evidence: Dietary salt and blood pressure: A complex connection [...] One of the cardinal rules of heart-healthy eating is to avoid excess salt, which makes sense. The average American consumes the equivalent of about 1½ teaspoons of salt per day — about 50% more than the recommended amount. Getting too much sodium (a main component of salt) is closely linked to having high blood pressure (see "How sodium affects blood pressure"). [...] Unfortunately, there's no easy way to tell who is sensitive or insensitive to salt, and many people fall somewhere in the middle of those two extremes. But research is helping unravel the genetic basis of these differences, which may one day improve how doctors treat high blood pressure, according to endocrinologist Dr. Gordon Williams, professor of medicine at Harvard Medical School.