Oxidative Stress, the Damage-Accumulation Theory of Skin Aging, and the Role of Antioxidants in the Future of Topical Skin Protection

The major cause of skin aging is a lifetime of damage accumulation from oxidative stress. This scientific review looks at the effects of both internal and external sources of oxidative stress: intrinsic oxidative stress from toxic free radicals produced as a result of cellular metabolic energy production, and extrinsic oxidative stress as a result of continuous exposure to a toxic environment and poor lifestyle choices. In this article, the most toxic free radicals are reviewed, and understanding of the role of molecular oxygen as a toxic, pollutant, mutagenic, biradical, dangerous, poisonous gas is discussed. The importance of antioxidants, their capacity to inhibit skin aging, and an in-depth look at various quantitative methods (eg, oxygen radical absorbance capacity, environmental protection factor, Trolox) for determining topical antioxidant skin protection capacity are reviewed.