Environmental Nutrition
By Jill Weisenberger, M.S., R.D.N., C.D.E.
As if you need another reason to fill your plate with more plants! But new research suggests that diets rich in polyphenols, a large class of compounds found in foods of plant origin, may fend off type 2 diabetes, and help those who already have diabetes better manage their blood sugar.
More than 26 million Americans have type 2 diabetes. One in four don’t know they have it. Another 86 million adults have prediabetes, and about 90 percent are unaware. Both disorders are characterized by insulin resistance, which causes higher-than-normal blood sugar levels. Polyphenols, found in plant foods, may help people with diabetes — and those at risk for type 2 diabetes — by reducing insulin resistance, acting as antioxidants, and tamping down inflammation. Polyphenols consist of several classes and subclasses. One large class of polyphenols is flavonoids, which includes several subclasses, such as anthocyanidins, found in red, purple, and blue plant foods, like blueberries and purple potatoes, and flavanols, found in such foods as tea, wine and cocoa.
The evidence
In a study of more than 100,000 health professionals in the U.S., researchers found that eating blueberries, apples and pears (rich in anthocyanidins) was linked to lower risk of developing type 2 diabetes. Finnish researchers also found that blueberries were related to less risk of the disease.
Another study suggested that flavonoids in cocoa make some cells in the body less resistant to the effects of insulin. And tea, which is high in flavonoids, is linked with lower blood glucose levels in people over the age of 65 years.
Finally, a study of 86 overweight or obese adults at risk for metabolic syndrome found that individuals assigned to eat a diet rich in polyphenols for eight weeks showed less oxidative stress and lower blood triglyceride levels than people who consume a diet low in polyphenols. However, we need more research to confirm the protective effects of polyphenol intake on type 2 diabetes.
Bottom line
It’s unclear if polyphenols specifically help prevent or manage diabetes. It’s possible that other components in these same foods exert the health-boosting effects. Or perhaps the benefit of eating fruits, vegetables and other foods containing polyphenols is that they replace less wholesome foods in the diet. Regardless, there are lots of benefits to plant-centric eating.
(Reprinted with permission from Environmental Nutrition, a monthly publication of Belvoir Media Group, LLC. 800-829-5384. www.EnvironmentalNutrition.com.)
