Oxidative stress and your skin-defence genes

Oxidative stress is the slow rust of skin ageing. Sunlight, pollution and inflammation all generate reactive oxygen species, and your skin’s defence is only as strong as the genes that run it.

The oxidative-ageing axis

When the production of reactive oxygen species (ROS) outpaces your skin’s ability to buffer them, damage accumulates in lipids, proteins, DNA and the collagen matrix. Over years that drives wrinkles, loss of elasticity, uneven pigmentation and slower repair. The buffering capacity is largely genetic.

Five genes working in sequence

Your antioxidant defence is a relay. SOD2 converts dangerous superoxide from your mitochondria into hydrogen peroxide. GPX1, a selenium-dependent enzyme, then turns that hydrogen peroxide into harmless water. In parallel, the glutathione S-transferases GSTM1, GSTT1 and GSTP1 neutralise reactive electrophiles such as oxidised fats. Each step depends on the one before it.

Where the weak links appear

Common variants weaken several of these steps. GSTM1 and GSTT1 are frequently missing entirely (a “null” genotype), so those carriers have less detox reserve. SOD2 and GPX1 variants alter how efficiently each enzyme works. Because the genes act in sequence, a weakness anywhere in the chain lets oxidative damage through.

What actually helps

The most pathway-aligned support is a network, not a single nutrient: vitamins C and E as front-line antioxidants, alpha-lipoic acid which regenerates other antioxidants, and the enzyme cofactors zinc and manganese (manganese feeds SOD2 directly). For GPX1 specifically, adequate selenium is essential, which is its own Gene Story.

The science, in depth

Intrinsic ageing combines with UV, pollution and inflammation to generate ROS that overwhelm buffering capacity. SOD2 (MnSOD) dismutes mitochondrial superoxide to H₂O₂; GPX1 couples H₂O₂O₂ and lipid hydroperoxides to glutathione; GSTM1/GSTT1/GSTP1 conjugate reactive electrophiles for phase-II clearance. GSTM1/GSTT1 null deletions remove enzyme expression outright, while SOD2 and GPX1 polymorphisms grade enzyme efficiency, so the network phenotype reflects the sum of all five loci.