Whole Fruit is Better Than Fruit Juice
Replace apple and grape juice with “real” fruit when possible? Here is a resolution that could limit the risk of diabetes. This is suggested by a new study from the Harvard School of Public Health, published online in the British Medical Journal.
Fruits are foods rich in fiber, polyphenols and antioxidants. Consumption of fruit by diabetics is a controversial issue, with some doctors considering that they are a source of sugar.
In this new study, the researchers wanted to compare the fruits between them, but also the consumption of whole fruits to that of fruit juice. For this, they used the data collected in three large prospective studies: Nurses ‘Health Study, Nurses’Health Study II and Health Professionals Follow-up Study . Between 1984 and 2008, among more than 187,000 people followed, approximately 12,000 developed type 2 diabetes.
In all three cohorts, fruit consumption was associated with age, physical activity, multivitamin use or fruit juice consumption. After adjusting for different factors such as lifestyle, consuming 3 whole fruits a week had no significant effect on the risk of diabetes: the risk was only slightly reduced. On the other hand, this risk decreased for some fruits: each time we eat 3 more servings a week, the risk of diabetes is reduced by 26% for blueberries, 12% for grapes and 11% for plums.
The benefits of fruits on the body can come from their constituents (vitamins, polyphenols, potassium, magnesium…). Regular consumption of fruits and vegetables is recommended to prevent various chronic diseases. Recently, it has been shown that a Mediterranean diet, rich in fruits and vegetables, combined with a low glycemic load, reduces the risk of diabetes.
But do fruit juices have the same effect as whole fruits? When researchers looked at fruit juices, they found that an increase of 3 servings a week increased the risk of diabetes by 8%. Conversely, when we replace 3 servings of fruit juice with whole fruits, the risk of diabetes decreased by 7%; this percentage was even 19% for grapes, 14% for apples and pears and 12% for grapefruit.
These observations can be explained by the glycemic index, which indicates the speed with which a food raises the glucose concentration in the blood. Indeed, compared to fruits, fruit juices are quickly digested; they have a higher glycemic index than whole fruits which are higher in fiber. In general, the more a carbohydrate food is processed, the more its glycemic index increases.
According to other studies, still conducted at Harvard, fruit juices and sodas would have a responsibility in early mortality from diabetes, cancer and cardiovascular disease.
Practical conclusion : It is sometimes said that a fruit equals a fruit juice; it is not correct. Whenever possible, it is good to focus on whole fruits. But we can of course continue to enjoy the fruit juices, in moderation. The idea is to consume more whole fruits than fruit juice in the week.
Muraki I, Imamura F, Manson JE, Hu FB, WC Willett, van Dam RM, Sun. BMJ.2013 Aug 28; 347: f5001. doi: 10.1136 / bmd.