Dr. Louis Tobian, professor of medicine at the University of Minnesota School of Medicine, gave the first in a series of public lectures by distinguished nutritionists on January 9. His subject was "Dietary Strategies for blood Pressure Control."

The prehistoric ancestors from whom we inherited our genetic makeup were hunter-gatherers. Their diets came from one-third meat and two-third vegetables. Such a diet was made up of natural foods very high in potassium and low in sodium. The diet was low in fat, and the fats it contained were primarily vegetable or fish oils.

The result was no high blood pressure, no diabetes and no atherosclerosis to cause heart attacks or strokes. Yet when certain Indians who lead the same lifestyle today move to the city they become susceptible to these diseases. Tobian believe that many modern diseases are nutritionally related.

He presented research indicating that a diet high in potassium guards against some damage to the circulatory system associated with high blood pressure. The hunter-gatherer man averages 10 grams of potassium a day. Middle class whites in the U.S. take in about 2.5 grams a day, only one-fourth as much. Research comparing 4:0 proportions of potassium on stroke-prone rats showed that animals receiving the higher percentage of potassium had an 86% lower death rate from stroke.

The higher level of potassium also appears to guard against kidney damage associated with high blood pressure. These striking studies suggest there is a price we pay for not eating as much potassium as the prehistoric man. Tobian suggests we try to average 5 grams of potassium a day and suggests these high-potassium foods: bananas (440 mgs each), baked potato (782 mg.) and most leafy vegetables (one cup cooked spinach, 583 mg.; one 6" head iceberg lettuce, 943 mg.). Mushrooms, skimmed milk, bran, orange or grapefruit juice, peaches, apricots and blackstrap molasses are also rich in potassium.