RESUMEN
The effects on ex vivo LDL resistance to oxidation and biomarkers of in vivo oxidative stress in response to 3-month dietary vitamin E restriction to 25% of recommended intake and 2-month unrestricted dietary intake and supplementation with 800 IU/d were studied in 100 healthy, nonsmoking 20-75-year-old volunteers. Significant changes in vitamin E status were associated with decreases and increases, respectively, in LDL resistance to oxidation in the depletion and supplementation period and with decreases in lipid peroxidation and oxidative DNA modification in the supplementation period. Healthy aging was not associated with enhanced susceptibility to oxidation in the depletion period.
Asunto(s)
Envejecimiento , Biomarcadores/análisis , Estrés Oxidativo , Vitamina E/administración & dosificación , Adulto , Anciano , Antioxidantes/análisis , Carotenoides/sangre , ADN/química , Eritrocitos/química , Glutatión Peroxidasa/sangre , Humanos , Peroxidación de Lípido , Lipoproteínas LDL/sangre , Masculino , Persona de Mediana Edad , Vitamina E/sangreRESUMEN
The effects of age on vitamin E metabolism were studied in 97 healthy 20-75-year-old male nonsmoking Austrian volunteers of the VITAGE project. After a single oral intake of 30 mg d(6)-RRR-alpha- and d(2)-RRR-gamma-tocopheryl acetate, blood and 24-hour urine was collected. Deuterated tocopherols in plasma and deuterated urinary metabolites were analyzed by GC-MS. A first evaluation revealed a similar uptake of d(6)-alpha- and d(2)-gamma-tocopherol during the first 6 hours, and then d(2)-gamma-tocopherol started to decrease. Urinary d(2)-gamma- carboxyethyl hydroxychroman metabolites (CEHCs) exceeded those of d(6)-alpha-CEHCs by about 10 times. There was no effect of age. Thus, there might be no need for a higher vitamin E intake for healthy elderly nonsmoking men.
Asunto(s)
Envejecimiento , Estado Nutricional , Tocoferoles/metabolismo , Tocoferoles/farmacocinética , Vitamina E/metabolismo , Absorción , Adulto , Anciano , Austria , Cromanos/orina , Deuterio , Humanos , Masculino , Persona de Mediana Edad , Propionatos/orina , alfa-Tocoferol/sangre , alfa-Tocoferol/farmacocinética , alfa-Tocoferol/orina , gamma-Tocoferol/sangre , gamma-Tocoferol/farmacocinética , gamma-Tocoferol/orinaRESUMEN
A vitamin E depletion/supplementation study was conducted in 100 healthy 20-75-year-old volunteers. The responses of vitamin E status to 3-week dietary vitamin E restriction to approximately 25% of recommended intake and 2-month unrestricted dietary intake plus 800 IU/d of RRR-alpha-tocopherol were studied as a function of age. Plasma alpha-tocopherol concentrations were closely related to cholesterol concentrations, which increased with age (P < 0.001). Upon dietary restriction, plasma alpha-tocopherol concentrations decreased significantly (P < 0.001) but independently of age. Plasma alpha-tocopherol responses to supplementation increased significantly with age, but this effect disappeared after standardization for cholesterol. gamma-Tocopherol concentrations decreased to less than 30% of baseline.