This analysis, in part because of the large number of normotensive trials now published, does not support one of the goals of the Nutrition Labeling and Education Act (1990), that of lowering blood pressure in the normotensive population at large, and questions the wisdom of universal dietary sodium restriction without better evidence of the long-term benefits and safety of such an intervention.
"These results do not support a general recommendation to reduce sodium intake. Reduced sodium intake may be used as a supplementary treatment in hypertension. Further long-term studies of the effects of high reduction of sodium intake on blood pressure and metabolic variables may clarify the disagreements as to the role of reduced sodium intake, but ideally trials with hard end points such as morbidity and survival should end the controversy."
- Most people consume far more sodium than is necessary for survival.
- All studies of sodium consumption and reduction thereof are subject to severe methodological and logistical limitations.
- There are associations between sodium intake and blood pressure, and between blood pressure and clinical outcomes of interest.
- Reduction of sodium intake in patients with hypertension lowers blood pressure.
- None of this establishes a causal link between sodium intake or reduction thereof and clinical outcomes of interest other than hypertension in hypertensive persons.
(Added 6/7/2013: See this NYT article about the recent IOM report on reducing sodium intake.)