The antioxidants, magnesium, and fiber of vegetables may reduce the risk of developing type-2 diabetes by up to 30 per cent, according to a widely publicized study coming from China.
The study, published in the March 2008 edition of the Journal of Nutrition, tracked the eating habits of 64,191 women aged 40 to 70 in China. Food choices were tracked at the beginning of the study and four-and-a-half years later, and rates of diabetes compared.
Researchers measured intakes of cruciferous vegetables (bok choi, brussels sprouts, broccoli, cabbage, kale, mustard greens, turnip greens, and winter radish), other green leafy vegetables, yellow vegables, onions and garlic, tomatoes, and other vegetables. They also measured consumption of fruit.
The quintile of women eating the most vegetables--an average of 428 grams (nearly a pound) a day--was 28 less likely to become diabetic than the quntile of women eating the least--121.5 grams, or only about 1/4 pound a day. Eating more fruit did not reduce the risk of developing type-2 diabetes.
No particular vegetable stood out as diabetes-protective. The researchers believe that fiber, antioxidants, and magnesium in vegetables may all play an important role in preventing the disease. Generally speaking, vegetables are both relatively low-carb and low-fat, making them useful in almost any diet for weight loss or diabetes prevention. Some vegetables such as broccosprouts seem to have special protective properties, but these veggies are eaten in small amounts almost medicinally.
The authors of the study also pointed out that vitamin C and vitamin E are also known to influence blood glucose levels. Even antioxidant like DHEA may play a role in the ongoing health of people with type-2 diabetes.
And because the study, jointly conducted by the Shanghai Cancer Institute and the Diabetes Research and Training Center in Nashville, Tennessee, only looked at diets of women in China, it is possible the results are not exactly applicable to other populations.
Still, this study is strong evidence that getting a full nine servings of vegetables a day may protect against developing diabetes type-2.