Air Pollution

Hong et al. (2016) investigated the mechanisms behind how particulate matter, which contains chemicals such as polycyclic aromatic hydrocarbons (PAHs), causes rhinitis. This was an in vitro experiment, but they found that in cells exposed to particulate matter, reactive oxygen species were increased, while superoxide dismutase, catalase, and glutathione
peroxidase were decreased. When the cells were given N-Acetyl-L-cysteine prior to the
exposure, the effect was not as strong. This suggests an impairment of phase II detoxification
pathways; the reactive oxygen species are the intermediate metabolites produced by phase I
reactions with the particulate matter, and phase II is not conjugating them quickly enough to
prevent tissue damage, so the antioxidant enzymes were getting used up.

The Mediterranean diet has been shown to help with glutathione (Dai et al, 2008). Specific foods included in this diet that are high in glutathione include oranges, strawberries, cantaloupe, peaches, avocado, asparagus, squash, pototatoes, okra, cauliflower, broccoli, tomatoes, meat, fish, and poultry, but only if fresh or frozen rather than canned (Jones et al., 1992). Vitamin C has also been shown to improve glutathione levels (Johnston et al., 1993), as has vitamin E (Costagliola et al., 1985). Dai et al., (2008) found the Mediterranean diet to be associated with lower levels of the oxidized form of glutathione, suggesting lower oxidative stress because of the beneficial antioxidants provided by the diet.

Some genotypes might require even more fruits and vegetables than others for their phase II enzymes to provide effective detoxification (Yuan et al., 2013). High tolerance for coffee indicates that CYP1A2 activity may be higher than average (Tian et al., 2019). This would contribute to a greater rate of production of the intermediate metabolites of PAHs (Rihs et al., 2005).

Mercury has also been found to deplete glutathione (Franco et al., 2009). Dental amalgams have been found to be associated with an increased risk for arthritis (Geier et al., 2021).
Barghi et al. (2012) found that women who ate more fruits and vegetables had lower levels of
mercury in their hair. They suggest that fiber can reduce the amount of mercury absorbed in the
intestine.

References:

Barghi, M., Behrooz, R. D., Esmaili-Sari, A., & Ghasempouri, S. M. (2012). Mercury exposure
assessment in Iranian pregnant women’s hair with respect to diet, amalgam filling, and lactation. Biological Trace Element Research, 148(3), 292–301.

Costagliola, C., Libondi, T., Menzione, M., Rinaldi, E., & Auricchio, G. (1985). Vitamin E and red
blood cell glutathione. Metabolism: Clinical and Experimental, 34(8), 712–714.

Dai, J., Jones, D. P., Goldberg, J., Ziegler, T. R., Bostick, R. M., Wilson, P. W., Manatunga, A. K.,
Shallenberger, L., Jones, L., & Vaccarino, V. (2008). Association between adherence to the
Mediterranean diet and oxidative stress. The American Journal of Clinical Nutrition, 88(5),
1364–1370.

Franco, J. L., Posser, T., Dunkley, P. R., Dickson, P. W., Mattos, J. J., Martins, R., Bainy, A. C.
D., Marques, M. R., Dafre, A. L., & Farina, M. (2009). Methylmercury neurotoxicity is associated with inhibition of the antioxidant enzyme glutathione peroxidase. Free Radical Biology and Medicine, 47(4), 449–457.

Geier, D. A., & Geier, M. R. (2021). Dental Amalgams and the Incidence Rate of Arthritis among American Adults. Clinical Medicine Insights: Arthritis & Musculoskeletal Disorders, 1–11.

Hong, Z., Guo, Z., Zhang, R., Xu, J., Dong, W., Zhuang, G., & Deng, C. (2016). Airborne Fine
Particulate Matter Induces Oxidative Stress and Inflammation in Human Nasal Epithelial Cells.
The Tohoku Journal of Experimental Medicine, 239(2), 117–125.

Johnston, C. S., Meyer, C. G., & Srilakshmi, J. C. (1993, July 1). Vitamin C elevates red blood
cell glutathione in healthy adults. American Journal of Clinical Nutrition, 58(1), 103.

Jones, D. P., Coates, R. J., Flagg, E. W., Eley, J. W., Block, G., Greenberg, R. S., Gunter, E. W.,
& Jackson, B. (1992). Glutathione in foods listed in the National Cancer Institute’s Health Habits
and History Food Frequency Questionnaire. Nutrition and Cancer, 17(1), 57–75.

Rihs, H.-P., Pesch, B., Kappler, M., Rabstein, S., Roßbach, B., Angerer, J., Scherenberg, M.,
Adams, A., Wilhelm, M., Seidel, A., & Brüning, T. (2005). Occupational exposure to polycyclic
aromatic hydrocarbons in German industries: Association between exogenous exposure and
urinary metabolites and its modulation by enzyme polymorphisms. Toxicology Letters, 157(3),
241–255.

Tian, D.-D., Natesan, S., White, J. R., Jr, & Paine, M. F. (2019). Effects of Common CYP1A2
Genotypes and Other Key Factors on Intraindividual Variation in the Caffeine Metabolic Ratio:
An Exploratory Analysis. Clinical and Translational Science, 12(1), 39–46.

Yuan, L., Zhang, L., Ma, W., Zhou, X., Ji, J., Li, N., & Xiao, R. (2013). Glutathione S-transferase
M1 and T1 gene polymorphisms with consumption of high fruit-juice and vegetable diet affect antioxidant capacity in healthy adults. Nutrition (Burbank, Los Angeles County, Calif.), 29(7–8), 965–971.