American women fail to understand their risk for heart disease and how exercise and body weight influence that risk, according to a recent report by the American Heart Association.
Coronary heart disease, the number-one killer of women in the US, causes more deaths in adults over the age of 25 than the five other leading causes of death combined. In 2003, 6 million women had coronary heart disease and 3.1 million had strokes, leading to 483,300 deaths.1
To study the relationship between obesity, physical activity, and heart disease risk, researchers at the Harvard University School of Public Health followed 88,393 women, ages 34 to 59, in the Nurses’ Health Study for 20 years. None of the women had cardiovascular disease or cancer at the study’s onset.
During the 20 years of follow-up, there were 889 deaths due to coronary heart disease, as well as 1,469 cases of non-fatal myocardial infarction. Analyzing these data, Harvard scientists determined that obesity and being overweight were associated with an increased risk of coronary heart disease, while increasing levels of physical activity were associated with a graded reduction in risk.2
Active women of healthy weight served as a reference group. Women who were both obese and inactive had a 3.4 times greater heart disease risk over 20 years, while women who were active but obese were 2.5 times more likely to have heart disease. Women of normal weight who did not exercise had 1.5 times the risk for heart disease than did lean, active women. Obese, sedentary, smoking women demonstrated the highest risk for coronary heart disease, which was 9.4 times higher than the risk for lean, active, non-smoking women.2
These findings counter some recent studies suggesting that overweight people may avert cardiovascular disease risk by being fit, demonstrating that both fitness levels and weight are independent and important predictors of heart disease risk.2
According to researcher Dr. Frank Hu, “A high level of physical activity did not eliminate the risk of coronary heart disease associated with obesity and leanness did not counteract coronary heart disease risk associated with inactivity.”1
—Elizabeth Wagner, ND