HUMAN MEDICAL BIOLOGY, ANATOMY, PHYSIOLOGY AND PATHOLOGY - Ya.I. Fedonyuk 2010

BIOLOGY

CHAPTER 1. BIOLOGICAL FOUNDATIONS OF HUMAN VITAL ACTIVITY

1.4. ONTOGENETIC LEVEL OF ORGANIZATION OF LIFE

1.4.3. Biology of Individual Development

Life Span and Longevity Issues

The lifespan of individual species is genetically determined. No matter how ideal the conditions created for laboratory mice may be, they live no longer than 3–3.5 years, with distinct short-lived and long-lived strains. Environmental factors significantly influence average life expectancy, whereas maximum lifespan is extremely difficult to alter. Human average life expectancy has varied across different epochs. Judging by skeletal remains, about 40% of Neanderthals died before the age of 14, 15% between 15 and 20 years, and only 5% at the age of 40 or older. People of the Stone Age also rarely survived to 50. For millennia, humans died without reaching old age. Early infant mortality, mass epidemics, famine, and harsh living conditions continued to curtail average life expectancy in subsequent centuries. Currently, the average life expectancy is 71.1 years in economically developed countries and 52.2 years in developing nations. Moreover, women live an average of 3–5 years longer. Although advancements in medicine and improvements in socio-hygienic living conditions have nearly doubled average life expectancy in developed countries, the maximum human lifespan has remained virtually unchanged.

A distinction is made between chronological (calendar) and biological (physiological) age. Individuals whose chronological age has reached 60–74 years are referred to as elderly, those aged 75–89 as senile, and those over 90 as centenarians. Biological age often does not correspond to calendar age. Its assessment is based on a set of tests (the state of the cardiovascular, respiratory, and nervous systems, The ability to withstand physical exertion, etc.). Life expectancy is the result of the interaction between external and internal (genetic) factors. Given the complex nature of how genetic and environmental factors influence the Aging process, it is not easy to determine just how long a person can live. If calculations are based on the premise that the average lifespan of mammals is 5–8 times the duration of their pre-reproductive period, and the human pre-reproductive period is taken as 20–25 years, then the biological lifespan could exceed 100 years and even approach 150–200 years.

The mission of biology and medicine is to seek ways to prevent the decline of functional activity and maintain the health of individuals who have crossed the threshold of 55–60 years of age. This task can be resolved not only on a biological basis, but also by taking into account social factors, which are of great importance to humans. Factors that increase life expectancy include: 1) physical activity (moderate physical labor, physical culture, and sports — there are no lazy people among centenarians); 2) rational Nutrition and a reduction in caloric intake; 3) The Use of antioxidants — substances that inhibit The Development of age-related pathology and reduce

the frequency of Mutations (Vitamins E, A, B-complex, P, Amino Acids such as glutamic acid, Cysteine, Methionine, and Other Compounds);

4) a healthy lifestyle based on recognizing the inextricable unity of Nature and Humanity; 5) the replacement of diseased Organs or Cell complexes.