Excess salt may stiffen heart vessels
Coronary risk factor linked to higher dietary sodium, independent of blood pressure
By Janet Raloff
Eating foods laced with too much salt may be as risky as smoking cigarettes, at least in terms of a risk factor for heart attacks called coronary flow reserve, a new study of middle-aged American men finds.
Coronary flow reserve, or CFR, offers a gauge of how well tiny blood vessels in the heart dilate or contract in response to hormonal commands. The lower the CFR, the stiffer the vessels — and the less responsive they become to the heart’s constantly changing workloads.
The new study examined CFR and salt intake among 143 pairs of male twins in their 50s or older. CFR declined by about 10 percent for each additional 1,000 milligrams of sodium that a man consumed per day compared with his brother.
“That’s huge,” says Viola Vaccarino of Emory University in Atlanta and coauthor of the study, which appears in the March American Journal of Clinical Nutrition. The difference in CFR for men with the highest sodium intake versus those with the lowest, she notes, was equivalent to changes other studies had linked to smoking.