Cut down on salt and lower your risk of heart disease

Apr 22 2007

Researchers in the U.S. say those people who significantly cut down on the amount of salt contained in their diet could reduce their chances of developing cardiovascular disease by as much as twenty five percent.

The scientists at Brigham and Women's Hospital and Harvard Medical School in Boston also say a reduction in salt intake could lower the risk of death from cardiovascular disease by up to a fifth.

Dr. Nancy Cook and her colleagues studied more than 3,000 people who took part in a study of a low-salt diet and its effects on high blood pressure and found that those who were assigned to a low-salt diet had a lower risk of all kinds of cardiovascular disease even 10 to 15 years later.

They were also 20 percent less likely to have died than those assigned to a normal diet.

Cardiovascular disease is a group of diseases linked to the heart or arteries, for example a stroke or heart disease and there is already substantial research which demonstrates that cutting down on salt lowers blood pressure.

This latest research however has produced some of the strongest objective evidence yet that lowering the amount of salt in the diet reduces the long term risk of future cardiovascular disease.

The researchers followed up participants included in two trials completed in the nineties conducted to examine the effect that reducing salt in the diet had on blood pressure.

At the outset all the participants had high-normal blood pressure (pre-hypertension) and were therefore at greater risk of developing cardiovascular disease.

In the first Trial of Hypertension Prevention which was completed in 1990, 744 people took part; in the second trial, which ended in 1995, 2382 people took part.

In both trials participants reduced their sodium intake by approximately 25% - 35% in comparison to a control group who did not cut back on their salt intake.

The participants in the earlier trials provided detailed information about cardiovascular and other health problems and the researchers found that participants who had cut back on salt during the trials tended to stick to a lower salt diet compared to those who had been in the control group.

The researchers garnered information from 2415 (77.3%) participants, 200 of whom had reported some sort of cardiovascular problem and it was seen that the reduction in the risk of developing cardiovascular problems as a result of the sodium reduction intervention was substantial.

The results showed that the pre-hypertensive individuals were 25% less likely to develop cardiovascular problems over the course of the 10-15 years post-trial and there was also a 20% lower mortality rate.

This risk reduction was clearly seen in each trial.

Dr. Cook's team say salt may affect artery and heart health in ways that go beyond blood pressure; they say sodium may make blood vessels less able to expand and contract and may toughen heart cells.

They say their study provides unique evidence that lowering salt in the diet might prevent cardiovascular disease.

The National Heart, Lung and Blood Institute (NHLBI) which funded the study, says salt intake is clearly linked to high blood pressure and recommends that all Americans cut down on their sodium intake.

The NHLBI says in the U.S. today more than 65 million adults, one in three, have unacceptably high blood pressure, above levels of 140/90, and another 59 million have pre-hypertension - defined as blood pressure of 120/80 or above.

Experts say both the average U.S. and British diets contain far more than the 2,300 mg daily recommended salt intake.