OBJECTIVES Antioxidant nutrients like carotenoids, tocopherols and vitamin C have been suggested to protect against allergic rhinitis and allergic sensitisation but scientific evidence is scarce. The aims of the study were to measure the plasma concentration of six carotenoids, alpha- and gamma-tocopherol and vitamin C as biomarkers of the intake, absorption and subsequent metabolism of these n...

Antioxidant micronutrients may have chemopreventive effects. The authors examined the associations between prediagnostic blood levels of micronutrients and prostate cancer risk in two nested case-control studies of 9,804 and 10,456 male residents of Washington County, Maryland, who donated blood in 1974 (CLUE I) and 1989 (CLUE II), respectively. Until 1996, 182 men for whom adequate serum remai...

A tissue-specific distribution of the various vitamin E forms, tocotrienols and tocopherols, has been found, suggesting that these forms have unique roles in cellular functions. A sensitive procedure is described for the simultaneous determination of individual tocopherols, tocotrienols, ubiquinols, and ubiquinones using gradient high pressure liquid chromatography (HPLC) and electrochemical de...

Twelve pumpkin cultivars (Cucurbita maxima D.), cultivated in Iowa, were studied for their seed oil content, fatty acid composition, and tocopherol content. Oil content ranged from 10.9 to 30.9%. Total unsaturated fatty acid content ranged from 73.1 to 80.5%. The predominant fatty acids present were linoleic, oleic, palmitic, and stearic. Significant differences were observed among the cultivar...

The aim of this study was to investigate the effect of different types of tomato processing on contents of lycopene, beta-carotene, and alpha-tocopherol. Samples of tomato sauce, tomato soup, baked tomato slices, and tomato juice were taken at different times of heating, respectively, after each step of production. HPLC was used to analyze contents of carotenoids and vitamin E. Due to the loss ...

BACKGROUND Tocopherols may protect against prostate cancer and cardiovascular disease (CVD). METHODS We assessed the effect of walnuts, which are rich in tocopherols, on markers of prostate and vascular health in men at risk for prostate cancer. We conducted an 8-week walnut supplement study to examine effects of walnuts on serum tocopherols and prostate specific antigen (PSA). Subjects (n = ...

Despite a large number of previous studies, the mechanism of free radical interaction between vitamin E (VE) (alpha-, beta-, gamma- and delta-tocopherol) and ascorbate or flavonoids as coantioxidants remains unclear. VE, particularly alpha-tocopherol, shows less antioxidant activity against peroxyl radicals, suggesting that VE possesses functions that are independent of its antioxidant/radical-...

A method is described for the simultaneous measurement of probucol, retinol, tocopherols, lycopene, and carotenes by reverse phase high performance liquid chromatography. A high sensitivity was achieved by use of a microbore column and by monitoring the effluent at the optimum wavelengths of each substance with a diode array detector. The detection limits were lycopene 0.5 ng; alpha-carotene, b...

Soybean seeds which had aged in long-term storage ("natural aging") or by exposure to high temperature and humidity ("accelerated aging") were analyzed for their tocopherol and organic free radical contents. Tocopherol levels remained unchanged during both types of aging. Three principal tocopherol homologues (alpha, gamma, delta) were present in fairly constant proportions throughout. Organic ...

Numerous properties suggest that antioxidants and carotenoids may be valuable chemopreventive agents. A population-based case-control study of 952 rectal cancer cases and 1,205 controls from Northern California and Utah was conducted between September 1997 and February 2002. Detailed diet history, medical history, and lifestyle factors interviews were conducted. Dietary antioxidants were not as...