The aging process starts at the age of 35 and becomes more evident after 40. The passage of time and our way of life make our body begin to lose its renewing power; that's when aging appears with all of its symptoms. Aesthetically, with wrinkles and other external signs, and beginning symptoms: fatigue, loss of mental clarity, changes in body composition ( such as decreased muscle mass), decreased sexual desire, and joint pain, among others. Also the appearance of diseases that can turn off our energy and health, subtracting years from lives.
From the scientific point of view, aging is the result of cellular and sub-cellular damage that occurs with time (Nobel Prize medicine 2009). This is the cause of the onset of diseases associated with age, such as cardiovascular, neurodegenerative diseases including dementia, Alzheimer's and Parkinson's disease, cancer, diabetes, osteoporosis, osteoarthritis and many more leading to the end of our lives.
Most people in the history of humanity have not died of "old age," but as a result of infectious epidemics, violent deaths and malnutrition. But over the last century, diseases related to aging (such as cancer, cardiovascular, diabetes, etc.) are the leading causes of death in developed societies. These are directly related to life habits (stress, food, lack of exercise...) and the decline of a series of metabolic and hormonal biomarkers that lead to cellular and subcellular deterioration.
Acting on the causes described above can avoid, slow down, and even reverse these changes to prevent diseases and therefore improve our quality of life. Thus preserving our functionality, regardless of chronological age.