Pulses: Are Pulses a Misunderstood Food Group?
By Karen Collins, MS, RDN, CDN, FAND
Today’s Dietitian
Vol. 25 No. 8 P. 20
Help clients bypass misconceptions and include more of these nutritional gems.
Some people use the term “pulses” interchangeably with “legumes.” However, legumes encompass a broad category of plants with seeds that grow in pods. The differences among legumes lead to distinct nutritional profiles. The most common types fall into three categories1,2:
• Pulses are the dry edible seeds from within a pod. Although there are multiple types and hundreds of specific examples, pulses in the United States often are grouped into four main types: dry beans, dry peas, chickpeas, and lentils.
• Undried (fresh or green) legumes are harvested while still green (before drying). They can be consumed with their pods (eg, green beans and sugar snap peas) or without their pods (eg, green peas). In the 2020–2025 Dietary Guidelines for Americans (DGA), green peas are grouped with starchy vegetables, while the rest are with “other vegetables” such as celery, cabbage, onions, and peppers.3
• Oilseed legumes are nutritionally unique because they’re higher in fat (primarily unsaturated) and lower in fiber than other legumes. Peanuts and soybeans are the two major examples.
Inconsistent Guidelines
In the Healthy US-style or Mediterranean dietary pattern, adults are advised to consume 11/2 cups of pulses per week in a 2,000-kcal/day diet, according to the 2020–2025 DGA (where they’re listed under the Beans, Peas, Lentils subgroup of vegetables).3 The DGA vegetarian dietary pattern calls for an additional 6 cups per week in a 2,000-kcal/day diet as part of protein-supplying foods, for a total of about 71/2 cups of pulses per week.
However, major dietary recommendations from the American Heart Association, the American Diabetes Association, and the American Institute for Cancer Research, which focused on reducing specific health risks, all include pulses as part of a dietary pattern to promote cardiovascular health, manage diabetes and prediabetes, and reduce risk of cancer.4-7 Yet, none include specified amounts.
Nutritional Benefits
Pulses are advantageous to a health-promoting diet due to the nutrients and compounds they provide and can serve as replacements for foods that should be limited in a healthful dietary pattern. Pulses boost nutrient-density and offer typically underconsumed nutrients. Calcium, potassium, dietary fiber, and vitamin D are underconsumed and are a public health concern for the general US population, according to the DGA.3 Iron is also a part of that list for female adolescents and women of childbearing age. Pulses are flagged as nutrient-dense sources of three of these five nutrients, including potassium, dietary fiber, and iron. In addition, the DGA notes that protein is underconsumed by many adolescent females and adults aged 71 and older and highlights beans, peas, and lentils as a food category that’s underconsumed in these populations and could help fill that gap. Many pulses also are good sources of folate and magnesium, which also are classified by the DGA as underconsumed nutrients.
People who consume pulses have higher calorie-adjusted intakes of dietary fiber, folate, and magnesium than those who consume none, according to an analysis of National Health and Nutrition Examination Survey data.8 And those who consume higher amounts—just under 0.5 cup equivalents per day—also have higher energy-adjusted intakes of potassium, zinc, iron, and choline compared with nonconsumers. The National Health and Nutrition Examination Survey is an observational, cross-sectional study, so it’s possible that people who consume more pulses also make other dietary choices that increase consumption of these nutrients.
Pulse Consumption Promotes Health
• Cardiometabolic health: Prospective observational studies show that regular pulse or total legume consumption is associated with lower risk of CVD.9 In randomized intervention trials lasting at least four weeks that analyzed effects on markers of cardiometabolic health, legumes, which included pulses and soyfoods, were the second strongest out of 10 food groups for reducing LDL cholesterol.10 And in combined analysis of all 10 biomarkers of cardiometabolic health (including those related to lipids, glycemic control, blood pressure, and inflammation), the effects of legumes again were rated second.
