All cells and organs in your body are not the same age when it comes to function. You can easily see the effects of lifestyle and environmental factors driving aging and chronic illness on your skin. You can see that this hand looks old. The skin is thin. It is fragile. It tears easliy. Minor bumps cause bleeding. Those changes can be simply due to age, but even in 70 year-old individuals, the skin under clothing—the skin that is protected from the sun—looks much younger. If an individual loves sun bathing and smokes, these changes can come at a much younger age. If a more youthful appearance is important to you, the best thing you can do is protect your skin from the sun and avoid cigarettes.
This skin is an organ that doe not simply look older because of sun damage, it is older. It may has come into existence at the same time as the rest of the body, but in a functional sense it is really older. The chromosomes, genes, and signaling pathways function like older tissue. The chonological and physiological ages become different in the same person.
Telomeres are structures at the end of chromosomes that protect those genetic packages. They are longer in young individuals and shorter in older people. Oxidants build up with aging and they damage telomeres and shorten them. Telomere shortening is associated with mortality, aging-related diseases, and aging itself. Normal aging is associated with telomere shortening, and studies on genetically modified animal models suggest causal links between telomere erosion and aging. Cells with shorter telomeres are functionally older and more susceptible to cancer. Sun damaged skin has shorter telomeres compared with protected skin and other organs. It is in fact older and more susceptible to cancer. As with the other aging and chronic disease issues we have discussed, excess oxidants from sun exposure play a key role here.
You can easily see that organs and cells in the same person can age at different rates. You can also understand that you can do something about it. You can have more youthful appearing skin for a long time. You can slow aging and delay chronic illness now. Sorry for the technical difficulties the last two days
The irony is that when I was a young woman growing up in the Midwest, the thing we did was get a suntan, which in retrospect may have been a very unwise pursuit.