Unraveling the Mystery of Aging : Theories of Ageing and impact of Nutrition on longevity

This article provides an overview of different theories of aging, categorizing them into evolutionary theories and modern biological theories. Evolutionary theories explain why aging exists and why there are variations in lifespan among species. They suggest that external factors like predation and disease involved in determining the speed of senescent. Traditional evolutionary theories include mutation accumulation, antagonistic pleiotropy, and disposable soma theory. Modern biological theories are divided into programmed or genetic theories and damage or error theories. Programmed theories propose that senescent follows a biological timetable controlled by gene expression. They include the programmed cell death theory, endocrine theory, immunological theory, and telomere shortening theory. Damage theories suggest that environmental factors cause gradual damage to tissues over time, leading to aging. The wear and tear theory, somatic DNA damage theory, free radicals theory (or oxidative damage theory), cross-linking theory, and rate of living theory are important theories in this category. Among these theories, telomere shortening theory and free radicals theory have gained significant acceptance and are currently the focus of ongoing research. Telomere shortening theory suggests that as cells divide, their telomeres shorten, leading to cellular aging. The free radicals theory posits that oxidative damage caused by free radicals contributes to aging. Antioxidants are molecules that neutralize free radicals and are of interest in this field. Despite advances in understanding aging at the molecular level, the mechanisms that control human lifespan remain elusive. Theories of aging provide different perspectives, but none of them provide a comprehensive explanation. Ongoing research continues to explore the markers and processes of aging, with particular attention to telomere shortening and free radicals theory.