James Joseph, PhD, a nutrition researcher at the Human Nutrition Research Center on Aging at Tufts University, begins his days by drinking a glass of pomegranate juice and eating a cup of wild blueberries. According to a 2008 article in Psychology Today, after studying blueberries, otherwise known as Vaccinium, for years, Dr. Joseph is convinced that they help the brain and the body fight the seemingly endless number of problems associated with aging. While blueberries contain traditional nutrients, such as carbohydrates, fiber, vitamins C and E, and manganese, they also have anthocyanidins (dark flavonoid phytochemicals), which fight oxidative stress and inflammation. “Cumulatively, the berries produce antioxidant effects, neutralizing cellular damage created by free radicals of oxygen and blocking pathways by which oxidative stress damages cells. Perhaps more important, they function as anti-inflammatory agents to preserve cardiovascular as well as brain function.
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WALNUTS AND BLUEBERRIES SUPPORT BRAIN NEURONS
In a 2004 interview with the Seattle Post-Intelligencer, Dr. Joseph said that the old neurons in the brain are like couples who have been married a long time-they no longer communicate. Blueberries change that dynamic. They enable neurons to once again converse. “Blueberries have compounds that boost neuron signals and help tum back on systems in the brain that can lead to using other proteins to help with memory or other cognitive skills.”
In his research on rats and mice, Dr. Joseph has found that rats that eat blueberries have fewer cases of Alzheimer’s disease and lower instances of arthritis-related inflammation. He and his colleagues have also determined that blueberries may be useful for those undergoing radiation therapy. They reduce the effects on cognitive and motor skills and may “even eliminate radiation-induced nausea.”3 Rats that were fed a diet containing two per cent blueberry extracts before undergoing radiation did far better than those rats who received no blueberries before their radiation treatments. “Irradiation causes deficits in behavior and signaling in rats which were ameliorated by an antioxidant diet.” Possibly, “the polyphenols in these fruits might be acting in different brain regions.”
Dr. Joseph has observed that blueberries tend to work best when eaten with high-fat foods such as walnuts. Walnuts contain polyphenols and omega-3 fatty acids. Working together, the blueberries and walnuts make nerve cell membranes more responsive. (Nutritional Benefits of Walnuts can be found here.) As a result, “the efficacy of all transactions” is improved. In addition, the combination of blueberries and walnuts “may help block inflammation at the cellular level”. Furthermore, The research points to a process now implicated in cardiovascular disease, Alzheimer’s disease, and other degenerative processes of aging.
A Canadian study lead by Wilhelmina Kalt, PhD, a researcher with Agriculture and Agri-Food Canada, published in 2008 in the British Journal of Nutrition, reported that pigs who were fed a 2-percent blueberry diet experienced reductions of total, LDL, and HDL cholesterol. The two-percent blueberry diet is equivalent to two cups of blueberries in the human diet. Why is this significant? Pigs and humans have similar levels of LDL. They are also prone to diet-related vascular disease and atherosclerotic plaques in the carotid artery and aorta. Furthermore, their heart rate and blood pressure resemble human heart rate and blood pressure6. A 2008 article in Grocer states that as a result of her research, Dr. Kalt advises people to eat at least four ounces of blueberries every day.
In a 2006 study published in the Journal of Agricultural and Food Chemistry, Navindra Seeram, PhD, assistant director of the UCLA Center for Human Nutrition and assistant professor at the David Geffen School of Medicine at UCLA, reported that the extracts of common berries, such as blueberries, which are filled with antioxidants, inhibit the growth of in vitro mouth, prostate, breast, and colon cancer cells. Dr. Seeram and his colleagues also determined that higher amounts of berries inhibit larger numbers of cancer cells. “With increasing concentration of berry extract, increasing inhibition of cell proliferation in all of the cell lines were observed, with different degrees of potency between cell lines.”
Another study, published in 2007 in Clinical Cancer research, describes research conducted by scientists at Rutgers University and the U.S. Department of Agriculture (USDA) on the relationship between pterostilbene, a naturally occurring antioxidant in blueberries, and colon cancer. During the study, rats were given a compound to induce colon cancer. Half of the rats were then placed on a balanced diet; the other half were given the same diet, but it was supplemented with pterostilbene. At the end of eight weeks, the rats were compared to the control group. The rats that had consumed supplemental pterostilbene had 57 percent fewer pre-cancerous colonic lesions. Researchers concluded that the “study suggests that pterostilbene, a compound present in blueberries, is of great interest for the prevention of colon cancer.”
Agnes Rimando, PhD, a researcher with Natural Products Utilization Research in Mississippi, a division of the USDA Agriculture Research Service, has found similar results. In her studies, Dr. Rimando has noted that pterostilbene may well impair the ability of enzymes to activate chemical carcinogens. So cells that might otherwise tum cancerous do not.
ANTI-AGING AND GENERAL WELL-BEING
It has been well established that there is a strong relationship between oxidative stress and chronic illness and aging. Moreover, the antioxidants in blueberries are known to fight that oxidative stress. A research study published in 2007 in the Journal of the American College of Nutrition found that it is not only important for people to eat blueberries and other antioxidant foods. It is also significant when they eat them. To reduce oxidative stress throughout the day, the researchers recommend eating blueberries or other antioxidant foods with each meal.
A 2006 study published in Neurobiology of Aging addressed the fact that as people age, the heat shock proteins in the brain, which, like antioxidants, support healthy brain functions, decline. Could eating blueberries reverse this decline? For ten weeks, researchers fed a blueberry-enhanced diet to both young and old rats. They were then compared to a control group of old rats, who were fed a diet without blueberries.
As expected, after ten weeks the brains of the young rats were found to contain large amounts of heat shock proteins. The brains of the old rats who did not eat blueberries had low amounts of heat shock proteins. However, the heat shock proteins of the old rats who ate blueberries were completely restored. Researchers concluded that blueberries play a serious role in protecting against the neurodegenerative processes associated with aging.
NUTRITIONAL BENEFITS OF BLUEBERRIES
A 2005 article in Nutrition Today summarizes the many reasons for including blueberries in the diet. “The blueberry is becoming more widely recognized for its flavor, nutrition, and health benefits. Both production and consumption in the United States have more than doubled in the last 20 years. Not only are blueberries ranked among the highest in antioxidant activity when compared to other fruits and vegetables, they are also one of the richest sources of anthocyanins.” There is very strong evidence that the consumption of anthocyanins reduces the risk the heart disease, cancer, and other problems associated with aging.