Fruits have been promoted for their ability to help lower the risk for a number of health conditions. Fruits such as apples, grapes, and blueberries are full of special phytonutrients like flavonoids and anthocyanins that help fight disease at the cellular level. Not only can the vitamins and antioxidants in fruits stave off cancer but researchers at the Harvard School of Public Health think that fruit could play a role in diabetes prevention too.
This is a novel idea given that in the past, fruits have been tagged for raising blood sugar. In order for a food to raise blood sugar, it needs to have a sufficient amount of carbs. Carbohydrates can include both sugar and starches. Fruits definitely fall into the former category as they contain natural fruit sugars. Depending on which fruits you eat and how much—you can cause your blood sugar levels to increase.
Nevertheless, the Harvard researchers found that certain fruits had a beneficial effect on blood glucose levels. The researchers looked at data from almost 200,000 patients who had participated in three long-term health studies: the Nurses’ Health Studies I and II, and the Health Professionals Follow-up Study. At the outset of these three studies, anyone who had diabetes, heart disease, or cancer was excluded from participating. Subsequently, 12,198 people developed diabetes during the trials.
The research team was able to determine overall fruit consumption for the nearly 13,000 diabetics. They then looked at individual fruit consumption to find out how often the participants ate peaches, pears, plums, grapes, bananas, apples, oranges, grapefruit, strawberries, and blueberries. The researchers found that people who ate at least two servings a week of blueberries, grapes, and apples managed to lower their risk for type 2 diabetes by almost 25% when compared with those who only ate fruit once per month.
On the other hand, for those who drank fruit juice, the statistics were not so rosy. Participants who drank juice once a day increased their chances of getting diabetes by 20%. If a participant switched three servings of fruit juice for whole fruits every week, they could drop their diabetes risk by about seven percent.
The researchers chocked up this disparity between fruit juice and whole fruits to the fact that whole fruits also contain fiber which slows down the passage of fruit sugar in the body. Fruit juice moves relatively quickly through the digestive system and can result in a spike in blood sugar.
Why were whole blueberries, grapes, and apples particularly good for lowering diabetes risk? The researchers theorized that the fruits’ anthocyanins likely played a beneficial role.
Looking for another food good at lowering diabetes risk? How about walnuts? Researchers at the Harvard School of Public Health used the same Nurses’ Health Studies to look at the effects of walnut intake and diabetes onset. They found that total nut consumption was associated with a lower risk for diabetes, significantly so when walnuts were consumed.
Source(s) for Today’s Article:
“Eating whole fruits linked to lower risk of Type 2 diabetes,” Science Daily web site, Aug. 30, 2013; http://www.sciencedaily.com/releases/2013/08/130829214603.htm?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+sciencedaily%2Ftop_news%2Ftop_health+%28ScienceDaily%3A+Top+News+–+Top+Health%29; last accessed Aug. 31, 2013.
Pan, A., et al., “Walnut consumption is associated with lower risk of type 2 diabetes in women.” J Nutr. Apr 2013; 143(4): 512-8.
Wedick NM et al, “Dietary flavonoid intakes and risk of type 2 diabetes in US men and women.” Am J Clin Nutr. 2012;95:925-33.