Attention heart patients
According to a report, a moderate diet does not reduce cholesterol unless it is supplemented with exercise. Studies have shown that a healthy bloodstream carries low levels of "bad" cholesterol or low-density lipoprotein (LDL) and high levels of "good" cholesterol or high-density lipoprotein (HDL). Ultra low-fat diets reduce LDL but also drag down HDL. So Marcia Stefanick and colleagues at Stanford University in Palo Alto, California, USA, looked to see what dieting and exercise could do for people facing the risk of heart disease. Volunteers were divided into four equally-sized groups - first assigned to diet only, second to exercise only, third to both diet and exercise, and fourth to neither. The diet was moderate, less than 200 milligrams of cholesterol per day with seven per cent of calories coming from saturated fat as compared to about the average 12 per cent of calories from unsaturated fats. The exercise regimen was equivalent to 10 miles of brisk walking. The researchers found that while levels of HDL cholesterol did not change much in any group, levels of LDL cholesterol dropped by about nine per cent m women and by 13 per cent in men who both exercised and dieted, compared to those who did neither. Stefanik concludes that the present guidelines for controlling cholesterol which place too much emphasis on diet and not enough on exercise need revision.