Eating a diet high in antioxidant-rich vegetables and fruits, like broccoli and apples, can significantly reduce the risk of coronary heart disease in women, but taking single-antioxidant supplements does not have the same effect, a study conducted in Sweden has found.
The study, led by researcher Alicia Wolk of the Institute of Environmental Medicine at the Karolinska Institute in Stockholm, followed 32,561 Swedish women aged 49-83 from September 1997 through December 2007. The women completed a questionnaire in which they were asked how often, on average, they consumed each type of food or beverage during the last year.
The researchers calculated the total antioxidant capacity of the women's diets. Total antioxidant capacity "measures, in one single value, the free-radical-reducing capacity of all antioxidants present in foods" and how the antioxidants work together to protect and promote health, says the study, published in the October edition of the American Journal of Medicine.
The women were then grouped into five categories according to the total antioxidant capacity of their diet. The researchers found that fruit and vegetable consumption was the single largest contributor to the women's antioxidant capacity, providing 44 percent of the total. Other sources of antioxidants were whole grains, coffee and chocolate.
During the study, 1,114 women suffered a heart attack. But women in the high antioxidant capacity group, who consumed on average seven servings a day of fruit and veg, were found to be 20 percent less likely to have myocardial infarction than women in the low fruit-and-veg consumption group, who consumed only around 2.4 servings per day.
Previous studies have not found the same protective benefits from taking antioxidant supplements, Wolk noted. In fact, one study associated high doses of single-antioxidant supplements with higher all-cause mortality, she said.
The Swedish study is the first "to look at the effect of all dietary antioxidants in relation to myocardial infarction," said Wolk.
Because it was conducted on women, it cannot be generalized to men, the researchers said.
They also noted that women who eat an antioxidant-rich diet are more health conscious than their low fruit-and-veg eating counterparts.
But even when the researchers took into account the fact that the high antioxidant group was less likely to smoke, more likely to be physically active, and were around eight percentage points more likely to have a higher education, the results of the study remained "statistically significant," pointing to higher fruit and vegetable consumption as a simple lifestyle choice to keep heart attacks at bay.