This Facts About reviews beans and lentils and gives examples of foods to choose from as well as foods to avoid. We provide a guide for selecting an appropriate portion size, and recommendations for incorporating healthy changes into your diet.

What are the recommended servings per day?

• 1-3 servings per day

Why choose legumes?

• Low in fat
• Excellent source of protein
• Good source of fiber
• Contain iron, zinc, calcium, selenium, and folate
• Rich in antioxidants
• Provide a low glycemic index (GI) / glycemic load (GL)
• May help reduce the risk of chronic diseases, such as, heart disease, diabetes mellitus,obesity and cancer

What are legumes?

Beans, peas, lentils, and peanuts are collectively known as legumes, which are plants that have pods with tidy rows of seeds inside. Various foods in this category metabolize differently and provide different nutrients. For example, peanuts, which are usually consumed in ways similar to tree nuts are actually in thelegume family and grow underground. They contain more fat and fewer carbohydrates than other legumes. Sugar snap peas contain fewer calories, carbohydrates, and protein per serving than other legumes and are used in cooking as a vegetable. Soy beans are unique for their high isoflavone and essential amino content. They are also used to make such a wide variety of foods unlike other beans in this category. For these reasons, we have listed peanuts in Healthy Fats, fresh green peas in Vegetables, and soy beans in Soy. Please read these individual Facts About sheets for more information.

Legumes have many of the nutrients recognized as important in preventing heart disease, cancer, obesity, and other chronic diseases. They are a vegetarian source of protein for the diet. For non vegetarians, they offer an alternative source of protein with less fat and more fiber.

Selected Food Sources with Serving Sizes, Protein, and Fiber Content

Specific Considerations

Protein Complementation

Protein is made up of building blocks called amino acids and must be consumed in the diet for building new proteins in the body.  Our bodies can make some amino acids from the protein we eat, but not others; the ones the body cannot make are considered essential amino acids because they must be consumed from the diet.

• Dairy and meat usually contain all of the essential amino acids and are considered to provide complete proteins.  However, they often contain saturated fat and cholesterol.
• Grains, fruits and vegetables lack at least one of the essential amino acids and are considered to provide incomplete proteins.  These items, when eaten in combination can fulfill requirements for essential amino acids in the diet.
• For the most benefit from complimentary protein foods, plant sources of protein such as legumes, seeds and whole grains should be eaten in combination and during the same day, but do not necessarily need to be eaten during the same meal as once thought.
• There are many examples of common plant-based dishes that contain adequate essential amino acids:  brown rice and beans, peanut butter and whole wheat bread, cornbread and pinto beans and refried beans with wheat or corn tortillas.
• Dairy products can also be added to a meatless dish to enhance the protein content of a meal.

Canned versus Dried Beans

• Canned beans are fast and easy to use
• Many canned beans are high in sodium. To avoid this, buy “no added salt” products or rinse thoroughly.
• Dried beans have a fresher taste than canned beans and soaking times vary. Read product label for instruction.

Intestinal Gas

Many people who eat beans have a problem with intestinal gas. Humans are missing an enzyme required to break down raffinose sugars found in beans. The bacteria in our gut feast on these sugars, giving off hydrogen and carbon dioxide and causing intestinal gas. Some people avoid beans due to the intestinal gas or bloating they may produce. Gradually increasing the amount of beans you eat over several weeks can help in overcoming this.

Ideas to increase beans, peas & lentils

1. Choose beans as your protein choice instead of high fat meat or dairy products.
2. Keep pantry stocked with a variety of canned legumes for a quick meal or side dish.
3. If you're new to beans, start with a small amount and increase gradually.
4. Consider vegetarian days.
5. Change your favorite recipe by replacing half the meat with legumes.
6. Try a new legume each week.
7. Enjoy bean soups and a salad for lunch and / or dinner.

To decrease intestinal gas from beans, peas, & lentils

1. Mix 1/8 teaspoon of baking soda into the soaking water. It helps leach out raffinose sugars, reducing intestinal gas.
2. Drain and rinse canned beans. That will get rid of some of the gas-causing raffinose sugars (and almost half of the unwanted sodium).
3. Never cook beans in the water they've soaked in. It's loaded with the gas-causing raffinose sugars.

This Facts About document is published by Monica Myklebust, MD, and Jenna Wunder, MPH, RD, at University of Michigan Integrative Medicine Clinical Services. Our mission is to care for people using an Integrative Medicine model that reaffirms the importance of relationship between practitioner and patient, focuses on the whole person, is informed by evidence, and makes use of all appropriate therapeutic approaches to achieve optimal health and healing.

Resources

Beans and Legumes
University of Iowa Hospitals and Clinics
Available at: www.uihealthcare.com
Accessed April 14, 2006

Fiber: Start Roughing It!
Harvard School of Public Health
www.hsph.harvard.edu
Accessed April 14, 2006

Legumes
Linus Pauling Institute’s Micronutrient Information Center
http://lpi.oregonstate.edu
Accessed April 14, 2006

Legumes:  Using beans, peas and lentils instead of meat
Mayo Clinic
www.mayoclinic.com
Accessed April 14, 2006

Protein:  Moving Closer to Center Stage
Harvard School of Public Health
www.hsph.harvard.edu
Accessed April 21, 2006

Protein in Diet
Medline Plus – A Service of the US National Library and the National Institute of Health
www.nlm.nih.gov/medlineplus
Accessed April 21, 2006

USDA Nutrient Data Laboratory
Available at: www.ars.usda.gov/nutrientdata
Accessed on April 14, 2006

 
Original Research and Review Articles

Bazzano, LA, et al.  Legume consumption and risk of coronary heart disease in US men and women.  Archives of Internal Medicine.  2001;161:2573-2578.

Kushi LH, et al  Cereals, legumes, and chronic disease risk reduction: evidence from epidemiologic studies. American Journal of Clinical Nutrition. 1999;70(suppl):451S-458S.

Messina MJ.  Legumes and soybeans: overview of their nutritional profiles and health effects. American Journal of Clinical Nutrition. 1999;70(suppl):439S-450S.

Marlett JA, et al.  Position of the American Dietetic Association:  health implications of dietary fiber.  Journal of the American Dietetic Association 2002;102(7):993-1000.