The research on aging
has been one of the ‘Hot Cake’ that researchers all over the world try to bake
in their laboratories, and people in general try to sniff the aroma coming out
of it, if not have the real bite.
Many leads on the aging research have come about
in last few decades but their translation into clinics has eluded thus far. A
couple of leads that I am going to discuss today are promising but have their
own pros and cons.
The first approach is associated with
telomere shortening. Telomere, discovered in 1970s, is the terminal part of the
DNA in chromosomes, which protects the chromosomes from degradation. However,
every time when a cell divides its DNA replicates. Due to an inbuilt mechanism with every
replication of DNA the length of telomere decreases, eventually exposing the
terminal genes to be inactivated or degraded leading to aging and other related
health problems.
A number of age-related diseases are associated
with short telomeres like Alzheimer’s disease.
The length of telomeres shrink due to many
reasons including very low levels of telomerase in most body cells, DNA
replication mechanism itself and a variety of stresses that one has to face
including emotional and environmental stress. Scientists have not found as yet
the full proof solution to solve this problem.
Interestingly enough, I had discussed in my
earlier write-up that somehow telomeres
in a man's sperm tend to get longer with age, which means that his children
will have longer telomeres to begin with and would live longer.
Scientists believe that if somehow the length of
telomere is prevented from decreasing, the life of the cells and the individual
with those cells could be extended. This is theoretically possible to achieve
by activating an enzyme called telomerase that is known to extend the length of
telomere.
However, practically increased telomere length
and over active telomerase makes cells immortalized and cancerous.
Consequently, question regarding which cells to be targeted when it comes to
protecting the telomere length is a complicated one.
Another approach is the use of antioxidants to defy
aging. Proponents of this approach believe that antioxidants may
help slow aging and prevent a number of aging-related diseases.
From
ancient times antioxidants have been advocated to have natural anti-aging
properties. It is believed that anti-oxidants not only slow down the aging but
also prevent many of the aging-related diseases.
Antioxidants are known to inhibit a
transcription factor called nuclear factor kappa B (NF-kB), which synthesizes
many inflammatory substances in body. Activated NF-kB has been implicated in
diseases such as cancer, diabetic, cardiovascular, Alzheimer’s disease and
other aging-related problems. It is thus understandable that inhibiting NF-kB
would slow the aging process. A new research seems to further strengthen this
claim.
Published in the journal Nature,
a study in mice suggests that NF-kB
becomes more active in the hypothalamus of mice as they get older. A mouse
lives for nearly 1000 days on an average. When researchers blocked the activity
of NF-kB, mice lived longer, roughly 1100 days. On the other hand, when they
activated this factor in mice, they lived only 900 days or less.
Although natural antioxidants
taken as fruits and vegetables have been found to lower the risk of some
chronic aging-related diseases or aging itself, only a few clinical trials
using antioxidants have shown anti-aging effects.
The synthetic antioxidants when taken have shown
adverse effects. Since NF-kB also plays important role in the body’s immune
response that fights against the bacterial and viral pathogens, its complete
inhibition using specific inhibitor could be detrimental.
Although there is no direct study linking these
two players in the aging process, it would be interesting to know whether
antioxidants somehow prevent telomere shortening. A study that I came across
suggests that telomeres are vulnerable to oxidative injury, and antioxidants
may prevent it from further damage.
Having said that, it is obvious that antioxidants
consumed as fruits and vegetables go a long way to protect from diseases and
may also slow down aging process.
Thus, for the common man like us it is prudent to
stick to our apples, berries, broccolis and carrots, and avoid antioxidant
drugs that claim to retain your youth and slow your aging. They may rather pace
it!!
