A new study published October 22 in the Archives of Internal Medicine, a journal of the American Medical Association, has found that type 2 diabetes patients who consumed at least one cup of legumes (such as beans, chickpeas or lentils) per day significantly improved their glycemic (blood sugar) control and also reduced their risk of heart disease through lower blood pressure.
The study, conducted by David J.A. Jenkins, M.D., of the University of Toronto and St. Michael’s Hospital, Toronto, Canada, and colleagues, compared the results of a diet of increased legume consumption with a high-fiber diet, and found the increased legume consumption more beneficial to both glycemic control and heart disease risk for patients with type 2 diabetes.
Low glycemic index (GI) foods have been associated with improvement in glycemic control in patients with type 2 diabetes and have been recommended in many national diabetes guidelines, the authors wrote in the study background. This study affirms those recommendations with respect to legumes.
The study appears online in the October 22, 2012 issue of the Archives of Internal Medicine, doi:10.1001/2013.jamainternmed.70, a journal of the American Medical Association.
The Study; Method
The researchers conducted a randomized controlled trial of 121 patients with type 2 diabetes melitus to test the effect of eating more legumes on glycemic control, serum (blood) lipid levels and blood pressure.
The study participants were randomly assigned for a three-month trial period to either a legume diet that increased their consumption of legumes by at least one cup per day or to a high insoluble fiber diet that increased their consumption of whole wheat products.
Blood tests were taken at the beginning and end of the trial period to measure for changes in hemoglobin A1c (HbA1c) values. Based on this measure, the researchers also calculated cardiovascular disease (CHD) risk scores for each patient at the beginning and end of the study period.
“Glycated hemoglobin or glycosylated hemoglobin (hemoglobin A1c, HbA1c, A1C, or Hb1c; sometimes also HbA1c) is a form of hemoglobin that is measured primarily to identify the average plasma glucose concentration over prolonged periods of time,” and is one of the criteria used in the diagnosis of diabetes and in monitoring of blood glucose levels in patients with diabetes, according to the 2010 American Diabetes Association Standards of Medical Care in Diabetes.
In diabetes mellitus, higher amounts of glycated hemoglobin, indicating poorer control of blood glucose levels, have been associated with cardiovascular disease.
The researchers found that the low-glycemic legume diet reduced HbA1c values by -0.5 percent and the high wheat fiber diet reduced HbA1c values by -0.3 percent.
The low-GI legume diet reduced cardiovascular disease (CHD) risk by -0.8 percent, compared with a reduction in CHD risk in the high wheat fiber diet of -4.5 mm Hg, the authors calculated.
The greater reduction in CHD risk associated with the legume diet was largely because of a greater relative reduction in systolic blood pressure on the legume diet, the researchers reported.
“In conclusion, legume consumption of approximately 190 g per day (1 cup) seems to contribute usefully to a low-GI diet and reduce CHD risk through a reduction in BP,” the authors wrote.
“These findings linking legume consumption to both improved glycemic control and reduced CHD risk are particularly important because type 2 DM [diabetes melitus] is increasing most rapidly in the urban environments of populations in which bean intake has traditionally been high (e.g. India, Latin America, the Pima Indians of Arizona),” the authors conclude.
“Support for the continued use of such foods in traditional bean-eating communities, together with their reintroduction into the Western diet, could therefore be justified even if the effect on glycemia is relatively small, given the magnitude of the problem and the need for acceptable dietary options, especially those options that may also have a BP and cardiovascular advantage.”
In invited commentary submitted by Marion J. Franz, M.S., R.D., C.D.E. of Nutrition Concepts by Franz Inc., Minneapolis, Minn., and published by the Archives of Internal Medicine with the new study, Mr. Franz writes, “The importance of the glycemic index (GI) and fiber in diabetes mellitus (DM) nutrition therapy has been controversial.”
“Legumes, as documented in the study by Jenkins et al, are components of a healthy eating pattern for people with DM and the general public. Whether people with DM can eat the amount necessary to improve glycemic control is debatable, and, if legumes do improve glycemia, is it because of their low GI or high soluble fiber content?” the commentary further states.
“Nutrition therapy for DM is effective. However, just as there is no one medication or insulin regimen appropriate for all persons with DM, there is no one nutrition therapy intervention. A variety of nutrition therapy interventions have been shown to be effective. Nutrition education and counseling must be sensitive to the personal needs and cultural preferences of individuals and their ability to make and sustain lifestyle changes,” Franz concludes.
The new study report was published online October 22, 2012 in the (Archives of Internal Medicine, doi:10.1001/2013.jamainternmed.70.
The commentary was published along with the study appears in the (Archives of Internal Medicine. Published online October 22, 2012, doi:10.1001/2013.jamainternmed.871.
For information on a healthy diet, exercise and other lifestyle factors that promote wellness and prevent diseases, see the HelpingYouCare® resource pages on Wellness/ Healthy Living for Seniors & Caregivers, including:
- Diet & Nutrition: Physical Wellness;
- Exercise: Physical Wellness;
- Sleep, Hygiene, Quit Smoking & Other Healthy Practices: Physical Wellness;
- Activities to Preserve Mental Acuity: Intellectual Wellness;
- Social Interaction & A Sense of Connection With Others: Social Wellness;
- Other Areas of Wellness: Emotional, Ethical/ Spiritual & Vocational Wellness; and
- Healthy Living: Stories of Inspiring Seniors.
Copyright © 2012 Care-Help LLC, publisher of HelpingYouCare®. All rights reserved.
NOTICE: If you are reading this article on any website other than HelpingYouCare.com, please click HERE to go to the original article. No website other than HelpingYouCare® has been given permission to publish this article.