Heart study keeps pressure on salt reduction targets

New study adds further support for cutting sodium and boosting potassium intakes.

In the study, data was collected from 2,275 participants aged between 30 and 54 with a history of hypertension (1). The individuals were tested in two trials: TOHP I tested seven non-pharmacologic interventions for 18 months, including lifestyle interventions of weight loss, sodium reduction, and stress management, and supplements of calcium, magnesium, potassium, and fish oil. TOHP II tested the effect of weight loss and sodium reduction over a three-year period.

Over the course of the study, 193 cardiovascular disease (CVD) events were documented. While no differences were observed for levels of sodium excretion or potassium excretion independently, a significant trend was observed when the researchers considered the sodium to potassium excretion ratio.

The researchers found that the sodium to potassium excretion ratio was the strongest measure in predicting CVD. A higher sodium to potassium excretion ratio, indicative of higher sodium and lower potassium intakes, increased the risk of heart disease by 24%. The effect of urinary sodium or potassium excretion was enhanced when the other was included in the model, supporting the notion that the joint activity of these two electrolytes may have an important biologic role. These findings suggest that lowering dietary sodium intake, while increasing potassium consumption, at the population level might reduce the incidence of CVD.

Salt is of course a vital nutrient and is necessary for the body to function, but campaigners for salt reduction, like the Consensus Action on Salt and Health (CASH) consider the average daily salt consumption in the Western world, between 10 and 12g, far too high. Numerous scientists are convinced that high salt intake is responsible for increasing blood pressure (hypertension), a major risk factor for cardiovascular disease ? a condition that causes almost 50% of deaths in Europe.

1. Cook N. R. et al. Joint Effects of Sodium and Potassium Intake on Subsequent Cardiovascular Disease ? The Trials of Hypertension Prevention Follow-up Study. Archives of Internal Medicine, 2009; 169(1):32–40.