09 December 2013
A new US study reports that adequate intakes of antioxidant micronutrients such as beta-carotene, vitamin C and vitamin E may contribute to better hearing.
The observational study analyzed a potential link between daily intakes of antioxidant micronutrients and hearing ability (pure tone, speech and at high frequencies) of 2,592 participants aged 20–69 years (1). The study results showed that higher intakes of beta-carotene, vitamin C, vitamin E and magnesium were asso- ciated with significantly better hearing at both speech and high frequencies, compared with low intakes. The estimated joint effects were somewhat larger than the sums of the individual effects.
The researchers concluded that increased dietary intakes of antioxidants and magnesium seem to be asso- ciated with a lower risk of hearing loss. The discovery that the formation of free radicals in the inner ear is a key factor in hearing loss suggests that antioxidants may play a preventive or therapeutic role (2). Despite biological plausibility, only a few epidemiologic studies have examined the relations between antioxidant nutrients and hearing loss, and the results are not consistent (3). Possible reasons for null findings are that dietary assessment was misclassified or did not account for long-term intake or secondly, that imprecise outcome assessments, based on self-reports were used. Furthermore, antioxidants may be most effective when working together with other nutrients.
Hearing loss is a major public health concern affecting more than 36 million people (17% of the adult popu- lation) in the United States (4). 65% of Americans over 70 years of age have hearing loss and during the past 30 years a doubling of the number of Americans with hearing loss has been noted. According to the NHANES data, 90% and 37% of Americans have usual intakes of vitamins C and E below the Estimated Average Intake (5).
30 March 2011
Medical evidence on positive outcomes of fighting vitamin D deficiency has risen significantly in the past years.
1 May 2012
Observational studies and randomized controlled trials have examined the cardiovascular effects of fatty fish consumption and long-chain omega-3 polyunsaturated fatty acids (PUFAs) from dietary supplements. Several clinical trials have documented significant benefits of omega-3 fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), for cardiovascular health. Although much has been learned, some questions remain unanswered, including: what are the precise physiological effects and molecular mechanisms that account for the observed benefits for cardiovascular health; and what are the magnitudes and dose-responses of effects on specific diseases and the potential differences in various populations? National and international guidelines now give consistent recommendations for the general population: to consume at least 250 mg/day of long-chain n-3 PUFA or at least two servings of oily fish per week (1, 2).
15 February 2012
Insufficient dietary folate intake may be causally related to depressive symptoms in younger women, a new Japanese study suggests.
