Rotterdam Study authors find no health benefit for cutting salt and "borderline" additional risk
A new Dutch study of 2,896 subjects studied for 5-6 years has concluded that there is no health benefit for healthy subjects to reduce dietary salt. The risk for subjects with cardiovascular disease and diabetes was not reported.
This, the 16th study of the health outcomes of reduced-salt diets, examined the incidence of heart attacks and strokes, cardiovascular mortality and all-cause mortality. Unfortunately, all the studies are observational (this is a case-cohort analysis); a controlled trial is required to address the question. The paper was published in the October issue of the European Journal of Epidemiology .
The research team headed by Diederick E. Grobbee examined a large, high-quality and much-admired database that contains data unavailable to some of the earlier studies. The authors reported:
Urinary sodium was not significantly associated with incident myocardial infarction, incident stroke, or overall mortality. For CVD mortality, however, a borderline significant inverse association was observed (RR = 0.77 (0.60-1.01) per 1-SD, model 3) but the relationship was attenuated after excluding subjects with a history of CVD or hypertension (RR = 0.83 (0.47-1.44) per 1-SD, model 3). In subjects initially free of CVD, the risk of all-cause mortality was also examined across quartiles of 24-h urinary sodium (median values: 45, 87, 125 and 190 mmol, respectively). RR in consecutive quartiles, using the lower quartile as the reference, were 0.80 (0.43-1.49), 0.66 (0.34-1.27) and 0.98 (0.54-1.78), respectively (model 3). In a subgroup analysis of CVD free subjects with a body mass index ≥25 kg/m2, the association of urinary sodium with CVD mortality or all-cause mortality was neither statistically significant (RR = 0.91 (0.44-1.89) and RR = 1.19 (0.86-1.66) per 1-SD, respectively; model 3).
