Saturday, November 22, 2008
Whole Fruit and Green Leafy Vegetable Decrease Risk of Diabetes
Eating as little as one more serving of green leafy vegetables or three more servings of whole fruit per day can significantly decrease the risk of developing Type 2 diabetes, according to a study conducted by researchers from Tulane University School of Public Health and Tropical Medicine and published in the journal Diabetes Care.
Researchers followed 71,346 women who were taking part in the Nurses' Health Study for 18 years. They found that eating just one more serving of green leafy vegetables per day decreased the chance of developing diabetes by 9 percent, while an additional three servings of whole fruit per day cut the risk by 18 percent.
"It was a modest decrease," researcher Lydia A. Bazzano said. "This is not going to ... prevent it if you have many, many risk factors and you're overweight ... it's a tool in the prevention strategy."
Surprisingly, the researchers found that it was only whole fruits that decreased the risk of diabetes; fruit juices actually increased it. Just one more serving of fruit juice per day led to an 18 percent increase in the risk of diabetes.
The study could not determine why fruit juices and whole fruits would cause such different effects. Researchers speculated that the sugars in juice are more quickly absorbed the bloodstream, leading to a spike in blood sugar - and thereby insulin.
"It's a big sugar load," Bazzano said, "and it comes in a liquid form, which is absorbed rapidly."
In contrast, the high fiber content of whole fruits might cause the sugar to be digested more slowly.
The researchers advised that "caution should be observed in replacing some beverages with fruit juices in an effort to provide healthier options. The same caution applies to the recommendation that 100 percent fruit juice be considered a serving of fruit, as it is in the present national dietary guidelines."