Health: Lower salt intake helps patients on antihypertensive medications

A low-salt diet can significantly reduce blood pressure.

Health: Lower salt intake helps patients on antihypertensive medications

A low-salt diet can significantly reduce blood pressure. This even applies to people who are already taking medication to lower blood pressure. This is the result of an American study with 213 participants between the ages of 50 and 75.

The blood pressure-lowering effect (mean arterial pressure) occurred in around three quarters of the test subjects after just one week and was independent of age, gender, ethnic group, body mass index and diabetes. The team led by Norrina Allen from Northwestern University in Chicago presents their study in the journal “Jama”.

High blood pressure is the leading cause of illness and death worldwide, according to the university. "High blood pressure can lead to heart failure, heart attacks and strokes because it puts extra strain on the arteries," says Allen. Although it was previously known that the consumption of table salt (sodium chloride) influences blood pressure, there were still open questions about the exact connection. "We didn't know whether people who were already taking blood pressure medication could actually lower their blood pressure more by reducing their sodium levels," Allen explains.

Findings from the investigations

In their research, the study authors primarily determined the amounts of sodium a person consumed. About a quarter of the participants had normal blood pressure, the others had high blood pressure that was either controlled, uncontrolled or untreated. The mean (median) age was 61 years, and 65 percent of the test subjects were female. The median systolic blood pressure (the higher value when measuring blood pressure) was 125. The median daily sodium intake was 4.45 grams, which is well above the World Health Organization (WHO) recommended value of two grams of sodium (just under five grams of salt). lies.

The researchers divided the subjects into two groups: Participants in one group were first given a diet containing 2.2 grams of sodium per day in addition to their usual salt intake. Those in the other group were only allowed to consume a total of 0.5 grams of sodium in one day. After a week, the diet plan was changed.

At the end of the first week, the mean systolic blood pressure value in the participants on the low-salt diet was eight millimeters of mercury lower than in the subjects on the high-salt diet. There was no statistically clear connection with the original blood pressure value or the blood pressure status (high pressure, normal pressure). The second week showed a similar result. The blood pressure of the participants who had now consumed little sodium was on average seven millimeters of mercury lower than the others.

Study results not surprising

With the high-salt diet, systolic blood pressure increased only minimally; The researchers suspect a saturation effect here. 9.9 percent of participants reported mild side effects such as headaches, gastrointestinal symptoms and edema. Most of the participants also tolerated the low-salt diet well.

Eight percent reported mild events such as temporary cramps and weakness. "Just as for most people any physical activity is better than none, for most people any sodium reduction from the usual diet is probably better than none when it comes to blood pressure," says Deepak Gupta of Vanderbilt University Medical Center in Nashville, lead author of the study .

For Markus van der Giet from the Charité Berlin, President of the German Hypertension League since the beginning of the year, the study results come as no surprise: "In everyday clinical practice, it is known that some patients with mild high blood pressure can do without antihypertensive drugs when switching to a low-salt diet." In general, however, a low-salt diet cannot replace medication, especially since the daily value of just 0.5 grams of sodium used in the study is very difficult to achieve in everyday life. Nevertheless, reducing salt is an important measure that high blood pressure patients can easily implement, emphasizes van der Giet.