Zinc supplementation and plasma lipid peroxides in an elderly population

Objective: To determine the effect of vitamin A, zinc or both on plasma lipid peroxides in a healthy elderly population. Design: Double-blind randomized controlled trial supplementation of vitamin A and zinc. Setting: Public home for elderly people, in Pome, Italy. Subjects: A total of 178 residents of a Public home for elderly people were evaluated regarding health and nutritional status. 136 gave a written consensus to participate in the trial and were randomized in four groups of treatment. 118 elderly completed the trial. Interventions: Three months supplementation of the following treatments: (1) vitamin A (800 mu g retinol palmitate); (2) zinc (25 mg zinc as sulphate); (3) vitamin A and zinc (800 mu g retinol palmitate and 25 mg zinc as sulphate); (4) placebo (starch containing capsules). Main outcome measures: Plasma lipid peroxides (TBA-RS) were measured before and after supplementation. Results: Zinc supplementation was associated with a decrease in plasma lipid peroxides (beta = -0.19; 95% confidence levels: -0.37, -0.002; p-value = 0.05) after adjusting for sex, smoking habits, baseline plasma lipid peroxides and vitamin A plasma levels. Conclusions: Zinc supplementation decreased plasma lipid peroxides while vitamin A had no effect in this elderly population. Adequate zinc intake or supplementation could play an important role in the prevention and/or modulation of diseases in the elderly people.