Long-term benefit of dietary sodium reduction for cardiovascular disease seen in study on prevention of high blood pressure.

BMJ - People who restrict the amount of salt in their diet could reduce their risk of developing cardiovascular disease by 25 percent, according to a report from the British Medical Journal.

Researchers in Boston also found a reduction in salt intake could lower the risk of death from cardiovascular disease by up to a fifth.

Cardiovascular disease refers to a group of illnesses involving the heart or arteries, such as a stroke or heart disease. While there is already a substantial body of evidence showing that cutting back on salt can lower blood pressure, studies showing subsequent levels of cardiovascular disease in the population have been limited and inconclusive.

This research provides some of the strongest objective evidence to date that lowering the amount of salt in the diet reduces the long term risk of future cardiovascular disease, say the authors.

Researchers followed up participants from two trials completed in the 1990s that had been conducted to analyze the effect that reducing salt in the diet had on blood pressure.

All the participants had high-normal blood pressure (pre-hypertension). They were therefore at greater risk of developing cardiovascular disease. 744 people took part in the first Trial of Hypertension Prevention which was completed in 1990. 2382 people participated in the second, which ended in 1995. In both trials participants reduced their sodium intake by approximately 25% to 35% alongside a control group who did not cut back on their salt intake.

The reduction in the chances of developing cardiovascular diseases as a result of the sodium reduction intervention was substantial. The results showed these pre-hypertensive individuals were 25 percent less likely to develop cardiovascular illness over the course of the 10 to 15 years post-trial. There was also a 20 percent lower mortality rate.

To the authors knowledge this sodium restriction study is the first and only study of sufficient size and duration to assess the effects of a low salt diet on cardiovascular disease based on randomized trial data. It provides unique evidence that lowering salt in the diet might prevent cardiovascular problems years later (Courtesy of EurekAlert!, a service of AAAS).