Women should start adding more tomato products to their diets, according to the results of a study presented this week by Harvard Medical School researchers at the American College of Cardiology annual meeting.
The study, compiled from data from the Women's Health Study, suggests that lycopene, an antioxidant in tomatoes, may reduce the risk of heart disease in middle-aged and older women by as much as 33 per cent, reports the Vitamin Nutrition Information Service (VNIS).
The study, conducted by Harvard Medical School researchers at Brigham and Women's Hospital in Boston, analysed blood samples of nearly 500 women from the Women's Health Study who developed cardiovascular disease and an equal number of women from the study who did not develop the disease.
After the researchers took into account coronary risk factors, such as history of high cholesterol and physical inactivity, they found that those women with the highest levels of plasma lycopene (the level of lycopene found in the blood) had a 33 per cent lower risk of developing cardiovascular disease than those with the lowest levels. The researchers believe that the level of lycopene in the blood is related to the amount of lycopene consumed in the diet.
"This is the first large-scale study to examine the role that lycopene may play in reducing the risk of cardiovascular disease exclusively in women," said lead researcher Howard D. Sesso, instructor of medicine at Harvard Medical School and director of epidemiology at Brigham and Women's Hospital. "The body of research on lycopene in other conditions such as prostate cancer is more advanced, but the 33 per cent risk reduction in our study has compelled us to further investigate lycopene's power in combating heart disease."
Other studies have identified a correlation between lycopene and a reduced risk for cardiovascular disease, the VNIS said. Several epidemiological studies have found a potential benefit of lycopene in cardiovascular disease risk reduction in men or in both men and women.
The multi-centre European Study of Antioxidants, Myocardial Infarction and Cancer of the Breast (EURAMIC) examined the association between antioxidant concentration in fat tissue and the incidence of myocardial infraction (MI) in 10 countries. The study found that men with the highest concentrations of lycopene in their fat tissue had a 48 per cent reduction in risk for developing cardiovascular disease when compared to men with the lowest lycopene levels in their fat tissue.
Other research, the Kuopio Ischaemic Heart Disease Risk Factor study, found that low serum lycopene concentrations were associated with a three-fold increased risk of acute coronary events such as heart attack and stroke.
Scientists and health professionals have long recommended increasing fruit and vegetable intake as part of a heart healthy diet, in part because of their high antioxidant content.
"There are no dietary recommendations for lycopene. Yet the research suggests that women should aim to consume more lycopene-rich foods as a prudent measure in the prevention of chronic diseases," commented Michael Gaziano, director of cardiovascular epidemiology at Brigham and Women's Hospital and one of the study's authors. Dietary sources of lycopene include tomato-based products such as tomato soup, pizza sauce and fruits such as watermelon and pink grapefruit.
"The findings from our study will add to the body of scientific literature on lycopene and a reduced risk of cardiovascular disease," said Dr Sesso. "Later this year, we'll continue to add to that body of research by examining blood levels of lycopene in men. In addition, we'll look at dietary intakes of lycopene and its impact on the risk of cardiovascular disease."