• Cancer risk: Pulses go a long way to help fill the gap in dietary fiber in Western diets to help fulfill the recommendation for at least 30 g fiber per day to reduce cancer risk.6 However, although pulses often are recommended as part of a diet to reduce cancer risk, research hasn’t yet shown a consistent association of pulse consumption with lower risk of cancer—whether overall or specific types.6,11
• Role in a healthful dietary pattern: Healthy Eating Index scores for a healthful dietary pattern reflect pulse consumption that aligns with current recommendations and are associated with key metrics of better health.12,13 The question is whether more frequent consumption, such as a half-cup daily, will create a dietary pattern that better supports health. Those who favor recommending increased amounts of pulses note that the overall impact of pulses’ nutrient quality, and value as a replacement for other foods, is diluted when it’s averaged over several days.1
Overcoming Barriers
Dietitians can facilitate greater consumption of pulses by asking clients what barriers they face and then providing relevant education and coaching that address those barriers.
“In my practice, patients report that they didn’t grow up eating beans or that they don’t like the taste and have limited knowledge of how to prepare beans,” says Maya Feller, MS, RD, CDN, author of Eating From Our Roots: 80+ Healthy Home-Cooked Favorites From Cultures Around the World, based in Brooklyn, New York.
RDs also can provide clients with strategies to prepare pulses. “The soaking and cooking process for dry pulses is often a barrier for US consumers to prepare them at home,” says Madison Jacobson, director of marketing for the USA Dry Pea and Lentil Council and the American Pulse Association in Moscow, Idaho. “Many consumers are unaware that split peas and lentils do not require soaking before cooking. And both will cook in 45 minutes or less.” Canned and frozen pulses offer a solution if soaking and cooking time is too much of a barrier, and a pressure cooker can significantly reduce the time needed to prepare dry pulses.
In addition, media headlines based on research taken out of context may instill fears of lectin compounds in pulses. Claims linking lectins to chronic inflammation and gut damage are based on laboratory studies using isolated lectins or raw beans.14 However, lectins are neutralized in cooking, and since they’re water soluble, they’re largely removed by cooking or canning in water.
Some people may fear that pulses are “fattening” or that they will impede blood sugar management. Dietitians should explain that pulses are categorized as low in calorie density and that greater consumption of pulses and other legumes is associated with a decreased risk of weight gain, overweight, and obesity, and better glycemic control.10,15 In randomized, controlled human intervention trials, people achieved modest weight loss and lower body fat by eating a serving of pulses daily, even without intentionally reducing total calories.16
Finally, it’s time to address the elephant in the room: gas production. Gut bacteria produce gas as they form beneficial short-chain fatty acids from prebiotic compounds in pulses. However, dietitians can explain that when people gradually increase these foods and regularly include them, they often build up a tolerance. Commercial digestive aids with alpha-galactosidase can alleviate digestive discomfort, if needed.
Pulses Are Flexible
In addition to addressing barriers with clients, dietitians can provide examples of how they can prepare pulses that cater to a variety of individual and cultural preferences to encourage more frequent consumption. “[Pulses are] incorporated into marinades, purées, soups, and stews,” Feller says. “I often encourage people to start with flavors that are familiar and branch out to ones that are new.”
Jacobson says, “Swapping in pulses for other ingredients in familiar dishes people regularly consume” offers a realistic path to including more pulses. Examples Jacobson suggests include replacing half or all of the meat for tacos with seasoned lentils, replacing half or all of the ricotta in lasagna with pureed white beans, and replacing up to half the cheese sauce in macaroni and cheese with pureed yellow split peas.
Bottom Line
Plant-focused dietary patterns come in many different forms. Even for people who don’t want to eat exclusively plant foods, pulses play an important role in the DASH, Mediterranean, flexitarian, and other plant-forward diets. Pairing pulses with modest portions of animal foods can enhance nutrient density while reducing food costs.
Clients can add pulses to curries, chili, casseroles, and stir-fries—with or without poultry, seafood, or meat. At breakfast, bean or lentil burritos and tostadas can be a great solution. In addition, clients can blend pulses into smoothies or dips. And roasted pulses, whether store bought or homemade, make healthful snacks or salad toppings.
