Blueberries have earned their reputation as a superfruit in part because of their high content of antioxidant polyphenols. (In fact, of course, theres no such thing as a superfruit-all fruits have some super qualities.) New research put those polyphe-nols to the test against metabolic syndrome, a complex of conditions, including central obesity (high waist-hip ratio), high blood pressure, high serum cholesterol and insulin resistance, that increases the risk of heart disease and diabetes.Arpita Basu, PhD, RD, of Oklahoma State University, and colleagues conducted a ran-domized controlled trial using 48 participants, mostly women, with metabolic syndrome. The subjects, average age 50, were all obese, with a very high average body mass index (BMI) of almost 38. Over eight weeks, participants daily consumed either a beverage containing 50 grams of freeze-dried blueberries or an equivalent amount of plain water. Arpita Basu, PhD, RD, of Oklahoma State University, and colleagues conducted a ran-domized controlled trial using 48 participants, mostly women, with metabolic syndrome. The subjects, average age 50, were all obese, with a very high average body mass index (BMI) of almost 38. Over eight weeks, participants daily consumed either a beverage containing 50 grams of freeze-dried blueberries or an equivalent amount of plain water. Tested at the four- and eight-week marks, the blueberry-supplemented group showed greater decreases in systolic and diastolic blood pressure. Participants consum-ing the blueberry beverage also saw greater decreases in plasma oxidized LDL (the bad cholesterol) levels and markers of oxidative stress. Other blood lipid levels and glucose concentration were not affected.Basu and colleagues concluded, Our study shows blueberries may improve selected features of metabolic syndrome and related cardiovascular risk factors at dietary achiev-able doses. The amount studied equaled under two ounces of freeze-dried blueberries.
| Blueberries may also be good for your brain. Animal studies at Tufts have shown the polyphenols in blueberries reverse age-related declines in the brains ability to process information, as well as cognitive and motor deficits. This pioneering work was led by James Joseph, PhD, who passed away this spring. |
A second new study, conducted with mice, adds to the evidence that blueberries may have cardiovascular benefits. Xianli Wu, PhD, of the USDA Arkansas Childrens Nutrition Center and University of Arkansas for Medical Sciences, and colleagues fed mice either a control diet or a diet containing 1% freeze-dried blueberries for 20 weeks. As is common in artery research, the mice were bred to be deficient in apoE, a protein that works in the liver on fats such as triglycerides.Researchers found that mice on the blue-berry diet showed protective effects against atherosclerosis-clogging of the arteries due to a buildup of plaques, usually from choles-terol. The blueberry-fed mice also had better measures of antioxidant and enzyme activity related to the heart and arteries.While needing to be confirmed in humans, the results suggest a protective effectiveness of blueberries against atherosclerosis, accord-ing to Wu and colleagues.TO LEARN MORE: Journal of Nutrition, September 2010; abstracts at jn.nutrition.org/cgi/content/abstract/140/9/1582?etoc and jn.nutrition.org/cgi/content/abstract/140/9/1628?etoc.