Every day, cells in different tissues are prone to damage. The older, damaged cells are eventually replaced by new ones to maintain tissue health. With progressing age, tissues lose their regenerative capacity, accruing damage. For example, by age 50, active hair follicles become fewer. Hair fall continues, but very few new hairs are generated, leading to hair thinning and baldness. Aging is also accompanied by reduced metabolism, reduced physical activity, and hormonal changes that gradually lead to the loss of muscle and bone mass. As bones, joints, and skin age, connective tissues produce lower levels of collagen and elastic fibers. This reduces their strength and elasticity, causing brittle bones and wrinkled skin. Furthermore, the proteoglycan composition of cartilage changes with age. As a result, cartilage flexibility and shock absorption capacity decrease leading to diseases such as osteoarthritis. With increasing age, the possibility of DNA damage and mutation increases, making cancer more common in the elderly.