Diet Seen as a Key to Health in Elderly
Many older adults can maintain normal blood pressure and reduce their need for antihypertension medications by losing weight and reducing salt intake--effectively reversing a lifetime of bad eating habits--according to the first major study of such lifestyle changes in an aging population.
Several earlier studies have shown that high blood pressure in younger people can be controlled by changes in diet. But until now, it has never been clear that those findings could be extrapolated to the elderly.
Two of every three Americans over 60 have high blood pressure, and more than half of those take costly and sometimes risky antihypertension drugs.
The new study, reported today in the Journal of the American Medical Assn., found that more than half of the elderly patients who achieved a 25% reduction in salt intake and a weight loss of as little as eight pounds could stop taking blood pressure medications.
“One of the most remarkable things about this study is that people maintained their weight loss or low-sodium diet for at least 2 1/2 years,” said Dr. Walter H. Ettinger Jr. of Wake Forest University. Younger people are much less successful in maintaining such objectives.
“This is good news for older Americans with hypertension who may be unaware of the impact of modest lifestyle changes,” said Dr. Claude Lenfant, director of the National Heart, Lung and Blood Institute.
The results are particularly important because older people are already at higher risk for heart attack and stroke, according to the American Heart Assn. “While you can’t control getting older, you can control your diet,” said Dr. Theodore Kotchen of the association’s nutrition committee.
And by reducing blood pressure, the elderly reduce the risk of stroke and heart disease, he said.
The kidneys of the elderly don’t work as well as those of younger people, making it more likely that they will retain salt and water, said Dr. Paul Whelton of the Tulane University School of Public Health and Tropical Medicine, who headed the new study. The elderly’s metabolism is different, and their arteries are less flexible.
“We couldn’t easily translate the [previous] findings in younger people to older groups,” he said.
In the new study, called the Trial of Nonpharmacological Interventions in the Elderly, researchers at four centers recruited 975 hypertensive people between the ages of 60 and 80 who were being treated with an antihypertension drug.
The 390 who were not overweight were assigned to either counseling in salt reduction or no treatment. The 585 who were overweight received either counseling in salt reduction alone, counseling in weight reduction alone, counseling in both salt and weight reduction, or no treatment.
After three months, patients were carefully weaned from blood pressure medication. Those whose blood pressure remained normal were kept off the drugs, while those whose blood pressure rose were returned to treatment.
In the sodium reduction group, 31% were able to stay off medication. In the weight reduction group, 36% were able to stay off. And among those who reduced their weight and salt intake, “a whopping 53%" were able to stop taking drugs, Whelton said.
Many who could not drop the drugs completely were able to get by on lower doses. Some antihypertension medications have been linked to an increased risk of heart attacks. Others cause sexual dysfunction, shortness of breath and lack of energy.
The study was not large enough to determine whether the healthier diet would prevent heart disease and strokes, Whelton said, “but the trends suggest that it does.”
The healthier diet would probably have many other beneficial effects that were not studied, Whelton said. Similar diets have been shown to reduce high levels of cholesterol, another important cause of heart disease. “We would also anticipate a reduction in the likelihood of diabetes, arthritis, breast cancer and osteoporosis,” he said.
The success of the study will provide “a fresh stimulus for renewed efforts to control and end the high blood pressure epidemic,” Dr. Jeremiah Stamler of the Northwestern University Medical School in Chicago wrote in an accompanying editorial in the journal.
Stamler and others noted that physicians must make a much greater effort to counsel elderly patients about the benefits of a healthy diet.
The ability of the subjects to maintain the reduced weight and sodium intake throughout the 30-plus months of the trial was particularly impressive. “There was very little recidivism, which is usually the Achilles’ heel of these trials,” Whelton said.
In similar hypertension studies of people in their 30s and 40s, he said, about 60% of subjects maintain their objectives for six months. But by the end of three years, the success rate is down to 20%.
But the elderly, he said, “have more time, have more money and see a lot more [illness] around them. Typically, we see that older individuals are better at adhering to any medical recommendations.
“And these results say to older people that, no matter what you have done earlier in life, you can have a pretty good impact on your health with only modest changes in lifestyle.”
The recommended diet, Stamler said, is high in fruits and vegetables, legumes and whole grains, fat-free and low-fat dairy products, poultry, fish and shellfish. It is reduced in salt, total fat, saturated fat and cholesterol, with no more than one or two alcoholic drinks per day and controlled in calories to correct obesity.
“Not everyone is going to be able to get along without [antihypertension] drugs,” Whelton said. “But the fundamental approach should be a change in lifestyle.”