Intakes of vitamin C and carotenoids and risk of amyotrophic lateral sclerosis: pooled results from 5 cohort studies.
OBJECTIVE
Prior research has suggested the possible role of oxidative stress in the pathogenesis of amyotrophic lateral sclerosis (ALS). Prospective data examining dietary antioxidants such carotenoids and vitamin C are limited.


METHODS
Risk of ALS associated with carotenoid and vitamin C intake was investigated in 5 prospective cohorts: the National Institutes of Health-Association of American Retired Persons Diet and Health Study, the Cancer Prevention Study II Nutrition Cohort, the Multiethnic Cohort, the Health Professionals Follow-up Study (HPFS), and the Nurses Health Study (NHS). ALS deaths were documented using the National Death Index, and confirmed nonfatal ALS cases were included from HPFS and NHS. A total of 1,153 ALS deaths occurred among 1,100,910 participants (562,942 men; 537,968 women). Participants were categorized into cohort-specific quintiles of intake for dietary variables. We applied Cox proportional hazards regression to calculate cohort-specific risk ratios (RRs), and pooled results using random-effects methods.


RESULTS
A greater total major carotenoids intake was associated with a reduced risk of ALS (pooled, multivariate-adjusted RR for the highest to the lowest quintile = 0.75, 95% confidence interval [CI] = 0.61-0.91, p for trend = 0.004). Individually, higher dietary intakes of β-carotene and lutein were inversely associated with ALS risk. The pooled multivariate RRs comparing the highest to the lowest quintile for β-carotene and lutein were 0.85 (95% CI = 0.64-1.13, p for trend = 0.03) and 0.79 (95% CI = 0.64-0.96, p for trend = 0.01), respectively. Lycopene, β-cryptoxanthin, and vitamin C were not associated with reduced risk of ALS.


CONCLUSIONS
Consumption of foods high in carotenoids may help prevent or delay onset of ALS.
Department of Nutrition, Harvard School of Public Health, Boston, MA, USA. hpkcf@channing.harvard.edu
Kathryn C
KC
Fitzgerald
Éilis J
ÉJ
O'Reilly
Elinor
E
Fondell
Guido J
GJ
Falcone
Marjorie L
ML
McCullough
Yikyung
Y
Park
Laurence N
LN
Kolonel
Alberto
A
Ascherio
D000328:Adult; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000453:epidemiology* / Q000378:metabolism*; D000975:Antioxidants / Q000008:administration & dosage*; D001205:Ascorbic Acid / Q000008:administration & dosage*; D002338:Carotenoids / Q000008:administration & dosage*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000187:drug effects; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors
D000975:Antioxidants; D002338:Carotenoids; D001205:Ascorbic Acid