The collagen in the skin is affected by age in various ways. The skin becomes thinner and drier, and develops sags and wrinkles due to the collagen and elastin becoming disconnected. Says, Dr. Jeffrey Spiegel, M.D. In his Article: What is collagen and what happens to it when we age?

Dr. Spiegel also states:

Growth of new cells slow down dramatically.
Dull colored skin can occur as the dead cells do not shed as quickly.
Aging skin is more susceptible to the development of brown spots on the face and body.
Intrinsic aging (hereditary) Extrinsic aging (caused by tobacco and environmental

factors).

5. Smoking-contains chemicals that stimulate collagen-destroying enzymes and slows down the cells

which produce collagen by 40%.