Cut Hypertension Drugs With Low-Salt Diet
Study Shows Low-Salt Diet Reduces Need for Blood Pressure Medication
Salt and Blood Pressure: Across Populations
In another study in the same issue, U.K. researchers found that a modest reduction in salt intake reduces blood pressures in Asians, blacks, and whites."The vast majority of previous studies have only been in white subjects," study co-author Graham A. MacGregor, MD, professor of cardiovascular medicine at St. George's, University of London, tells WebMD.
This study tested the impact of salt reduction in 169 men and women, ages 30 to 75, who had mild high blood pressure but weren't on blood pressure medications. They reduced salt from an average of 9.7 grams a day to 6.5. That translates to dropping sodium intake from about 3,800 milligrams a day to about 2,400 milligrams, according to MacGregor. (Salt is different than sodium. Salt is about 40% sodium; the rest is chloride.)
At the study start, participants had an average blood pressure of 147/91. After being on the low-salt diet, their blood pressure dropped to an average of about 141/88.
''There were other benefits of salt reduction other than blood pressure," MacGregor tells WebMD. They found less calcium in the urine when the low-salt diet was followed. Over the long haul, reducing calcium loss through the urine would be expected to reduce osteoporosis risk. They also found less albumin in the urine. High levels of albumin in the urine can signal kidney damage and indicate a higher risk of cardiovascular disease.
"Some people have a bigger fall [in blood pressure] than others," MacGregor says. But salt reduction, he adds, will benefit everyone. "Even if you have very low blood pressure, you are less likely to get osteoporosis."
High blood pressure affects more than 1 billion people worldwide. Even modest reductions in blood pressure readings would be expected to have a large impact on rates of blood-pressure-related diseases such as heart attack and stroke when spread over such a large population.
While the study of those with resistant hypertension included only a dozen patients, the reduction in blood pressure was "striking," says Lawrence J. Appel, MD, MPH, a professor of medicine and epidemiology at the Johns Hopkins School of Medicine and School of Public Health in Baltimore. He wrote an editorial for the journal.
The blood pressure drop seen in the Pimenta study, according to Appel, is equivalent to what would be expected if two more blood-pressure-lowering medications were added.
The study of those with mild high blood pressure, Appel tells WebMD, points out not only that different ethnic groups can benefit from lowering salt, but that salt reduction has effects beyond blood pressure, such as potential protection from kidney and heart disease.
Reducing salt, he says, will not be easy for many Americans. He suggests first buying lower-salt breads and cereals and limiting consumption of processed foods such as luncheon meats, which have high amounts of salt.
"However, if we are to succeed at lowering sodium consumption as a society, ultimately significant changes will need to be made in our food supply," he writes.
A co-author on the Pimenta study has served as a consultant for the Salt Institute; Appel has received research grants from King-Monarch Pharmaceuticals, which makes a blood pressure-lowering medicine.