The discussion how dietary salt may affect blood pressure (BP) is still ongoing. The results from both epidemiological and interventional studies are inconsistent, which makes it difficult to draw firm conclusions.
The BP response to changes in dietary salt vary greatly dependent on for example BP status, renal function and age. How salt restriction affects BP, is difficult to predict. Salt sensitivity is based on the BP response to dietary salt, but is defined differently in the litterature. Thus, while older subjects and hypertensives may more often be perceived as salt sensitive, this contrast the findings in normotensive and young persons where salt restriction may not lead to BP reduction. However, there is evidence that reduced salt intake can prevent age-related increase in BP.
Great effort has been put into mapping of the genetic influence in hypertension. So far, the results have been disappointing. More research on this area is clearly necessary.
In the treatment of hypertension, salt restriction alone has little effect on BP, but may act synergistically with antihypertensive agents and lifestyle changes. On the other hand, there is ample evidence that salt restriction may prevent rise in BP. Thus, restriction of dietary salt is an important component of the multifactorial task aimed to prevent hypertension.
Reducing salt intake in processed food is necessary to achive lower salt intake in the population. The healt authorities must emphasize the importance of salt reduction as a preventive measure. This information must be directed both to the general population, and to the food industry. This appoach may be highly cost effective and important in preventing cardiovascular disease.