Legume Intake Helps Maintain Healthy Blood Sugar Levels

by | Jul 2, 2008 | 2008, Blood Sugar, Diabetes, Pancreatic Health, Whole Foods - General

Written  by Greg Arnold, DC, CSCS. Researchers found that those with the highest total legume intake had a 49% reduced risk of Type 2 diabetes. With soybean intake, those with the highest intake had a 55% reduced Type 2 diabetes risk. 

Type 2 diabetes currently affects over 18 million Americans (1) and costs our healthcare system more than $132 billion per year (2). Having type 2 diabetes leads to many different health problems, including heart disease and stroke, high blood pressure, blindness, kidney disease, nervous system disease, amputations, dental disease, and even complications during pregnancy (1). As a result, finding ways to minimize these health complications after diabetes has been diagnosed is a priority.

Now a new study (3) has found that helping maintain healthy blood sugar levels may lie in increasing legume intake.

Legumes, which include beans, lentils, peanuts, peas, and soybeans, are good sources of fiber and have a low glycemic index. An animal study has shown that soy helps reduce serum insulin and insulin resistance (4). Building on these findings, over 64,000 women from the Shanghai Women’s Health Study (5) completed a food frequency questionnaire (FFQ) between 1997 and 2000, as well as a follow-up survey between 2000 and 2002 (6) and a questionnaire on physical activity (7). They also had physical examinations that included weight, height, hip/waist circumference, and body mass index (BMI).

The researchers found that those with the highest total legume intake (65 grams per day) had a 49% reduced risk of Type 2 diabetes, compared to those with the lowest intake (12 grams per day). With soybean intake, those with the highest intake (32 grams per day) had a 55% reduced Type 2 diabetes risk, compared to those with the lowest intake (3 grams per day). Soy milk consumption of 214 grams per day elicited a 46% reduced risk of Type 2 diabetes, compared to not consuming soy milk. Finally, consuming 46 grams per day of soy protein per day produced a 50% reduced risk of Type 2 diabetes, compared to consumption of only 17 grams per day.

When suggesting the mechanism by which increased legume intake led to healthier blood sugar levels, the researchers pointed to increased fiber content in the diet (8), a lower glycemic index (9), and the polyphenols such as isoflavones and lignans found in legumes “which have an antioxidant effect and may be responsible for the protective role of legumes against the development of type 2 Diabetes.” Finally they suggested that soy protein has an effect on insulin secretion and increasing fat breakdown in the liver and fat cells (10).

Even peanuts had a significant effect on Type 2 diabetes risk. Those with the highest intakes (3 grams per day) had a 32% reduced risk, compared to those with the lowest intake (0.1 grams per day).

All of these results led the researchers to conclude that this study “adds to evidence that shows a beneficial effect of the consumption of legumes in the development of T2D.”

Source: Villegas, Raquel, et al. “Legume and soy food intake and the incidence of type 2 diabetes in the Shanghai Women’s Health Study.” The American journal of clinical nutrition 87.1 (2008): 162-167.

© 2008 American Society for Nutrition

Posted July 2, 2008.

References:

  1. “National Diabetes Statistics” posted on National Institute of Diabetes and Digestive and Kidney Diseases website.
  2. Economic Cost of Diabetes, 2002. Diabetes Care 2006;26(3): 917
  3. Villegas R. Legume and soy food intake and the incidence of type 2 diabetes in the Shanghai Women’s Health Study. Am J Clin Nutr 2008 87: 162-167
  4. Bhathena SJ, Velasquez MT. Beneficial role of dietary phytoestrogens in obesity and diabetes. Am J Clin Nutr 2002;76(6):1191–201.
  5. Zheng W, Chow WH, Yang G, et al. The Shanghai Women’s Health Study: rationale, study design, and baseline characteristics. Am J Epidemiol 2005;162(11):1123–31
  6. Shu XO, Yang G, Jin F, et al. Validity and reproducibility of the food frequency questionnaire used in the Shanghai Women’s Health Study. Eur J Clin Nutr 2004;58(1):17–23.
  7. Matthews CE, Shu XO, Yang G, et al. Reproducibility and validity of the Shanghai Women’s Health Study physical activity questionnaire. Am J Epidemiol 2003;158(11):1114–22.