The love affair between U.S. residents and salt is making us sick: high sodium intake increases blood pressure, and leads to higher rates of heart attack and strokes. Nonetheless, Americans continue to ingest far higher amounts of sodium than those recommended by physicians and national guidelines.
A balanced review of the relevant literature has been published in The New England Journal of Medicine. Theodore A. Kotchen, M.D., professor of medicine (endocrinology), and associate dean for clinical research at the Medical College of Wisconsin, is the lead author of the article.
Dr. Kotchen cites correlations between blood pressure and salt intake in a number of different studies; typically, the causation between lowering salt intake and decreased levels of blood pressure occur in individuals who have been diagnosed with hypertension. Although not as pronounced, there is also a link between salt intake and blood pressure in non-hypertensive individuals. Additionally, recent studies have demonstrated that a reduced salt intake is associated with decreased cardiovascular disease and decreased mortality.
In national studies in Finland and Great Britain, instituting a national salt-reduction program led to decreased sodium intake. In Finland, the resulting decrease in systolic and diastolic blood pressures corresponded to a 75 – 80 percent decrease in death due to stroke and coronary heart disease. Neverthelesss, not all investigators concur with population-based recommendations to lower salt intake, and the reasons for this position are reviewed.
“Salt is essential for life, but it has been difficult to distinguish salt need from salt preference,” said Dr. Kotchen. “Given the medical evidence, it seems that recommendations for reducing levels of salt consumption in the general population would be justifiable at this time.” However, in terms of safety, the lower limit of salt consumption has not beeen clearly identified. In certain patient groups, less rigorous targets for salt reduction may be appropriate.
Co-authors are Allen W. Cowley, Jr., Ph.D., James J. Smith and Catherine Welsh Smith Professor in Physiology, and Harry and Gertrude Hack Term Professor and chairman of Physiology, the Medical College of Wisconsin; Edward D. Frohlich, M.D., Alton Ocshner Distinguished Scientist at the Ochsner Clinic Foundation in New Orleans, La.
Medical College of Wisconsin