Specific whole fruits (particularly blueberries) are significantly associated with a lower risk of type 2 diabetes. Fruit juice, on the other hand, is linked to a greater risk.
The daily whole fruit and fruit juice consumption of 187382 participants (who were free of major chronic diseases at baseline) was analyzed over nearly 3.5 million person-years of follow-up to determine the association between certain fruits and the risk of type 2 diabetes.
The Study: The subjects were drawn from the Nurses’ Health Study (1984-2008; N=121700), Nurses’ Health Study II (1991-2009; N=116671) and the Health Professionals Follow-up Study (1986-2008; N=51529). Participants completed questionnaires every 4 years. To account for other variables, a follow-up questionnaire was administered eery 2 years for updates on anthropometric and lifestyle factors, including body weight, height, cigarette use, physical activity, and family history of diabetes. The follow-up rate was 90%.
- Dietary modifications among other lifestyle changes prevent development of type 2 diabetes
- Whole fruits contain more phytochemicals, fiber, and antioxidants (and thus more health benefits) than fruit juice.
- Blueberries significantly decrease the risk of developing type 2 diabetes.
- Fruit juice significantly increase the risk of developing type 2 diabetes.
For individual fruits, the pooled hazard ratios of type 2 diabetes for every three servings/week were 0.74 for blueberries; 0.88 for grapes and raisins; 0.89 for prunes; 0.93 for apples and pears; 0.95 for bananas and grapefruit; 0.97 for peaches, plums, and apricots; 0.99 for oranges; 1.03 for strawberries; and 1.1 for cantaloupe.
My Take: This study adds to the literature showing benefits to consuming whole fruits and vegetables. Prior studies have been inconsistent in linking fruit consumption and a decreased risk of diabetes. Get the fruit through whole foods, rather than juices. And certain fruits, including blueberries, may be better than others. Cantaloupe may increase risk among men who consume i more than once per month. Glycemic index did not predict which fruits reduced risk. Finally, fruit juice consumption does not reduce the chances of getting diabetes.
What You Should Consider: Aim for 5 vegetables and fruits daily. But remember, not all have similar safety profiles. The so-called Dirty Dozen (best to eat organic, if possible) include: Apples, celery, cherry tomatoes, cucumbers, grapes, hot peppers, nectarines, peaches, potatoes, spinach, strawberries, and sweet bell peppers. The Clean Fifteen include: Asparagus, avocado, cabbage, cantaloupe, sweet corn, eggplant, grapefruit, kiwi, mangos, mushrooms, onions, papayas, pineapple, sweet peas, and sweet potatoes. This list is from the Environmental Working Group.
I’m Dr. Michael Hunter, and I have a handful of blueberries next to me as I write this blog!
The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.
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References: Integrative Medicine 16(12), December 2013; British Medical Journal 2013;347:f5001.