An apple a day may keep the doctor away, but for women, eating berries three times a week may keep the cardiologist at bay.
A large new study that followed nearly 94,000 young and middle-aged women for 18 years found that those who ate three or more servings of blueberries and strawberries a week had a 32 percent lower risk of heart attack. The women, ages 25 to 42, were registered with the long-running Nurses' Health Study II. They completed questionnaires about their diet every four years.
The study was conducted by scientists from the Harvard School of Public Health and the University of East Anglia, United Kingdom, and published this month in the American Heart Association's journal, Circulation.
The researchers were interested in whether a type of antioxidant called anthocyanins - which give berries their intense color - are good for the heart. Previous research had indicated that they may help dilate arteries, counter the buildup of plaque and provide other cardiovascular benefits, according to the study. The researchers chose strawberries and blueberries because they're the most commonly consumed.
During the course of the study, there were 405 heart attacks. However, women who ate the most blueberries and strawberries had a lower risk of heart attack by about a third when compared with women who ate the berries once a month or less - even in women who otherwise ate a diet rich in other fruits and vegetables.
The berry benefit was also found regardless of other risk factors, including age, high blood pressure, family history of heart attack, body mass, exercise, smoking, and caffeine or alcohol intake, researchers said.
To put things in perspective, the study found about a 0.5 percent chance of a heart attack among the participants, and eating berries reduced that to about 0.35 percent. But even though the actual drop in heart attacks was small, "We have shown that even at an early age, eating more of these fruits may reduce risk of a heart attack later in life," said lead author Aedín Cassidy, a researcher at the University of East Anglia.
Or, as senior author Eric Rimm of Harvard's School of Public Health told the Los Angeles Times, "This simple dietary change could have a significant impact on prevention efforts."
Although strawberries and blueberries are some of the best sources of anthocyanins, Cassidy said the powerful compounds are also found in high amounts in cherries, grapes, eggplant, black currants, plums and raspberries.
The study only found an association between berry consumption and lowered heart attack risk; the findings don't explain exactly how berries work to improve heart health. On the other hand, it's berries! They're delicious. Consider it health advice that's easy to swallow.