— Karen Collins, MS, RDN, CDN, FAND, is nutrition advisor to the American Institute for Cancer Research. She offers research reviews on her website (https://karencollinsnutrition.com) and is creator of the Daunting to Doable Nutrition Pro Circle, a membership program for dietitians only.
Resources
The following organizations provide dietitians with recipes, tip sheets, research summaries, and social media inspiration:
• The American Pulse Association: https://pulses.org/us
• Lentils.org (funded by Saskatchewan Pulse Growers): www.lentils.org
References
1. Mitchell DC, Webster A, Garrison B. Terminology matters: advancing science to define an optimal pulse intake. Nutrients. 2022;14(3):655.
2. Didinger C, Thompson HJ. Defining nutritional and functional niches of legumes: a call for clarity to distinguish a future role for pulses in the Dietary Guidelines for Americans. Nutrients. 2021;13(4):1100.
3. Dietary Guidelines for Americans, 2020-2025. U.S. Department of Agriculture and U.S. Department of Health and Human Services website. https://www.dietaryguidelines.gov/. Published December 2020. Accessed July 16, 2023.
4. Lichtenstein AH, Appel LJ, Vadiveloo M, et al. 2021 dietary guidance to improve cardiovascular health: a scientific statement from the American Heart Association. Circulation. 2021;144(23):e472-e487.
5. ElSayed NA, Aleppo G, Aroda VR, et al. 5. Facilitating positive health behaviors and well-being to improve health outcomes: standards of care in diabetes-2023. Diabetes Care. 2023;46(Supple 1):S68-S96.
6. Continuous update project expert report. World Cancer Research Fund/American Institute of Cancer Research website. https://www.wcrf.org/diet-activity-and-cancer/global-cancer-update-programme/global-cancer-update-programme-expert-panel/
7. Rock CL, Thomson C, Gansler T, et al. American Cancer Society guideline for diet and physical activity for cancer prevention. CA Cancer J Clin. 2020;70(4):245-271.
8. Mitchell DC, Marinangeli CPF, Pigat S, et al. Pulse intake improves nutrient density among US adult consumers. Nutrients. 2021;13(8):2668.
9. Marventano S, Izquierdo Pulido M, Sánchez-González C, et al. Legume consumption and CVD risk: a systematic review and meta-analysis. Public Health Nutr. 2017;20(2):245-254.
10. Schwingshackl L, Hoffmann G, Iqbal K, Schwedhelm C, Boeing H. Food groups and intermediate disease markers: a systematic review and network meta-analysis of randomized trials. Am J Clin Nutr. 2018;108(3):576-586.
11. Schwingshackl L, Schwedhelm C, Hoffmann G, et al. Food groups and risk of colorectal cancer. Int J Cancer. 2018;142:1748-1758.
12. Healthy Eating Index. Center for Nutrition Policy and Promotion, USDA Food and Nutrition Service website. https://www.fns.usda.gov/CNPP/healthy-eating-index-hei. Updated July 14, 2023. Accessed July 19, 2023.
13. Morze J, Danielewicz A, Hoffmann G, Schwingshackl L. Diet quality as assessed by the Healthy Eating Index, alternate healthy eating index, dietary approaches to stop hypertension score, and health outcomes: a second update of a systematic review and meta-analysis of cohort studies. J Acad Nutr Diet. 2020;120(12):1998-2031.e15.
14. Petroski W, Minich DM. Is there such a thing as "anti-nutrients"? a narrative review of perceived problematic plant compounds. Nutrients. 2020;12(10):2929.
15. Schlesinger S, Neuenschwander M, Schwedhelm C, et al. Food groups and risk of overweight, obesity, and weight gain: a systematic review and dose-response meta-analysis of prospective studies. Adv Nutr. 2019;10(2):205-218.
16. Kim SJ, de Souza RJ, Choo VL, et al. Effects of dietary pulse consumption on body weight: a systematic review and meta-analysis of randomized controlled trials. Am J Clin Nutr. 2016;103(5):1213-23.