ANOTHER SALVO has been fired in the ongoing debate over the efficacy of restricting intake of high-cholesterol foods (JAMA1986;256:2775-2780). "There is almost a fanaticism about cholesterol levels... but for two thirds of people, lowering dietary cholesterol will not affect [their plasma] cholesterol levels," says Tucson nutritionist Donald J. McNamara, PhD. This is so, he says, because most people have built-in feedback mechanisms to maintain their baseline plasma cholesterol levels, irrespective of dietary modification. Dallas cholesterol expert Scott M. Grundy, MD, has some reservations about interpreting McNamara's results as suggesting that most people should not worry about dietary cholesterol, but he thinks the work is "provocative, important, and very carefully done." McNamara, professor of nutrition and food science at the University of Arizona, spoke about his latest research at an American Diabetes Association Science Writers Seminar in Palm Desert, Calif. He and coworkers have been attempting to unravel the nature