title: Low-serum carotenoid concentrations and carotenoid interactions predict mortality in US adults: the Third National Health and Nutrition Examination Survey.
abstract: Evidence regarding the health benefits of carotenoids is controversial. Effects of serum carotenoids and their interactions on mortality have not been examined in a representative sample of US adults. The objective was to examine whether serum carotenoid concentrations predict mortality among US adults. The study consisted of adults aged ≥20 years enrolled in the Third National Health and Nutrition Examination Survey, 1988 to 1994, with measured serum carotenoids and mortality follow-up through 2006 (N = 13,293). Outcomes were all-cause, cardiovascular disease, and cancer mortality. In adjusted Cox proportional hazards models, participants in the lowest total carotenoid quartile (<1.01 μmol/L) had significantly higher all-cause mortality (mortality rate ratio, 1.38; 95% confidence interval, 1.15-1.65; P = .005) than those in the highest total carotenoid quartile (>1.75 μmol/L). For α-carotene, the highest quartile (>0.11 μmol/L) had the lowest all-cause mortality rates (P < .001). For lycopene, the middle 2 quartiles (0.29-0.58 μmol/L) had the lowest all-cause mortality rates (P = .047). Analyses with continuous carotenoids confirmed associations of serum total carotenoids, α-carotene, and lycopene with all-cause mortality (P < .001). In a random survival forest analysis, very low lycopene was the carotenoid most strongly predictive of all-cause mortality, followed by very low total carotenoids. α-Carotene/β-cryptoxanthin, α-carotene/lutein+zeaxanthin and lycopene/lutein+zeaxanthin interactions were significantly related to all-cause mortality (P < .05). Low α-carotene was the only carotenoid associated with cardiovascular disease mortality (P = .002). No carotenoids were significantly associated with cancer mortality. Very low serum total carotenoid, α-carotene, and lycopene concentrations may be risk factors for mortality, but carotenoids show interaction effects on mortality. Interventions of balanced carotenoid combinations are needed for confirmation.
authors.affiliation: Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, MD 21201, USA. mshardel@epi.umaryland.edu
authors.forename: Michelle D
authors.initials: MD
authors.lastname: Shardell
authors.forename: Dawn E
authors.initials: DE
authors.lastname: Alley
authors.forename: Gregory E
authors.initials: GE
authors.lastname: Hicks
authors.forename: Samer S
authors.initials: SS
authors.lastname: El-Kamary
authors.forename: Ram R
authors.initials: RR
authors.lastname: Miller
authors.forename: Richard D
authors.initials: RD
authors.lastname: Semba
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferrucci
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000975:Antioxidants / Q000494:pharmacology; D015992:Body Mass Index; D002338:Carotenoids / Q000097:blood* / Q000172:deficiency*; D065366:Cryptoxanthins; D005260:Female; D005638:Fruit; D006801:Humans; D016015:Logistic Models; D014975:Lutein / Q000097:blood; D000077276:Lycopene; D008297:Male; D009026:Mortality; D009749:Nutrition Surveys; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D014675:Vegetables; D024341:Xanthophylls / Q000097:blood; D065146:Zeaxanthins
chemical_list: D000975:Antioxidants; D065366:Cryptoxanthins; D024341:Xanthophylls; D065146:Zeaxanthins; D002338:Carotenoids; C041635:alpha-carotene; D000077276:Lycopene; D014975:Lutein