A clinical trial of the American Heart Association step one diet for treatment of hypercholesterolemia.

BACKGROUND

Although diet therapy is the primary treatment for hypercholesterolemia, a trial to determine the effectiveness of the new American Heart Association Step One Diet (AHA diet) in lowering cholesterol has to our knowledge never been carried out.

METHODS

A clinical trial was conducted to assess the plasma lipids response and adherence to the AHA diet in 120 men and women with hypercholesterolemia. All subjects were advised to follow the AHA diet for 18 weeks.

RESULTS

After 6 weeks of the AHA diet intervention, there were modest but significant reductions in plasma total cholesterol (-2.6%) and low-density lipoprotein (LDL) cholesterol (-3.5%), but no further significant reductions were observed thereafter. Rather, there was a tendency to return to and even exceed baseline levels of total cholesterol and LDL cholesterol over the subsequent 12 weeks, in spite of the subjects' reported continued adherence to the AHA diet and maintenance of weight loss throughout the entire study period. Nevertheless, 51% of the subjects had experienced improvement (-0.2% to -26.3%) in their plasma LDL cholesterol levels by the end of the study.

CONCLUSIONS

A probable reason for the limited response of the diet was low baseline levels in intake of saturated fat and cholesterol by participants. The subjects who were older and had higher levels of plasma LDL cholesterol and total fat intake at baseline experienced better plasma LDL cholesterol response to the AHA diet. Thus, practicing physicians should consider assessing the baseline dietary fat and cholesterol intake of patients with hypercholesterolemia before starting the AHA diet, since patients may already be following a relatively prudent self-selected diet. Additional dietary gains in lipid management might well require a more severe restriction of dietary fats and cholesterol. Long-term efficacy of the AHA diet should also be evaluated clinically with periodic lipid profiles.