Reducing Dietary Sodium(salt) Intake

[Adapted by the World Medical Association(WMA) General Assembly, Seoul, South Korea, October 2008]

Cardiovascular diseases(CVD) remain a leading cause of mortality throughout the world. Risk factors include high blood cholesterol, hypertension, smoking, physical inactivity, obesity and diabetes. These risk factors are largely preventable and modifiable.

Globally, about 25% of all deaths from CVD are due to hypertension. This figure may underestimate the true impact of the elevated blood pressure since the blood pressure cardiovascular risk continuum begins at 115/75 mm Hg. There is overwhelming evidence that excessive sodium intake is a risk factor for the development or worsening of hypertension and it may also be an independent risk factor for CVD as well as all-cause mortality.

Substantial overall benefits can accrue from even small reductions in the population's blood pressure. Depending upon an individual's salt sensitivity, sodium may cause great damage to both normotensive and hypertensive populations. Therefore, populationwide efforts to reduce dietary sodium intake are a cost-effective way to reduce overall hypertension levels and subsequent cardiovascular disease.

In acculturated populations, the level of blood pressure, the incremental rise in blood pressure with age and the prevalence of hypertension are related to salt intake. Observational studies and randomized controlled trials document a clear and consistent effect of salt consumption on increased blood pressure. Blood pressure is also affected by other foods and nutrients and reduced salt intake should be only one component of a comprehensive strategy to lower blood pressure. Increasing physical activity, consuming a diet high in fruits and vegetables and low in saturated and total fats, maintenance of ideal body weight and moderation of alcohol intake are also recommended life style approaches to preventing and managing hypertension and reducing its impact on cardiovascular disease.

WHO recommends that average daily sodium consumption in adults should be less than 2000mg (5 g salt). Epidemiologic evidence, including the marked reduction of either hypertension or of a progressive rise in blood pressure with advancing age in populations with an average sodium ingestion less than 1500mg (3.8 mg salt) per day, supports the concept of such a threshold, above which the risk of the harmful cardiovascular disease consequences begin to increase. The world's population consumes 2300-4600 mg of sodium (5.8 g-11.5 g salt) per day per 2000 calories. In developed countries, it is estimated that 75% to 80% of the daily intake of sodium comes from processed foods and foods that are prepared outside of the home (e.g. fast food or restaurant meals). Therefore, any meaningful strategy to reduce population salt intake must rely on food manufacturers and preparers to reduce the amount added during preparation as well as on nutritional education programmes. The largest impact in sodium in the food supply of developed countries may derive from the stepwise lowering of sodium in foods that are most commonly eaten and are large contributors to sodium intake. In less developed countries, reductions in sodium are more likely to be achieved by adding less salt during cooking inside the home.

[Courtesy:JIMA, VOL 107, NO. 3, MARCH 2009, PAGE 185]