< Back to All Press

New Study Shows Polyphenol-Rich Diet Has Potential to Safeguard Athletes from Illness

Study Examined the Possibility of Reducing Virus Infections in Long-distance Runners and Other Elite Athletes

Portland, Maine — OCTOBER 30, 2014 — A new study has found that a polyphenol-rich diet containing blueberries and green tea has the potential to protect athletes from virus infections following intense periods of exercise. It is well established that prolonged and intensive exercise, such as marathon running, increases the risk and severity of viral infections in athletes. The findings of this new study, published in Phytotherapy Research, are encouraging news to long-distance runners and other elite athletes.

“Colds and the flu are something that we can’t do much about, and if you have a virus, antibiotics just won’t work. But if there’s an intervention that can help prevent those challenging conditions, then that’s a beautiful thing,” says Dr. Mary Ann Lila, co-author of the study and director of Plants for Human Health Institute at North Carolina State University. Dr. Lila is a widely published research scientist whose work is aimed at identifying bioactive compounds and understanding how they work in the body. She is particularly interested in compounds that appear to counteract chronic disease and promote endurance.

It is not clearly understood why elite athletes are more susceptible to illness following intense exercise, but Dr. Lila confirms that flu-like symptoms and diminished resistance to viruses are familiar nuisances for athletes. The new study was conducted on the blood serum of elite long-distance runners supplemented with a blueberry-green tea-polyphenol-soy protein complex. “What we found was that after the supplement, the athletes’ blood was more resilient and the virus did not have the upper hand,’ notes Dr. Lila.

Dr. Lila notes that the new study confirms that antioxidant-rich polyphenols, which occur abundantly in green tea and blueberries, but are not widely bio-available, are actually pulled into the blood stream through exercise. A polyphenol is a phytochemical that is known to prevent or neutralize the damaging effects of free radicals. “A big takeaway of this study is the evidence that your doctor was actually right—diet and exercise do and in fact must go together. In order to get the good stuff out of your food your body needs to move,” says Lila.

“This study helps reaffirm the nutritional merit of blueberries in general, and also emphasizes the growing research interest in the diverse polyphenol content of blueberries,” notes Kitty Broihier, MS, RD, LD, a nutrition advisor to the Wild Blueberry Association of North America. “Wild Blueberries are a rich source of polyphenols, and factors that impact their bioavailability is an area of ongoing research that will likely have far-reaching implications in many areas of health,” adds Susan Davis, MS, RD, also a nutrition advisor to the Association.

About the study

The study was a partnership between two North Carolina universities and was conducted during the winter and spring of 2012. The research was conducted by faculty of Appalachian State University in Boone, North Carolina, and took place at the Plants for Human Health Institute at the University of North Carolina Research Campus in Kannapolis. Subjects included 38 healthy, non-smoking long-distance runners (both male and female) ages 19-45 years, who regularly competed in marathon and half-marathon road races and were capable of running 2.5 hours at high intensity on laboratory treadmills. During the study, subjects consented to train normally, maintain weight and avoid the use of medications known to affect inflammation and immune function for the duration of the study. All vitamin and mineral supplements above 100% the U.S. Daily Value were also avoided.

Runners were randomized and divided into three groups over a 17-day period using double-blinded methods and a parallel group design. Supplementation took place over a 17-day period, including a 14-day pre-exercise period, followed by a 3-day intensified exercise period. In the study, human cells were grown in a culture and then injected with a virus (vesicular stomatitis), which is known to lead to flu-like symptoms in humans. Then, the athletes’ serum was co-incubated with those cells.

The serum of the athletes who received the blueberry-green tea-polyphenol-soy protein complex supplements showed dramatically reduced viral replication, in contrast to the serum of those in the placebo group, which displayed higher viral replication. And, the virulence of the virus was dramatically lessened when the virus was exposed to the serum of the polyphenol-consuming athletes.

An abstract of the study can be found here.

About the Wild Blueberry Association of North America

The Wild Blueberry Association of North America (WBANA), founded in 1981, is a trade association of growers and processors of Wild Blueberries from Maine and Canada, dedicated to bringing the Wild Blueberry health story and unique wild advantages to consumers and the trade worldwide. WBANA is dedicated to furthering research that explores the health potential of Wild Blueberries and since 1997, has hosted the Health Research Summit in Bar Harbor, a worldwide gathering of scientists and researchers whose work is leading the way in learning more and more about the health benefits of Wild Blueberries. For news, recipes, and related health information about Wild Blueberries, visit www.wildblueberries.com. For the latest updates, read our blog. Visit us on Facebook or on Twitter.