods are also linked to reduced blood pressure and inflammation.

Dietary fiber intake has been linked to a lower risk of heart disease, which is the top cause of death in the United States. Each 10-gram increase in daily fiber was associated with a 15 percent lower risk of death from ischemic heart disease in a May 2012 study of more than 306,000 people published in the ​European Journal of Clinical Nutrition​​.​

"Navy beans have the most fiber, with nearly 20 grams of soluble fiber in one cup," Dr. Sonpal says. "Black beans and kidney beans are also good choices when looking for added fiber."

Incorporating beans into your diet can also help you maintain or reach a healthy weight. High-fiber foods are often less calorie-dense than other foods — so you end up eating fewer calories for the same volume of food, per the Mayo Clinic.

"Beans are calorically lower than most other protein sources like red meat and chicken," Dr. Sonpal says. "They are a great addition to a diet for anyone looking to lose weight while also nourishing their body. The high amounts of fiber in beans can help keep people full for longer periods of time, without the desire to snack."

Upping fiber intake by only about 4 grams per day is associated with an extra 3.25 pounds of weight loss over six months in people on various diets, per an October 2019 study in ​The Journal of Nutrition​​.​ By helping to keep your digestive system healthy, beans may also support your healthy gut bacteria — which could play a role in your weight.

"Beans may regulate the intestinal barrier and help increase the number of 'good' intestinal bacteria, which helps ward off conditions like inflammation, obesity, diabetes and heart disease," Dr. Papper says.

"Beans are rich in folic acid and antioxidants that are linked to lower risks of certain cancers including colorectal cancer, the third most common cancer in men and women combined," Dr. Papper says.

Antioxidants are important because they can prevent or delay some types of cell damage. It's best to get them from a healthy diet high in plant-based foods, which are excellent sources of antioxidants. FYI, research has not shown that antioxidant supplements are helpful in preventing disease, per the National Institutes of Health (NIH).

When you work out, digest food, smoke or are exposed to sunlight or air pollution, your body forms unstable molecules called free radicals — which can cause oxidative stress, a process that leads to cell damage, per the NIH.

Oxidative stress is believed to play a role in a several diseases, including cancer, diabetes, heart disease, Alzheimer's disease, Parkinson's disease and age-related macular degeneration and cataracts. Lab experiments have shown that antioxidant molecules can counteract oxidative stress, per the NIH.

For some people, beans may cause stomach upset or other issues. Pay close attention to how your body reacts after eating beans, so you can flag any concerns for your doctor.

"Beans aren't a good choice for everyone," Dr. Papper says. "For those prone to slow stomach emptying, such as people with gastroparesis, the high fiber content of beans can slow stomach emptying, leading to discomfort and nausea."

Compounds in beans may also exacerbate certain conditions: "Fava beans contain tyramine and likely should be avoided by those with constant headaches or high blood pressure," Dr. Sonpal says. "Tyramine is a vasoactive amine [a substance that affects blood vessels] that can raise blood pressure and trigger migraines in those susceptible."

Beans contain complex sugars called oligosaccharides, and our bodies don't have the enzymes to digest them. "You can help break down the sugars by soaking the beans before cooking them, and using long, slow cook times," Dr. Scott says.

"The sugars that do make it to your colon undigested are fermented by your gut bacteria." This is what leads to the famous gassiness associated with beans. Dr. Scott's recommendation is to include beans in the diet every two or three days — but don't overdo it.

Certain supplements, like Beano, can also help control the uncomfortable side effects of gas.

"These supplements have an enzyme called alpha-galactosidase, which breaks down the oligosaccharides before they get to the intestinal bacteria, so gas production never occurs," Dr. Papper says.

The bacteria in your stomach also produces gas as a byproduct when it digests a lot of fiber, which can cause flatulence. The beans you choose and how you actually eat them can make a difference.

"Some beans are known to cause less gas than others — lentils and black-eyed peas have less fiber and carbohydrates than chickpeas and navy beans," Dr. Sonpal says. "Since some beans can be more difficult to digest, chewing slowly can help the stomach break down the rest of the food more effectively."