This slows down the body's processes and the body begins to age. Oxygen radicals accumulate in the body and damage it. The organs eventually stop working. The mechanism in the body that synthesizes proteins ceases to work well. Faulty proteins are developed and cause damage to cells, tissues, and organs.
Genes mutate as the body ages, causing cells to malfunction and deteriorate.
Experts used to believe that chronic disease and disability always accompanied aging. Now it is known that much disease can be prevented or controlled. A person's lifestyle can help prevent or lessen the effect of many causes of disease. The three leading causes of death among people in developed nations are heart disease , stroke , and cancer . The medical community understands a great deal about how to prevent death from these causes.