Reducing Sodium Decreases Long-Term Risk for Cardiovascular Disease
A clinical trial from the National Heart, Lung and Blood Institute shows that people with pre-hypertension who reduced their sodium intake by 25 to 35 percent had a 25 percent lower risk of total cardiovascular disease over the 10 to 15 years during which they cut back on salt.
Schmalfeldt: You've heard all about the many benefits of reducing your sodium intake - preventing high blood pressure leading the list. Now, if you needed yet another reason to cut back on salt, new data from a clinical trial from the National Heart, Lung and Blood Institute shows that people with pre-hypertension who reduced their sodium intake by 25 to 35 percent had a 25 percent lower risk of total cardiovascular disease over the 10 to 15 years during which they cut back on salt. Dr. Jeffrey Cutler, NHLBI Project Officer of the Trials of Hypertension Prevention Program — also known as TOHP — said it's reasonable to assume that the reduction in heart disease risk goes hand-in-hand with the reduced risk of high blood pressure that results when a person reduces his or her sodium intake.
Cutler: That's the logical interpretation. There are data from both animal studies and human population studies that reducing sodium might have some benefits seperable from its effect on blood pressure, but most likely the major chain of causation is through its effect on blood pressure.
Schmalfeldt: Two of these TOHP trials were conducted in 10 clinical sites — one from 1987 to 1990, the other from 1990 to 1995, with follow up for 10 to 15 years after each trial. This new follow-up data shows that the groups who reduced their sodium intake also had lower mortality from cardiovascular disease. Dr. Cutler said the news may even be better than it seems at first blush.
Cutler: The levels attained in these randomized trials conducted in the late 1980s and early 1990s were substantial, but they were not even at the level of what the guidelines recommended at that time. In fact, for much of the population, the guidelines are now recommending lower levels in part because of another study that NHLBI sponsored —the DASH Sodium Study— which showed that for a given amount of sodium reduction, the blood pressure reduction is greater in the lower range levels than at the higher range levels. So, we're operating in THOP, for the most part, in the range above the area where you get the maximum benefit. So it is very likely that this study underestimates the potential public health benefit.
Schmalfeldt: The new data has been published online by the British Medical Journal. From the National Institutes of Health, I'm Bill Schmalfeldt in Bethesda, Maryland.
About This Audio Report
Reporter: Bill Schmalfeldt
Sound Bite: Dr. Jeffrey Cutler
Topic: Heart Disease