Ageing is an unavoidable reality of life irrespective of gender and race. It is a complex process involving genetic, hormonal and environmental mechanisms. One of the major theories regarding ageing is free radical theory, or oxidative stress.

http://www.newindianexpress.com/cities/chennai/2017/nov/22/when-grey-and-you-are-not-besties-heres-how-you-cover-it-1708497.html