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Background: The protective effects of antioxidant vitamins on hearing loss are well established in animal studies but in few human studies. Recent animal studies suggest that magnesium intake along with antioxidants may act in synergy to prevent hearing loss. Objective: We examined associations between intake of antioxidant vitamins (daily b-carotene and vitamins C and E) and magnesium and hearing thresholds and explored their joint effects in US adults. Design: We analyzed cross-sectional data from 2592 participants aged 20-69 y from NHANES 2001-2004. Hearing thresholds as pure tone averages (PTAs) at speech (0.5, 1, 2, and 4 kHz) and high frequencies (3, 4, and 6 kHz) were computed. Results: When examined individually, modeled as quartiles, and after adjustment for potential confounders, higher intakes of b-carotene, vitamin C, and magnesium were associated with lower (better) PTAs at both speech and high frequencies. High intakes of β-carotene or vitamin C combined with high magnesium compared with low intakes of both nutrients were significantly associated with lower (better) PTAs at high frequencies (214.82%; 95% CI: 220.50% to 28.74% for b-carotene + magnesium and 210.72%; 95% CI: 216.57% to 24.45% for vitamin C + magnesium). The estimated joint effects were borderline significantly larger than the sums of the individual effects [high β-carotene/low magnesium (24.98%) and low β-carotene/high magnesium (20.80%), P-interaction = 0.08; high vitamin C/low magnesium (21.33%) and low vitamin C/high magnesium (2.13%), P-interaction = 0.09]. Conclusion: Dietary intakes of antioxidants and magnesium are associated with lower risks of hearing loss [ABSTRACT FROM AUTHOR]

The authors examined long-term antioxidant intake in relation to cognitive decline among older women. Beginning in 1980, Nurses’ Health Study (NHS) participants completed dietary assessments every 4 years; in 1995–2001, 16,010 participants aged ≥70 years completed initial cognitive assessments, which were repeated 3 times at 2-year intervals. Long-term antioxidant intake was averaged from 1980 through the time of initial cognitive interviews. Multivariable-adjusted linear regression was used to estimate mean differences in rates of cognitive decline across categories of vitamin E, vitamin C, and carotenoid intake; statistical tests were 2-sided. No associations were evident for vitamin E or total carotenoid intake and cognitive decline (e.g., after multivariable adjustment, P-trend = 0.44 and P-trend = 0.51, respectively, for a global composite score averaging all 6 cognitive tests), although higher lycopene intake and lower vitamin C intake were related to slower cognitive decline. In alternative analyses of overall cognitive status at older ages (averaging all 4 cognitive assessments), results for vitamins E and C were generally null, but higher carotenoid intake was related to better cognition. Overall, long-term vitamin E and C intakes were not consistently related to cognition, although greater consumption of carotenoids may have cognitive benefits in older adults. [ABSTRACT FROM PUBLISHER]

ObjectiveTo investigate the association of antioxidant intakes from diet and supplements with elevated blood C-reactive protein (CRP) and homocysteine (Hcy) concentrations.DesignA cross-sectional study. The main exposures were vitamins C and E, carotene, flavonoid and Se intakes from diet and supplements. Elevated blood CRP and Hcy concentrations were the outcome measures.SettingThe US population and its subgroups.SubjectsWe included 8335 US adults aged ≥19 years from the National Health and Nutrition Examination Survey 1999–2002.ResultsIn this US population, the mean serum CRP concentration was 4·14 (95 % CI 3·91, 4·37) mg/l. Intakes of vitamins C and E and carotene were inversely associated with the probability of having serum CRP concentrations >3 mg/l in multivariate logistic regression models. Flavonoid and Se intakes were not associated with the odds of elevated serum CRP concentrations. The mean plasma Hcy concentration was 8·61 (95 % CI 8·48, 8·74) μmol/l. Intakes of vitamins C, E, carotenes and Se were inversely associated with the odds of plasma Hcy concentrations >13 μmol/l after adjusting for covariates. Flavonoid intake was not associated with the chance of elevated plasma Hcy concentrations.ConclusionsThese results suggest that high antioxidant intake is associated with lower blood concentrations of CRP and Hcy. These inverse associations may be among the potential mechanisms for the beneficial effect of antioxidant intake on CVD risk mediators in observational studies. [ABSTRACT FROM PUBLISHER]

Given the importance of dietary antioxidants in reducing the risks of chronic diseases, the present study aimed to estimate the intake of total antioxidant capacity (TAC) from diet and dietary supplements of US adults. We utilised the US Department of Agriculture flavonoid and proanthocyanidin databases, dietary supplement data and food consumption data of 4391 US adults aged 19+ years in the National Health and Nutrition Examination Survey 2001–2. In order to convert the intake data of individual antioxidant compounds to TAC values, the vitamin C equivalent (VCE) of forty-three antioxidant nutrients measured previously was also applied. Daily TAC averaged 503·3 mg VCE/d (approximately 75 % from diet and 25 % from supplements). The energy-adjusted daily TAC level from diet and supplements was higher in women (except for carotenoids), older adults, Caucasian (except for carotenoids), non-alcohol consumers (for vitamin E and proanthocyanidins), subjects with higher income (except for carotenoids) and higher exercise levels than their counterparts (P < 0·05). TAC was positively associated with daily consumption of fruits and fruit juices, vegetables and vegetable products, beverages, wines and teas (P < 0·001). Teas, dietary supplements, and fruits and fruit juices were the major sources of dietary TAC of the US population (28, 25 and 17 %, respectively), while the contribution of vegetables and vegetable products to TAC was minimal ( < 2 %). The present study indicates that antioxidant intake from various diet and supplements contributes to TAC status. TAC levels are different in sociodemographic subgroups of the US population. The relationship between TAC intake and risks of chronic disease warrants further investigation. [ABSTRACT FROM PUBLISHER]

The article reports on respiratory health and low dietary nutrient intakes in adolescents. It is posed that epidemiologic studies have outlined that a diet rich in antioxidants, fruits, and n-3 fatty acids may contribute to optimal respiratory health. In this study, the association of dietary factors which include fruits, vegetables, vitamins C and E, and beta-carotene with respiratory health in 2,112 students in 13 communities in the United States and Canada were examined.