Sunlight, diet and pollution – Effects on oxidative stress and skin ageing
CATHERINE A. BONN1, KHIMARA NAIDOO1, HELENE A. HINE2, MARK A. BIRCH-MACHIN1*
*Corresponding author
1. Dermatological Sciences, Institute of Cellular Medicine, Newcastle University, Newcastle, United Kingdom
2. Croda Europe Ltd, Snaith, United Kingdom
Abstract
Skin is subject to stress from external factors, which have the potential to cause premature ageing. Oxidative stress from the generation of reactive oxygen species has been increasingly implicated as a driving force in skin ageing, leading to loss of skin structure and function. While intrinsic skin ageing driven by genetics is inevitable, our exposure to some of the extrinsic factors that affect the process is under our influence. Sunlight, diet and pollution can all affect the oxidative environment of the skin. This review details the current research into the effects of these factors on oxidative stress in the skin.
INTRODUCTION
Ageing is a process in which losses of structure and function accumulate over time. This leads to a reduction in the capability of an organism to cope with stress from the environment and function in a normal capacity. This process is observed in all animals, and while average human lifespan has been extended in recent years by modern healthcare knowledge, we are still susceptible to the effects of aging over our lifetime. However, the exact underlying biological causes of the ageing process remain unclear.
Skin, the largest organ in the body, is the barrier that protects us from external insults. Ageing in the skin is influenced by both intrinsic and extrinsic factors. Intrinsic ageing refers to changes in physiology which are mainly influenced by genetics. In the skin this manifests as an increase in roughness, redness due to visible vasculature, a reduction in elasticity seen as an appearance of fine lines and atrophy causing a reduction in apparent plumpness (1). Extrinsic ageing is caused by insults to the skin including sunlight exposure, smoking and pollution. These damage the skin by causing secretion of pro-inflammatory signals, dir ...
