“The genetics of ageing,” by Cynthia J. Kenyon, treats the aging process. Kenyon says the aging process is regulated by some pathways where aging-related signals are passing. According to the article, there are about seven possible pathways or other factors related with aging, which are Insulin/IGF-1 signaling, TOR signaling, AMP kinase, Sirtuins, inhibition of respiration, signals from the reproductive system, and Telomeres.
In the end of the article, Kenyon also mentions some mysteries that are unfound until now. For examples, scientists are not sure how aging occurs.They know aging related cells get damaged over time. But, they are not able to confirm it. After reading the article, three questions came up to my mind.
My first question is that what are age-related diseases? My next question is what causes physical aging; for example, people’s skins get wrinkled as they get older. The last question is if it is possible for human beings to live longer and how to prevent from aging. Alzheimer’s disease is a common age-related disease. In fact, my grandmother also struggled against Alzheimer’s disease until she passed away.
It is commonly known that there is neither a cure nor a known cause for this disease though many countries are investing lots of money into researches related with Alzheimer’s disease. An expert in this field also mentions the United States has spent lots of money due to Alzheimer’s disease, giving the estimated statistic from the National Institute of Health that 25 billion dollars were spent for this disease annually (Dippel). In addition to Alzheimer’s diseases, there are many other diseases assumed to have a relationship with ageing, such as cardiovascular diseases and cancers.But, why do people physically get old? For example, people will have wrinkled skins and grey hairs as they get older. According to a reliable website, it is assumed that skin winkles are caused by slow cell divisions due to ageing, which cause the layer of skins to be thinner (lifespan. org).
Genes and heredity account for 20-40% variation in human life span. Studies show that longevity results from the deficiency of harmful genes instead of life-extending genes. There is scarcity of literature on the influence of gene on healthy aging.Glatt and colleagues review showed that healthy-aging genes were linked to the disease process of inflammation (interleukin-6), aplipoprotein E APOE and metabolism. Author also relates genetic factors with environmental factors. Certain environmental factors can modify inner process of genetic functions that would slows down aging process.
The study of MacArthur is cited in which higher educational accomplishment may alter the effect of APOE on aging process and risk of cognitive decline is reduced.Hence certain environmental factors can modify specific gene functions. Other biological mechanism proposed is stressful aging. Stress play key role in accelerating aging process. Large number of studies have confirmed that stress puts negative effect on physiological process. Stress induces certain cardiovascular and neuroendocrine assays that are indication of hypothalamic-pituitary-adrenal (HPA) activation.
Authors propose higher allostatic load will promote aging and disease process and vice versa.Hence, those who are resistant to stress are more likely to age successfully. Cognitive brain function is also linked with the aging process. Keeping mind active by attaining high level of education, active in occupation and performing challenging tasks that keep minds active may keep cognitive brain function healthy. In a study on rats and humans it has been found that N-methyl-d-aspartate receptor characteristics change in the aging brains when they long-term memory is maintained. This indicated that aging brain has the capacity to learn more.