Aging is unavoidable – it is a natural, physiological process that, although can be slowed down or covered up with cosmetic procedures, will happen to everyone. Aging is caused by a combination of genetics and lifestyle.
Genetics account for aging because of our cells dividing, resulting in our telomeres becoming shorter and shorter with each division. “Biological age…is related to the length of telomeres – stretches of DNA at the ends of chromosomes, which protect these precious packages of genes from daily wear and tear. We’re born with telomeres of certain length, and these get shorter as our cells divide, resulting in aging, scientists think” (Moisse, 2010). Aging occurs on a cellular level – eventually cells lose their ability to divide and repair themselves. This loss of capability to divide and repair is known as senescence. As the telomeres become increasingly shorter in the division process, there is the possibility that essential parts of DNA can be damaged with each new divide.
Lifestyle also accounts for aging. “…good habits, such as a healthy diet, regular physical activity and mental exercises that might keep the elderly vibrant through their golden years. The New England Centenarian Study, which includes 850 people entering their 100s, for example, has identified several behavioral and personality traits that seem to be critical to longevity, including not smoking, being extroverted and easygoing and staying lean” (Park, 2010). Taking care of your body can help maintain your youth, while engaging in risky lifestyle choices can speed up the aging process. Lack of exercise increases the risk of cardiovascular disease and diabetes, while smoking not only damages your lungs but also speeds up the rate at which telomeres decay and in turn age your body faster.
Another factor of aging is the relationship between good cholesterol – high-density lipoprotein (HDL) – and health. “HDL plasma concentrations decline with age in prospective studies. Decline in HDL concentration and function may occur secondary because of…specific aging processes [that] may be involved. Replicative aging, the telomere-driven loss of divisional capacity, is a species-specific aging mechanism that may decrease HDL concentration and function. Cross-sectionally, by contrast, HDL levels do not change much or even slightly increase with age, suggesting that only people with still high HDL concentrations survive” (Walter, 2009). People with higher levels of HDL tend to live longer because HDL removes the bad cholesterol – low-density lipoprotein (LDL) – from the body and helps decrease the risk of heart disease.
Moisse, K. (2010). Researchers identify genetic variant linked to faster biological
aging. Scientific American. Retrieved April 11, 2011 from http://www.scientificamerican.com/article.cfm?id=aging-telomere
Park, A. (2010). How to live 100 years. Time. Retrieved April 11, 2011 from
Walter, M. (2009). Interrelationships among HDL metabolism, aging, and
atherosclerosis. American Heart Association. Retrieved April 11, 2011 from http://www.atvb.ahajournals.org/cgi/content/full/29/9/1244
I like how you separated the ideas of lifestyle and genetics. That made the information much easier to imbide. I especially like how you explained the telomeres concept. Well done!
ReplyDeleteSam,
ReplyDeleteI think you did a particularly nice job on the paragraph in which you discuss how lifestyle affects aging; it was very thorough. Great work!