A total of 27 patients (females n= 19 and males n= 8) with musculoskeletal symptoms had their plasma antioxidant ubiquinone plus vitamin E (a-tocopherol) and their essential fatty acids (EFAs) analyzed. They were antioxidant depleted but had normal w-6 and w-3 EFA levels as compared to healthy individuals. Nutritional therapy with either ubiquinone and vitamin E (study A, n= 16) alone or in combination with w-3 EFAs as a fish oil concentrate (study B, n= 11) increased plasma antioxidants after 3 months of nutritional therapy. Only the inclusion of w-3 EFAs (study B) had an effect on the plasma EFA and increased the w-3 series in absolute and relative terms. No gender differences were present either before or after the nutritional therapy. When antioxidant therapy was evaluated with respect to the patients' smoking habits, only the non-smokers appeared to gain w-3 EFA protection. The effect of antioxidants alone in the non-smokers and in combination with w-3 EFAs in all the patients seemed to depress the presence of one w-6 fatty acid in particular: arachidonic acid (AA). It seems reasonable to suggest that this could result in a reduced AA cascade