ability of vitamin E to help fight respiratory tract infections in the
elderly may be impacted by a person’s sex and their genetics, suggests a
Writing last month in the American Journal of Clinical Nutrition, the authors set out to investigate why vitamin E supplementation is more effective at reducing infection in some people than in others.
The elderly generally have an increased risk of infection and RIs are common amongst nursing home residents. Using data from a vitamin E intervention in a nursing home, the researchers set out to examine whether the effects of vitamin E on these infections might be partially due to genetic differences at cytokine genes, and whether sex played any part on the interaction.
The trial, which had been conducted between 1998 and 2001, involved 617 participants with an average age of 85. Out of these, 500 participants agreed to DNA tests, and 451 completed the study. The majority were white and female.
Participants were randomly assigned to receive either vitamin E or placebo daily in addition to a multivitamin containing half of the Recommended Dietary Allowance of essential vitamins and minerals, including 4 IU vitamin E.
In their analysis of the data, the authors of the current study tested if sex, vitamin E and specific DNA sequence variations (single nucleotide polymorphisms (SNPs)) were associated with respiratory tract infections.
The researchers discovered a three-way interaction between vitamin E supplementation, sex and certain genotypes.
Their results suggest that the recommendations for vitamin E supplementation as a preventive measure against RIs should consider genetics and sex. These observations may have ramifications for public health through improved predictions of infection in the elderly and help to identify individuals who may benefit the most from taking supplemental vitamin E.