Spring 2001 Buehler-Martin Distinguished Lecture Series - April 16, 17
and 19, 2001
University of Minnesota
School of Statistics
College of Liberal Arts
Salt and Blood Pressure: Conventional Wisdom Reconsidered
David Freedman
Professor of Statistics
University of California, Berkeley
Thursday, April 19, 2001
4:00 PM,
133
Physics
Minneapolis, East Bank Campus
Social at 3:30 PM,
300
Ford Hall
Abstract
The "salt hypothesis" is that higher levels of salt in the diet lead to higher
levels of blood pressure, with attendant risk of cardiovascular disease.
Intersalt was designed to test the hypothesis, with cross-sectional study of
salt levels and blood pressures in 52 populations. The study is often cited to
support the salt hypothesis, but the data are somewhat contradictory. Four of
the populations (Kenya, Papua, and two Indian tribes in Brazil) do indeed have
very low levels of salt and blood pressure. Across the other 48 populations,
however, blood pressures go down as salt levels go up contradicting the salt
hypothesis. Experimental evidence suggests that the effect of a large reduction
in salt intake on blood pressure is modest, and health consequences remain to be
determined.