What’s the Skinny on Vegetables, Fruits and Fats?

This article was originally published in the Westfield Leader on July 10, 2014. 

In my last Westfield Leader article, I noted that clinical studies do not support any significant medical health benefits or harm of multivitamins. Unfortunately, the same holds true with antioxidant- rich vegetables and fruits. At the recent American Association for Cancer Research meeting with close to 20,000 attendees, unlike in the past, reports on diet and dietary supplements were virtually absent. Dr. Walter Willet, a well respected Harvard epidemiologist and strong advocate of the beneficial role of diet in maintaining health, reported that, regarding cancer, there is little solid clinical evidence that vegetables and fruits are protective. Though he didn’t address their role in other diseases, the same currently holds true.

So here we are: multivitamins, vegetables and fruits with medical-health benefits unknown. As I’ve repeatedly stressed before, long term clinical nutritional studies, unlike those with insulin or penicillin, are difficult to execute with precision. In the past, there was an explosion of highly promising, but not definitive, clinical studies supporting the benefits of diets and dietary supplements. This rapidly resulted into the creation of a huge nutrition industry propelled by vast armies of media. I, myself, was cautiously optimistic. After all, many scientific laboratory studies supported these clinical results. Americans, with evangelical fervor, eagerly embraced not only products supported by these studies but others which were not. This pattern still holds.

During the 90’s, motivated by these promising clinical studies, my foundation sponsored multiple nutraceutical conferences in Manhattan and Washington, D.C. with some of the world’s most respected leaders in nutrition and clinical research to encourage more clinical research on nutritional products. A nutraceutical, the term I coined, is a nutritional product that has been proven to have a medical-health benefit in a well-designed clinical study.

There then followed a surge in such studies most of which, unfortunately and surprisingly, reported negative results, including those on herbal remedies. Because of the magnitude and the level of emotional zeal of the players in the nutrition field, and I don’t say this with cynicism or disrespect, the current disappointing clinical data on vegetables and fruits will not be given the sufficient attention that they deserve. In fact, media coverage of the negative results has already virtually vanished. Nutritional advocates will continue to embrace their ersatz gods of broccoli, kale and fruit-vegetable salads, be it in their educational efforts or at the dinner table.

Highly questionable favorable reports will continue to raise false hope. For example, one study reports that eating five or more servings of produce daily decreases the risk of heart disease by 30 percent. The World Cancer Research Fund in conjunction with the American Cancer Institute report that certain vegetables may help to protect against multiple cancer types. I can assure you that neither study could withstand statistical scrutiny.

It’s worthwhile to note that at The American Association for Cancer Research meeting a reception was hosted by M.D. Anderson, one the world’s foremost medical centers for cancer research, where thick slabs of roast beef and all kinds of cheeses were served followed by a buffet of rich fat-laden desserts. This was before the recent publication in the Annals of Internal Medicine reported that saturated fats may not be harmful which I’ll discuss in my next Leader article.

So what’s the true skinny on the medical-health benefits and risks of vegetables and fruits? As with multivitamins, the clinical data regarding both benefits and harm are not definitive, and we just don’t know. Until such time, be very skeptical of any health-medical claims- and there will be many.

Stephen L. DeFelice, M.D.