Vitamin A, retinol, and carotenoids and the risk of gastric cancer: a prospective cohort study.
BACKGROUND
Vitamin A may influence gastric carcinogenesis through its essential role in controlling cell proliferation and differentiation. However, epidemiologic studies of vitamin A, retinol (preformed vitamin A), and provitamin A carotenoids in relation to the risk of gastric cancer have documented inconsistent results.


OBJECTIVE
The objective of the study was to examine the associations between intakes of vitamin A, retinol, and specific carotenoids and the risk of gastric cancer in a prospective population-based cohort study of Swedish adults.


METHODS
The study cohort consisted of 82 002 Swedish adults aged 45-83 y who had completed a food-frequency questionnaire in 1997. The participants were followed through June 2005.


RESULTS
During a mean 7.2-y follow-up, 139 incident cases of gastric cancer were diagnosed. High intakes of vitamin A and retinol from foods only (dietary intake) and from foods and supplements combined (total intake) and of dietary alpha-carotene and beta-carotene were associated with a lower risk of gastric cancer. The multivariate relative risks for the highest versus lowest quartiles of intake were 0.53 (95% CI: 0.32, 0.89; P for trend = 0.02) for total vitamin A, 0.56 (95% CI: 0.33, 0.95; P for trend = 0.05) for total retinol, 0.50 (95% CI: 0.30, 0.83; P for trend = 0.03) for alpha-carotene, and 0.55 (95% CI: 0.32, 0.94; P for trend = 0.07) for beta-carotene. No significant associations were found for beta-cryptoxanthin, lutein and zeaxanthin, or lycopene intake.


CONCLUSIONS
High intakes of vitamin A, retinol, and provitamin A carotenoids may reduce the risk of gastric cancer.
Larsson
Susanna C
SC
Division of Nutritional Epidemiology, The National Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden. susanna.larsson@ki.se
Bergkvist
Leif
L
Näslund
Ingmar
I
Rutegård
Jörgen
J
Wolk
Alicja
A
D000368:Aged; D000369:Aged, 80 and over; D002338:Carotenoids / Q000008:administration & dosage / Q000494:pharmacology*; D015331:Cohort Studies; D004198:Disease Susceptibility; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D013274:Stomach Neoplasms / Q000517:prevention & control*; D011795:Surveys and Questionnaires; D013548:Sweden; D014801:Vitamin A / Q000008:administration & dosage / Q000494:pharmacology*
D014801:Vitamin A; D002338:Carotenoids