Science is finding more health benefits from blueberriesâ€”but raising more concerns about fruit juice. According to a new study by Harvard University researchers, eating whole fruits helps ward off diabetes, while drinking juice can actually raise the risk of developing the disease.
In a study published in the British Medical Journal, nutrition experts report that consumption of certain fruitsâ€”especially blueberriesâ€”cut peopleâ€™s risk of type 2 diabetes by as much as 26 percent in a survey of more than 180,000 subjects over two and a half decades.
Study participants were asked about their consumption of grapes or raisins, prunes, bananas, cantaloupe, apples or pears, oranges, grapefruit, blueberries, strawberries, and stone fruits (peaches, plums, or apricots).
Blueberries had the strongest effect on cutting diabetes risk, followed by grapes and apples, especially when three or more servings a week were eaten. A standard serving of blueberries was half a cup.
Prunes, pears, bananas, and grapefruit also helped lower diabetes risk, while the other fruits did not.
The difference is something called polyphenols, said study co-author Qi Sun, an assistant professor of nutrition at Brigham and Womenâ€™s Hospital and Harvard Â School of Public Health. Some of these plant-based chemical compoundsâ€”including anthocyanins, chlorogenic acid, and resveratrol, all powerful antioxidantsâ€”may help the body process glucose. Blueberries, grapes, and apples are all rich in these beneficial polyphenols.