Skip the Juice, Eat Whole Fruits, to Avoid Type 2 Diabetes

It’s tempting to think you can get one of your daily fruit servings from a glass of juice, but skip the convenience of drinking it and instead eat the whole fruit, say Harvard School of Public Health (HSHP) researchers.

Eating more whole fruit—particularly blueberries, grapes and apples—was significantly associated with a lower risk of type 2 diabetes in a recent study. Conversely, greater consumption of fruit juices was associated with a higher risk of type 2 diabetes. The study, published in the online August 29 edition of BMJ (British Medical Journal online, doi:http://dx.doi.org/10.1136/bmj.f5001), is the first to look at the effects of individual fruits on diabetes risk.

“While fruits are recommended as a measure for diabetes prevention, previous studies have found mixed results for total fruit consumption. Our findings provide novel evidence suggesting that certain fruits may be especially beneficial for lowering diabetes risk,” said senior author Qi Sun, assistant professor in the department of nutrition at HSPH and assistant professor at the Channing Division of Network Medicine, Brigham and Women’s Hospital, in Boston.

The researchers examined data gathered between 1984 and 2008 from 187,382 participants in three long-running studies (Nurses’ Health Study, Nurses’ Health Study II and Health Professionals Follow-up Study). Participants who reported a diagnosis of diabetes, cardiovascular disease or cancer at enrollment were excluded. Results showed that 12,198 participants (6.5%) developed diabetes during the study period.

People who ate at least two servings each week of certain whole fruits—particularly blueberries, grapes and apples—reduced their risk for type 2 diabetes by as much as 23% compared with those who ate less than one serving per month. By contrast, those who consumed one or more servings of fruit juice each day increased their risk of developing type 2 diabetes by as much as 21%. The scientists concluded that swapping three servings of juice per week for whole fruits would result in a 7% reduction in diabetes risk.