Eating more whole fruits, particularly blueberries, grapes and apples, is linked to a lower risk of type 2 diabetes, according to a new study.

The new research also suggests that a greater fruit juice consumption has an adverse effect on a person's risk of developing the condition. 

Researchers from the UK, USA and Singapore examined the association of individual fruit consumption to type 2 diabetes risk. Data was used from three studies among US adults.

The study included both men and women and ten individual fruits were used: grapes or raisins; peaches, plums or apricots; prunes; bananas; cantaloupe; apples or pears; oranges; grapefruit; strawberries; blueberries. Fruit juice included apple; orange; and grapefruit.

Food frequency questionnaires were used to assess participants' diet, asking how often, on average, they consumed each food in a standard portion size.

Information was gathered on the participants' body height and weight, smoking, physical activity, multivitamin use and family history of diabetes. Information for women was collected on menopausal status, post-menopausal hormone use and oral contraceptive use.

Results showed that 6.5% of the participants developed diabetes. Their total whole fruit consumption correlated positively with age, physical activity, multivitamin use, total energy intake and fruit juice consumption.

Three servings per week of blueberries, grapes and raisins, and apples and pears significantly cut the risk of type 2 diabetes. In contrast, a greater consumption of fruit juice increased the risk.

Replacing three servings per week of fruit juice with individual whole fruits reduced the risk of type 2 diabetes by 7%, with the exception of strawberries and cantaloupe melon.

The study was published in the British Medical Journal online at bmj.com