Biochemical antioxidant levels respond to supplementation with an enriched drink in frail elderly people

Objective: To investigate whether a drink enriched with essential vitamins and minerals can improve biochemical status of enzymatic and non-enzymatic antioxidants in frail elderly people. Methods: A six-month randomized, double blind, placebo controlled intervention study. Frail elderly people 65 years of age or older, with a body mass index (BMI) below 25 kg/m(2) and residing in a home for the elderly or in sheltered housing. Enriched (with essential vitamins and minerals in 30% to 150% of RDA and higher levels of antioxidants) drink (n = 28) or placebo (n = 27) to be taken twice a day in addition to the normal food consumed. Plasma levels of vitamin C, vitamin E, antioxidant capacity (TEAC), cysteine, uric acid and whole blood levels of total thiol and glutathione peroxidase (GSH-Px), dietary intake. Results: Changes in vitamin E (16 +/- 2 vs. 2 +/- 1 mmol/L), vitamin C (37 +/- 5 vs. 1 +/- 5 mmol/L), TEAC (38 +/- 15 vs. -10 +/- 11 mmol/L Trolox eq) and cysteine (17 +/- 10 vs. 0.4 +/- 6 mmol/L) were significantly different between groups (p < 0.05). There was a trend towards significant changes in erythrocyte glutathione peroxidase (-0.2 +/- 3 vs. -10 +/- 7 U/mg Hb, p = 0.097). Baseline dietary intake of antioxidant vitamins was below 2/3 RDA for a substantial proportion (43% to 76%) of subjects. Conclusions: Supplementation with an enriched drink can raise plasma levels of enzymatic and nonenzymatic antioxidants in frail elderly people.