What Is It?
The thought of aging conjures some common perceptions: wrinkles, gray hair, a slightly stooped posture, perhaps some "senior moments" of forgetfulness. In fact, the process of aging has a nearly universal impact on our bodies, affecting our cells, tissues, organs, and body systems. The effects of aging can be seen in everything from our vital signs (like blood pressure) to our skin, to our bone and joints, to our cardiovascular, digestive, and nervous systems, and beyond. Some aging changes begin early in life. For example, your metabolism starts to gradually decline beginning at about age 20. Changes in your hearing, on the other hand, do not usually begin until age 50 or later.
We do not yet fully understand the complex interplay of factors that cause us to age as we do. Most likely, the vast and varied changes associated with aging result from a lifetime of environmental and cultural influences, as well as genetics, diet, exercise, illness, and a host of other factors, all of which contribute to the aging process.
A series of remarkable biological research studies since the 1990's have identified genes that can profoundly influence the rate at which cells, and animals, age. The good news from these studies is that biological changes that extend life also seem to extend vitality: animals that live longer remain quite healthy for most of their lengthened life. None of these discoveries is close to providing a "fountain of youth" for humans, but some scientists believe that research breakthroughs regarding aging in the 21st Century will lead to the development of drugs that can extend human life and simultaneously improve human health.