The process of aging is not entirely the function of genes. Related studies have found that only 20% of the aging process is related to genes. It is also largely related to environmental impact.
The aging time of different parts is inconsistent,
Vision: After the age of 30, people's vision began to change. The older you get, the worse the pupil's response to light changes. After the age of 60, the pupil size is only equivalent to 1/3 at the age of 20. At this time, the curvature of the lens becomes smaller, and turbidity may occur.
Hair: With the increase of age, the color and quantity of hair will change. Melanin in hair is mainly produced by melanocytes in hair follicles. After the age of 30, the melanin produced by hair follicle cells decreases. When the hair follicle no longer produces melanin, the hair turns white completely.
Brain: Before the age of 20, it is the most vigorous period of brain function. At the age of 40, memory begins to decline, and in the 70s, about13 people's memory will obviously decline.
Skin and nails (toenails): With the increase of age, the skin epidermis will become thinner, dry and lose its elasticity. The growth rate of nails (toenails) will slow down, lose luster and become Huang Yi brittleness.
Muscle: From the age of 30, the total muscle mass begins to decline, and by the age of 70, it will be reduced by at least 20% compared with the age of 30. In addition, the older you get, the worse your muscle strength is, which is related to the slow renewal of muscle fibers.
Skeleton: In a person's life, skeletal cells are constantly destroyed and regenerated. Most people start from the age of 30, the regeneration rate of bone cells slows down, and the bone mass and bone density decrease. This change is more obvious in postmenopausal women.