Serum carotenoids, α-tocopherol and mortality risk in a prospective study among Dutch elderly

Abstract

Background Although β-carotene has shown inverse associations with chronic diseases involving free radical damage in observational epidemiological studies less attention has been paid to five other major carotenoids also showing antioxidant activity in vitro. Methods We studied the associations between 7.2-year mortality and serum levels of six carotenoids, and α-tocopherol, measured in stored serum, sampled in 1991/1992 during a health survey among 638 independently living elderly subjects aged 65–85 years. Proportional hazards regression was used to estimate hazard ratios of all-cause mortality for the lowest tertiles of serum vitamins with the highest tertiles, adjusting for possible confounding effects. Results During a follow-up period of 7.2 years 171 elderly died. The adjusted hazard ratios for all-cause mortality for the lowest tertiles of vitamins compared with the highest tertiles were between 1.02 and 1.73. The strongest increase in mortality risk was seen for β-cryptoxanthin (1.52, 95% CI : 1.00, 2.32), lutein (1.56, 95% CI : 1.05, 2.31) and zeaxanthin (1.32, 95% CI : 0.89, 1.97) and their sum (oxygenated carotenoids: 1.73, 95% CI : 1.12, 2.67). Tests for trend were significant (P < 0.05) for all-cause mortality risk and serum levels of total carotenoids, oxygenated carotenoids and β-cryptoxanthin. Conclusions Our findings suggest that serum levels of individual carotenoids, particularly the oxygenated species are inversely associated with all-cause mortality and should be considered as candidates for further investigations.