(NaturalNews) Younger women who eat more strawberries and blueberries may reduce their heart attack risk by one-third, according to a study conducted by researchers from the Harvard School of Public Health, the University of East Anglia, United Kingdom, and published in the journal Circulation.
"Blueberries and strawberries can easily be incorporated into what women eat every week," senior author Eric Rimm said. "This simple dietary change could have a significant impact on prevention efforts."
In part because the risk of heart attack is fairly low in young and middle-aged women, little research has been conducted into the specifics of risk and prevention in this population. Smoking and oral contraceptive use are known to raise heart attack risk among young and middle-aged women, but the effect of diet is mostly unknown.
The current study was carried out on 93,600 women between the ages of 25 and 42 who were taking part in the Nurses' Health Study II. Each participant completed a dietary questionnaire once every four years over the course of 18 years. During this time period, 405 heart attacks occurred among the participants.
The researchers found that women who ate the most strawberries and blueberries (three or more servings per week) had a 32 percent lower risk of heart attack than women who ate those berries once a month or less. This effect was true even after the researchers adjusted for other risk factors, including age, weight, exercise, family history of heart attack, high blood pressure, smoking, caffeine or alcohol intake, and even diet.
In other words, even among the sample of women that had a diet high in fruits and vegetables, women who ate the most strawberries and blueberries were still less likely to have a heart attack.
"We have shown that even at an early age, eating more of these fruits may reduce risk of a heart attack later in life," lead author Aedin Cassidy said.
The power of anthocyanins
The study focused on blueberries and strawberries because they are the most common types of berries consumed in the United States. Berries are known to be high in naturally occurring plant chemicals known as flavonoids, specifically the group known as anthocyanins. Numerous studies have linked flavonoids to a number of health benefits, and anthocyanins in particular have been shown to help dilate arteries, prevent the buildup of arterial plaque, and provide other benefits to the cardiovascular system.
Other foods high in flavonoids include blackberries, cherries, black currants, grapes, red wine, eggplant, plums and raspberries.
Upon further analysis, the data seemed to suggest that a higher anthocyanin intake was associated with a lower risk of heart attack. This correlation was not found with other varieties of flavonoid.
"Growing evidence supports the beneficial effects of dietary flavonoids on endothelial function and blood pressure," the researchers wrote, "suggesting that flavonoids might be more likely than other dietary factors to lower the risk of [coronary heart disease] in predominantly young women."