WMA Statement on Reducing Dietary Sodium Intake
Adopted by the 59th WMA General Assembly, Seoul, Korea, October 2008
Cardiovascular diseases (CVD) remain a leading cause of mortality throughout the world. Risk factors include high blood cholesterol, hypertension, cigarette smoking, physical inactivity, obesity, and diabetes. These risk factors are largely preventable and modifiable.
Globally, about 25% of all deaths from cardiovascular diseases are due to hypertension. This figure may underestimate the true impact of 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 cardiovascular diseases 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, population-wide 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 a 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 optimal body weight, and moderation in alcohol intake are also recommended lifestyle approaches to preventing and managing hypertension and reducing its impact on cardiovascular disease.
The World Health Organization recommends that average daily sodium consumption in adults should be less than 2000 mg (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 <1500 mg (3.8 g salt) per day, supports the concept of such a threshold, above which the risk for harmful cardiovascular disease consequences begins to increase.
The world's population consumes 2300-4600 mg of sodium (5.8 - 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 programs. The largest impact on 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.
National Medical Associations should:
- In cooperation with national and international health organizations, work to educate consumers about the effects of sodium intake on hypertension and cardiovascular disease, the benefits of long-term reductions in sodium intake, and about the dietary sources of salt/sodium and how these can be reduced.
- Call for a stepwise 50% reduction in the sodium content of processed foods, "fast" food products, and restaurant meals over the next decade.
- Urge physicians to counsel patients about the major sources of sodium in their diets and how to reduce sodium intake, including reducing the amount of salt used in cooking at home.
- In cooperation with the food industry and government regulators, discuss ways to improve labeling of food products and develop label markings and warnings for foods high in sodium.
- Encourage government authorities to create national laws and regulations that enforce the reduction of sodium in processed foods to acceptable levels. Establish a deadline for industries to comply with new laws and regulations.
- Stimulate debate on the issue at conferences, symposia, and teleconferences in an effort to promote awareness among the medical profession regarding sodium in food and its consequences. Doctors who are well-informed will transmit the information to their patients and may be able to prescribe fewer antihypertensive medications.