Recent years have seen a trend away from reliance on drugs in the treatment of certain chronic disease. Instead, emphasis has shifted to dietary and other therapies.

Drugs can have unpleasant side effects, in some cases can themselves cause further complications, and are sometimes expensive for the patient. These and other issues can make the long-term compliance necessary to control a condition through medication difficult to achieve.

In the case of high blood pressure, alternative treatment may offer hope. The results of a study published in the Journal of the American Medical Association indicate that some hypertensives may be able to withdraw from drug therapy in favor of dietary changes.

Dr. Herbert Langford and colleagues at the University of Mississippi Medical Center, in collaboration with researchers from Albert Einstein College of Medicine in New York and the Universities of Alabama and Texas, set up the study to answer three critical questions. Could long-term antihypertensive therapy "cure" hypertension? That is, could patients whose blood pressure was under control with drug treatment be taken off medication and maintain normal blood pressure without further intervention? Would sodium restriction coupled with an increase in potassium intake improve the chances for successful withdrawal from drug therapy? Finally, what contribution could weight reduction make toward maintenance of normal blood pressure after drug treatment was stopped?

The study involved 496 individuals. All had been on antihypertensive medication for at least five years and their blood pressures had remained normal for at least one year. Those of normal weight were divided into two groups. One group was gradually withdrawn from medication and no dietary intervention was prescribed. The other was withdrawn from medication and placed on sodium restriction and increased potassium intake.

Subjects more than 20 percent over their ideal weight were put either in one of the two groups or in a third set, where medication was withdrawn and a calorically restricted diet was given with no change in sodium or potassium intake. The study lasted 56 weeks. Blood pressures were monitored at regular intervals.

At the study's end, only 35 percent of the overweight subjects not on sodium and potassium modifications or weight-reducing diets still had normal blood pressure. By comparison, 60 percent of those who had lost weight were able to maintain normal blood pressure. It was the best success rate among all the groups. Weight loss averaged 10 pounds, but showed great variation. Interestingly, those on calorically restricted diets who had to be put back on medication lost less weight, although the difference was not considered statistically significant.

The next most successful group contained those who were not overweight and had followed diets lower in sodium and higher in potassium. More than half of this group still maintained normal blood pressure.

A more dramatic effect was seen among study participants classified as mild hypertensives. Those not overweight who were getting less sodium and more potassium had a 78 percent success rate. Seventy-two percent of subjects on the weight-reduction program had normal blood pressure when the study ended.

What do these findings imply? It seems that for some individuals who have been on long-term antihypertensive therapy, treatment can be discontinued for at least one year, indicating that the drugs have somehow altered the mechanisms controlling blood pressure. Half of the mild hypertensives in this study remained unmedicated without any modification of sodium or potassium intake or weight reduction.

Of course, the study lasted only one year. It remains to be determined whether normal blood pressure can be maintained over a longer period. In fact, throughout the study there was a steady decline among all groups in the number of individuals who maintained normal blood pressure. This suggests that the beneficial effects may be time-limited.

Are these findings applicable to the general public? In an accompanying editorial, Walter Flamenbaum and Neill Cohen of the Beth Israel Medical Center in New York caution that the participants in this study may not be entirely typical of other hypertensives. All had previously taken part in a drug-intervention study lasting five years -- a commitment indicating a high degree of motivation. In addition, the number of clinic visits built into the study was much more frequent that would normally occur, providing extra reinforcment. For some people, remembering to take a pill once a day is difficult enough; changing one's eating habits can be a still greater challenge.

What's encouraging, however, is that a large weight loss was unnecessary before success rates increased (although presumably the weight must be kept off to maintain the effect). It looks as if reasonable nutrition interventions may modify the need for drug therapy -- at least in some cases.