Fruit juice tied to modest rise in diabetes risk

By Anne Harding

NEW YORK (Reuters Health) - Women wanting to ward off type 2 diabetes should load their plates with green leafy vegetables and whole fruits, but perhaps stay away from fruit juice, new research suggests.

Eating an additional three servings of whole fruit daily, or one more serving of spinach, kale or similar leafy green vegetable was tied to a lower risk of developing diabetes over an 18-year period among 71,346 women enrolled in the Nurses' Health Study.

"It was a modest decrease," Dr. Lydia A. Bazzano of Tulane University School of Public Health and Tropical Medicine, New Orleans, told Reuters Health. "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."

Bazzano and colleagues analyzed data on the diets of Nurses' Health Study participants -- 4,529 of whom developed type 2 diabetes while they were being followed. They divided women into five groups based on fruit and vegetable intake, and also grouped them based on fruit juice consumption.

They found that an increase of three servings a day of whole fruit was associated with an 18 percent lower risk of type 2 diabetes, while a single additional serving of leafy green vegetables cut the risk by 9 percent. However, an additional daily serving of fruit juice increased the likelihood of developing diabetes by 18 percent.

While the findings must be replicated, Bazzano said, there are plausible mechanisms by which fruit juice could increase risk. "It's a big sugar load and it comes in a liquid form which is absorbed rapidly," she noted.

The findings, the study team concludes, suggest 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."

SOURCE: Diabetes Care, July 2008.