Abstract and Introduction
To assess the relationship between antioxidant vitamin intake and all-cause mortality in older adults, we examined these associations using data from the Leisure World Cohort Study, a prospective study of residents of the Leisure World retirement community in Laguna Hills, California. In the early 1980s, participants (who were aged 44–101 years) completed a postal survey, which included details on use of vitamin supplements and dietary intake of foods containing vitamins A and C. Age-adjusted and multivariate-adjusted (for factors related to mortality in this cohort—smoking, alcohol intake, caffeine consumption, exercise, body mass index, and histories of hypertension, angina, heart attack, stroke, diabetes, rheumatoid arthritis, and cancer) hazard ratios for death were calculated using Cox regression for 8,640 women and 4,983 men (median age at entry, 74 years). During follow-up (1981–2013), 13,104 participants died (median age at death, 88 years). Neither dietary nor supplemental intake of vitamin A or vitamin C nor supplemental intake of vitamin E was significantly associated with mortality after multivariate adjustment. A compendium that summarizes previous findings of cohort studies evaluating vitamin intake and mortality is provided. Attenuation in the observed associations between mortality and antioxidant vitamin use after adjustment for confounders in our study and in previous studies suggests that such consumption identifies persons with other mortality-associated lifestyle and health risk factors.
Oxidative stress has been suggested to increase the incidence of chronic disease and mortality. The oxidative-modification hypothesis regarding atherosclerosis suggests that antioxidants may inhibit the oxidation of low-density lipoprotein cholesterol, hindering its ability to clog the coronary arteries and preventing cardiovascular disease.[1,2] Increasing evidence suggests that oxidative stress is also involved in cerebral aging, cognitive impairment, and dementia.[3,4] In addition, antioxidants may prevent cancer by inhibiting the formation of carcinogenic nitrosamines, protecting DNA from oxidative damage, and enhancing immune function. Thus, dietary and supplemental intake of antioxidant vitamins may help reduce the incidence of cardiovascular disease, cancer, and dementia and thereby reduce mortality. However, few studies have examined the possible protective association for dietary and supplemental intake of vitamins A, C, and E together in the same population group.
In 1981, we undertook a prospective cohort study of nearly 14,000 elderly men and women with the aim of studying factors, especially modifiable lifestyle practices, associated with longevity and successful aging. We report here the associations between antioxidant vitamin intake (dietary and supplemental) and all-cause mortality after 32 years of follow-up.
Am J Epidemiol. 2015;181(2):120-126. © 2015 Oxford University Press