Front page headlines in the Baltimore paper - and many others nationwide, I expect - screamed that low-fat diets do not help to prevent heart attacks (or breast or colon cancer) in postmenopausal women.
We need to look beyond the headlines before deciding there are no possible benefits from low-fat diets.
The news reports are based on results from the Women's Health Initiative Dietary Modification Trial, which randomly assigned nearly 49,000 postmenopausal women to eat either a low-fat diet or their usual diet and followed them for an average of 8.1 years.
The women in the low-fat group were asked to reduce total fat to 20 percent of calories and to increase their intake of vegetables, fruits, and grains. The average age of the participants when they entered the study was 62.3 years.
As a group, women on the low-fat diet had no decline in the incidence of coronary artery disease, stroke, or other cardiovascular events. They did show small but statistically significant decreases in body weight, LDL cholesterol, and diastolic blood pressure.
A major problem with the design of the study was that the women were told to lower their total fat intake rather than to modify the types of fat they ingested. As a result, they reduced their intake of cholesterol-lowering mono- and polyunsaturated fats as much as they lowered their intake of cholesterol-raising saturated fats.
In fact, those women who decreased their intake of saturated and trans fats the most, and who ate the most vegetables and fruits, did show a trend toward less coronary heart disease.
Can we expect that eight years of following an even better-designed low-fat diet could overcome the ill effects of following an improper diet for more than 50 years?
Despite its limitations, the study's outcome is disappointing for those of us who have been advocating and following a proper cholesterol-lowering diet.
I hope the results will not discourage you from limiting your intake of saturated and trans fats and cholesterol, from replacing saturated fats with mono- and polyunsaturated fats as much as possible, from losing weight if necessary, and from increasing your intake of vegetables and fruits.
