By Brierley Wright, M.S., R.D., July/August 2008
When it comes to health, berries have a fabulous reputation. Blueberries are packed with antioxidants, called anthocyanins, that may help keep memory sharp as you age, and raspberries contain ellagic acid, a compound with anti-cancer properties. All berries are great sources of fiber, a nutrient important for a healthy digestive system. But if you need more reasons to dig into summer’s sun-kissed little fruits, look no further than two new studies, which suggest that berries may be good for your heart and your bones as well.
In a study of 72 middle-age people published recently in the American Journal of Clinical Nutrition, eating just under a cup of mixed berries daily for eight weeks was associated with increased levels of “good” HDL cholesterol and lowered blood pressure, two positives when it comes to heart health. Included in the mix were strawberries, red raspberries and bilberries—similar to blueberries—as well as other berries more common in Finland (where the research was conducted): black currants, lingonberries and chokeberries.
“At the moment we do not know which berry, or berries, could have been the most active,” says Iris Erlund, Ph.D., senior researcher at the National Public Health Institute in Helsinki and lead author of the study. But, in fact, the diverse range of polyphenols—a broad class of health-promoting plant compounds that includes anthocyanins and ellagic acid—provided by the mix of berries is likely responsible for the observed benefits. Polyphenols may increase levels of nitric oxide, a molecule that produces a number of heart-healthy effects. One is helping to relax blood vessels, which subsequently results in lowered blood pressure, says Erlund.
Polyphenols may also help preserve bone density after menopause, according to new research in the Journal of Nutritional Biochemistry. Our bones are constantly “turning over”—breaking down and building back up. After menopause, when estrogen levels plummet, bone breakdown outpaces bone formation, and the result is bone loss, a risk factor for osteoporosis. In the study, rats that had their ovaries removed (to mimic an estrogen-deprived postmenopausal state) and were fed blueberries every day for three months significantly increased their bone density, scientists at Florida Study University discovered. “We believe that polyphenols in the berries slowed the rate [of bone turnover], ultimately saving bone,” says Bahram Arjmandi, Ph.D., R.D., the study’s lead author and professor and chair of the department of nutrition, food and exercise sciences at FSU. More research is needed to know for sure whether the benefits translate to humans but, says Arjmandi, the data suggest that eating even a small amount of blueberries each day—perhaps as little as 1⁄4 cup—could be good for anyone’s bones.
Bottom line: Dig into a variety of berries regularly to reap the “total body” benefits of their polyphenols.