He and his colleagues found that the red blood cells of smokers who had been given a placebo were three times more susceptible to the damage caused by free radicals than were those of nonsmokers. But the cells of smokers who had taken vitamin E were as resistant to free-radical damage as were those of nonsmokers.

Also presented Tuesday at the conference on vitamin E: a preliminary study by Dr. Stanley Fahn of Columbia Presbyterian Medical Center in New York suggesting that daily vitamin E doses may delay the progression of Parkinson's disease.