DASH for health

Today's Washington Post carries a reminder that the DASH Diet, high in fruits, vegetables and dairy products, provides vital potassium to blunt salt-sensitive hypertension. True, as far as it goes. The DASH Diet, released in 1997, promotes a food consumption pattern, although it does clearly make the most striking changes in overcoming mineral deficiencies. Those under-consumed minerals include not only potassium, but also calcium and magnesium. There is strong medical consensus that these essential nutrients are under-consumed in today's diet. The focus here is on blood pressure. When the DASH Diet was announced, the Salt Institute endorsed it strongly, since it focuses properly on enhanced mineral intake; it does not reduce dietary sodium/salt. For example, hypertensive subjects in the DASH Study population reduced their systolic blood pressure (SBP, the top number) by an impressive 11.4 mmHg. In a later study that also featured cutting salt by 60% (it was, after all, only a 30-day study), hypertensive patients on the DASH Diet with this drastically-reduced salt intake reduced their SBP by 11.5 mmHg. Salt restriction in 6 of the 8 subgroups reported (important because the sample represented particularly a salt-sensitive universe) no significant differences of blood pressure even when salt was reduced by more than half for those on the DASH Diet. We should all keep in mind that blood pressure is only one of several relevant health impacts. The key is to understand the net health outcome of any dietary change. As outlined on the Salt Institute website (http://www.saltinstitute.org/28.html), the limited studies on health outcomes of salt-reduced diets show no health benefit because other systems in the body are adversely affected by salt reduction (e.g. insulin resistance, plasma renin activity). So, eat those fruits and veggies -- and dairy products (dairy contributed more than half the blood pressure-lowering effect) -- but don't get too hung up on what our prehistoric ancestors ate. After all, they didn't live long enough to worry about blood pressure.