| Carotenoids have been linked with individual cardiovascular, metabolic, and inflammatory markers of disease. However, little is known about the effect of carotenoids on allostatic load, an indicator of the negative cumulative effect of lifetime environmental stress on the biological stress adaptation capacity. The purpose of this study was to examine the association of serum concentrations of carotenoids with allostatic load among middle-aged (45-64 years, N=3,347) men and women who participated in the Third National Health and Nutrition Examination Survey (1988-1994). The outcome was sex-specific allostatic load score, based on 9 risk-rated indicators (systolic and diastolic blood pressure, pulse rate, total and high density cholesterol, glycosylated hemoglobin, sex-specific waist-to-hip ratio, albumin and C-reactive protein). Allostatic load was categorized as high when two or more indicators were in the high risk category. In logistic regression analysis, beta-carotene and total carotenoids were inversely associated with high allostatic load, in a dose-dependent manner, after adjusting for education, race-ethnicity, serum cotinine, alcohol consumption, vitamin/mineral supplementation, physical activity, and other carotenoids (alpha-carotene, beta-cryptoxanthin, lycopene, lutein/zeaxanthin). Males in the lowest beta-carotene and total carotenoid quartiles were 2.06 [95% confidence interval, CI 1.29-3.29] and 1.58[95% CI 1.11-2.24] times as likely to have high allostatic load, compared to their male peers in the highest quartile. The respective odds ratios for females were 2.73 [95% CI 1.71-4.35] and 2.11[95% CI 1.53-2.92]. Low total carotenoid status is related to the broad physiologic dysregulation from lifetime stress exposure among middle aged adults. More research is needed to further explore the role of carotenoids in the physiological adaptation to environmental stress. |