Antioxidants and reduced functional capacity in the elderly: findings from the Nun Study.

Abstract

This study investigated the relationship of plasma antioxidants to reduced functional capacity in the elderly. A hallmark of reduced functional capacity in the elderly is dependence in self-care (i.e., requiring assistance with bathing, walking, dressing, standing, toileting, and feeding). This relationship was assessed in a cross-sectional study of 88 Catholic sisters (nuns). These 77- to 98-year-old women lived in the same building, ate food prepared in the same kitchen, and had all nursing services provided by the same staff. In 1993, ability to perform self-care was assessed, and blood was drawn to determine plasma carotenoids (lycopene, beta carotene, alpha carotene, zeaxanthin and lutein combined, and beta cryptoxanthin) and alpha tocopherol. Dependence in self-care had a strong negative association with lycopene, but was not clearly related to other carotenoids or alpha tocopherol. Results from age-adjusted least squares regression indicated that a 30 micrograms/dl decrease in lycopene was associated with 2.4 additional dependencies in self-care (95% confidence interval = 1.5, 3.3; p < .001). Lycopene's relationship to dependence was modified by plasma LDL-cholesterol, the predominant carrier of lycopene in the blood. Women with low lycopene and low LDL-cholesterol had 3.6 dependencies (95% confidence interval = 3.1, 4.2; p < .001), compared to 1.0 dependency (95% confidence interval = 0.3, 1.8) in those with high lycopene and low LDL-cholesterol. This is the first study to report an association between lycopene and functional status. This finding needs to be replicated in other human and animal studies before the association is accepted as real.