Whole fruits linked to lower diabetes risk, while fruit juices may increase risks: Harvard study
The new research, published in the BMJ, used data from three large scale prospective longitudinal cohort studies to determine whether individual fruits are differentially associated with risk of type 2 diabetes. It is the first study to investigate how individual fruits might affect diabetes risk.
Led by senior author Qi Sun from the Harvard School of Public Health, USA, the research team analysed data from more than 180,000 people - consisting of more than 3,400,000 person years of follow up - examine the associations of individual fruit consumption in relation to risk of type 2 diabetes.
" Moreover, we estimated substitution effects of individual fruits for fruit juice in relation to risk of type 2 diabetes," explained the researchers.
" Greater consumption of specific whole fruits, particularly blueberries, grapes, and apples, is significantly associated with a lower risk of type 2 diabetes, whereas greater consumption of fruit juice is associated with a higher risk," they said.
Indeed, 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% in comparison to those who ate less than one serving per month.
Conversely, 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%, revealed Sun and colleagues.
The team suggested that swapping three servings of juice per week for whole fruits would result in a 7% reduction in diabetes risk.
"While fruits are recommended as a measure for diabetes prevention, previous studies have found mixed results for total fruit consumption," said Sun.
"Our findings provide novel evidence suggesting that certain fruits may be especially beneficial for lowering diabetes risk."