Fruits Fight Diabetes
Many studies have attempted to document the impact of individual dietary components on the risk of conditions like heart disease, stroke and type 2 diabetes. For instance, numerous studies have concluded that higher intakes of fruits and vegetables are associated with a reduced risk of diabetes. Type 2 diabetes is characterized by insulin resistance and abnormally high blood sugar levels.
A new study published in the influential British Medical Journal addressed the question of specific foods. Investigators wondered if a diet enriched with all types of fruits and fruit juices is protective against diabetes, or if certain fruits are more helpful than others. They also wondered if benefits could be attributed to specific components, such as dietary fiber or vitamins. Numerous similar studies have concluded that diets featuring higher intakes of fruits, vegetables and whole grains are protective against the development of type 2 diabetes, compared to diets that do not feature these foods. But results have often been inconclusive or contradictory.
Using data gathered from more than 180,000 men and women over the course of one to two decades, investigators concluded that greater overall consumption of fruits was associated with a mildly reduced risk of type 2 diabetes. Fruit JUICE consumption, though, was linked to a GREATER risk of diabetes. But certain fruits, such as blueberries, apples, grapes, bananas and grapefruit, were found to be especially protective. Investigators speculate that antioxidant compounds in these fruits account for their ability to affect blood sugar regulation.
Interestingly, the glycemic index, or glycemic load values, of individual fruits was not linked to their ability to prevent diabetes. Glycemic index is a measure of how quickly a given food raises blood sugar levels. There is a general assumption that higher glycemic index foods, which rapidly boost blood sugar levels (and thus insulin levels) are more likely to promote diabetes and other illnesses. The present study suggests this is not true regarding whole fruits.
Muraki I, Imamura F, Manson JE, Hu FB, Willett WC, van Dam RM, Sun Q. Fruit consumption and risk of type 2 diabetes: results from three prospective longitudinal cohort studies. BMJ. 2013 Aug 28;347:f5001. doi: 10.1136/bmj.f5001.
Jenkins DJ, Srichaikul K, Kendall CW, Sievenpiper JL, Abdulnour S, Mirrahimi A, et al. The relation of low glycaemic index fruit consumption to glycaemic control and risk factors for coronary heart disease in type 2 diabetes. Diabetologia. 2011 Feb;54(2):271-9. doi: 10.1007/s00125-010-1927-1. Epub 2010 Oct 27.