Beans really may be a magical fruit -- a new study in the journal Archives of Internal Medicine shows that for Type 2 diabetes patients, the more legumes you eat, the better your glycemic control and the lower your risk of coronary heart disease.

"We know from our previous research that foods low on the glycemic index scale are helpful in lowering blood glucose levels," study researcher Dr. David Jenkins, director of the St. Michael's Hospital's Risk Factor Modification Centre, said in a statement. "But this is the first study of its kind to specially look at legumes' effect on cardiovascular risk factors and find they also have a blood pressure lowering effect in diabetic patients."

The study was funded by the Agricultural Bioproducts Innovation Program, via the Saskatchewan Pulse Growers and the Pulse Research Network (PURENet). The authors have also worked for, been part of, or received grants in the past from a number of agriculture groups and food companies.

Researchers found specifically that eating about a cup a day of legumes (190 grams) -- which include beans, peas and lentils -- is linked with lower blood pressure levels, which is important because "blood pressure is a big contributor to renal failure in these patients," Jenkins said in the statement.

The study included 121 people with Type 2 diabetes, whose measurements -- including blood pressure, blood fat, blood glucose and hemoglobin A1C levels (which determines diabetes control) -- were taken at the start of the study. Then, for three months, some of the participants ate a low-glycemic index diet, as well as one cup more per day of legumes, while others ate a healthy diet with whole-wheat foods to boost their intake of insoluble fiber.

Then, the participants' measurements were taken again at the end of the study period. While the whole-wheat group experienced benefits in blood fat, blood glucose and hemoglobin A1C levels, the legume group experienced benefits in all these groups plus blood pressure.

Legumes are considered very low-glycemic foods. The glycemic index, which was developed by Jenkins, is used to determine the level at which a food will spike blood sugar levels. For example, foods like white bread are high on the glycemic index scale because they cause blood sugar levels to rise; apples and legumes are low on the scale because they tend to stabilize levels. (For more on what the glycemic index is, click here.)

However, in a related commentary published in the same journal, Marion J. Franz of Nutrition Concepts by Franz Inc. noted that the role of a low-glycemic index on diabetes has been controversial, with some recent studies showing that there may not be a difference in low-glycemic index and high-glycemic index diets in hemoglobin A1C levels.

However, Franz noted, legumes are known to be part of a healthy diet -- the question is just whether legumes seem to have this benefit for diabetes patients because of its low glycemic index status, or because legumes are high in soluble fiber.

Franz wrote:

Nutrition therapy for DM is effective. However, just as there is no 1 medication or insulin regimen appropriate for all persons with DM, there is no 1 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.

These findings come out at the same time as a new study in the journal Circulation, showing that more adults in the U.S. are getting their blood pressure levels under control -- 47 percent in 2010, compared with 29 percent a decade ago.

So besides being linked with lower blood pressure, not to mention their awesome protein and fiber contents, what are some other health benefits of beans? Click through the slideshow to find out.

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  • Lower Prostate Cancer Risk

    A 2000 study in the <a href="http://cebp.aacrjournals.org/content/9/8/795.full">journal <em>Cancer Epidemiology, Biomarkers & Prevention</em></a> showed that legumes, yellow-orange vegetables and cruciferous vegetables are linked with a lower risk of prostate cancer. The study, which included more than 1,600 men, didn't show a link between tomatoes and fruits and prostate cancer risk, though.

  • Decrease Diabetes Risk

    A study of more than 64,000 middle-aged Chinese women showed that <a href="http://www.ncbi.nlm.nih.gov/pubmed/18175751">eating legumes</a> -- especially soybeans -- is linked with a decreased risk of Type 2 diabetes. The study, published in 2008 in the <em>American Journal of Clinical Nutrition</em> showed that the more legumes a woman ate, the lower her risk of diabetes.

  • Help Your Heart

    The more beans you eat a week, the lower your risk of heart disease. At least that's the finding of a 2001 study in the <em>Archives of Internal Medicine</em>, showing that eating legumes at least four times a week <a href="http://www.ncbi.nlm.nih.gov/pubmed/11718588">reduces coronary heart disease risk</a> 22 percent more than eating legumes fewer than one time a week. The findings are based on 9,632 people who were part of the First National Health and Nutrition Examination Survey Epidemiologic Follow-up Study.

  • Lower Risk Of A Precursor To Colorectal Cancer

    A number of studies has shown a link between legume consumption and a lower risk for colorectal adenomas, which are known to be a precursor for colorectal cancer. One study, published in 2006 in the <em>Journal of National Black Nurses' Association</em>, showed that <a href="http://www.ncbi.nlm.nih.gov/pubmed/17410754">eating legumes</a> -- like lentils, split peas and dried beans -- is linked with a lower risk of colorectal adenomas in African-American adults. And in a 2006 study in the <em>Journal of Nutrition</em>, researchers found that people who <a href="http://jn.nutrition.org/content/136/7/1896.full">added the most dried beans</a> to their diets had a lower risk of recurrence of advanced colorectal adenomas, compared with those who ate the fewest dried beans.

  • Get Your Cholesterol Under Control

    Eating beans every day could help to <a href="http://www.ars.usda.gov/is/pr/2007/071128.htm">lower total cholesterol levels</a>, according to a <em>Journal of Nutrition</em> study. The U.S. Department of Agriculture reported that all it takes is eating a half-cup of cooked dry beans daily. The study included 80 adults -- with ages ranging from 18 to 55 -- who were either healthy or who were at risk for metabolic syndrome. Half of the study participants ate the beans for 12 weeks, while the other half had chicken soup for 12 weeks. By the end of the study period, people who ate the beans had lower cholesterol than those assigned to eat the chicken soup, the USDA reported.

  • Could Keep Your Brain Sharp

    A study published this year in the <em>Journal of Nutrition, Health and Aging</em> showed that eating fewer legumes and vegetables is linked with a <a href="http://www.ncbi.nlm.nih.gov/pubmed/22659995">higher risk of cognitive decline</a> among elderly Chinese people who are illiterate, compared with those who ate more vegetables and legumes. The research included analysis of 5,691 people ages 65 and older who were illiterate and part of the Chinese Longitudinal Health Longevity Study.

  • The Nutrition Benefits of Legumes

    Wellness Director for Sodexo’s School Services, Roxanne Moore, shares the secret behind legumes health benefits.