Effects of vitamin E from supplements and diet on colonic α- and γ-tocopherol concentrations in persons at increased colon cancer risk.
Nutr Cancer
; 67(1): 73-81, 2015.
Article
em En
| MEDLINE
| ID: mdl-25372556
ABSTRACT
The available evidence indicates that γ-tocopherol has more potential for colon cancer prevention than α-tocopherol, but little is known about the effects of foods and supplements on tocopherol levels in human colon. This study randomized 120 subjects at increased colon cancer risk to either a Mediterranean or a Healthy Eating diet for 6 mo. Supplement use was reported by 39% of the subjects, and vitamin E intake from supplements was twofold higher than that from foods. Serum α-tocopherol at baseline was positively predicted by dietary intakes of synthetic vitamin E in foods and supplements but not by natural α-tocopherol from foods. For serum γ-tocopherol, dietary γ-tocopherol was not a predictor, but dietary α-tocopherol was a negative predictor. Unlike with serum, the data supported a role for metabolic factors, and not a direct effect of diet, in governing concentrations of both α- and γ-tocopherol in colon. The Mediterranean intervention increased intakes of natural α-tocopherol, which is high in nuts, and decreased intakes of γ-tocopherol, which is low in olive oil. These dietary changes had no significant effects on colon tocopherols. The impact of diet on colon tocopherols therefore appears to be limited.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Vitamina E
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Colo
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Neoplasias do Colo
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Alfa-Tocoferol
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Gama-Tocoferol
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Mucosa Intestinal
Tipo de estudo:
Clinical_trials
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Etiology_studies
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Prognostic_studies
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Risk_factors_studies
Limite:
Female
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Humans
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Male
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Middle aged
País como assunto:
America do norte
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article