GPX1 encodes a member of the glutathione peroxidase family, which contains important antioxidant enzymes and helps detoxify hydrogen peroxide with glutathione, and thereby protect cells against oxidative damage. It protects the hemoglobin in red blood cells from oxidative breakdown.
The T allele leads to decreased enzyme function and has been linked to a disrupted anti-oxidative balance. T allele carriers are associated with increased risk for chronic disease, including certain cancers and coronary artery disease especially in the presence of a low fruit and vegetable intake, smoking, and high alcohol consumption. There is also evidence that T allele carriers have an increased risk of breast cancer with HRT use. Regular brazil nut intake, a rich source of selenium, has been shown to significantly increase the activity of the GPx1 enzyme in C allele carriers. One brazil nut contains approximately 70 mcg of selenium, (providing over 100% RDA).
Ensure a polyphenol-rich diet with a high intake of vegetables. Include brazil nuts
in the diet and other food-rich sources of selenium, such as sardines and turkey.
If selenium intake from food is poor, consider supplementation. It is important
to moderate alcohol consumption, and to rather drink red wine (due to higher resveratrol levels) as the alcohol of choice. Avoidance of toxin exposure, from heavy metals and pesticides as well as nitrates used as a food preservative, and cessation of smoking should be strongly encouraged. Women carrying the T allele should also be cautious of using HRT. Also, provide adequate intake of glutathione precursors (cysteine, glycine, and glutamic acid or glutamate) to support glutathione production.