W
W
To answer questions about why and how we age, some scientists look for mechanisms or W.
pathways in the body that lead to aging. Our cells constantly receive cues from both inside and GENOME.
outside the body, prompted by such things as injury, infection, stress, or even food. To react and adjust to these cues, cells send and receive signals through biological pathways. Some of the GO
most common are involved in metabolism, the regulation of genes, and the transmission V
of signals. These pathways may also be important to aging.
BIOLOGY OF AGING: RESEARCH TODAY FOR A HEALTHIER TOMORROW 5
generally does not change much after age 30.
occurs, and what are the biological processes
People who are cheerful and assertive when
underlying these changes. Scientists look
they are younger will likely be the same when
deep into our cells and the cells of laboratory
they are age 80. The BLSA finding suggests
animals to find answers. What they learn today
that significant changes in personality are not about aging at the cellular and molecular due to normal aging, but instead may be early levels may, ultimately, lead to new and better signs of disease or dementia.
ways to live a longer, healthier life.
The rate and progression of cellular aging
can vary greatly from person to person. But
Living long and wel : Can we
generally, over time, aging affects the cells of
every major organ of the body. Changes can
do both? Are they the same?
start early. Some impact our health and func-
tion more seriously than others. For instance,
You can hardly turn on your computer these
around the age of 20, lung tissue starts to lose
days without being bombarded with adver-
elasticity, and the muscles of the rib cage slowly
tisements that pop up trying to convince you
begin to shrink. As a result, the maximum
of the power of a pill that will make you live
amount of air you can inhale decreases. In the longer or a cream that will help to revive your gut, production of digestive enzymes dimin-youthful vigor and appearance. The search for
ishes, affecting your ability to absorb foods
properly and maintain a nutritional balance.
Blood vessels in your heart accumulate
fatty deposits and lose flexibility to varying
degrees, resulting in what used to be called
“hardening of the arteries” or atherosclerosis.
Over time, women’s vaginal fluid production
decreases, and sexual tissues atrophy. In men,
aging decreases sperm production, and the
prostate can become enlarged.
Scientists are increasingly successful at
detailing these age-related differences because
of studies like the BLSA. Yet studies that
observe aging do not identify the reasons for
age-related changes, and, therefore, can only
go so far toward explaining aging. Questions
remain at the most basic level about what
triggers aging in our tissues and cells, why it
6