Are Telomeres the key to longevity?

We all age at different rates. Telomeres may be an indication as to why this fact might be true.

telomeres on chromosomes under a microscope

Elizabeth Blackburn, PhD., has done outstanding research in the area of telomeres. She and her UCSF colleagues are exploring a feature within cells that is a strong indicator as to why changes occur in telomeres . This is in the arena of cellular aging.

Dr. Blackburn indicates that within our cells, DNA is gradually slipping away. The DNA runs at different rates for different people. Sometimes it runs at different rates within the same individual at different times. Dr. Blackburn says that in some people it may defy time even running backwards with the aid of a key enzyme. That enzyme is telomerase.

Telomeres are attached to the ends of all 46 chromosomes in all of our cells. Once telomeres become too short, cells can no longer multiply to replenish body tissues. The progressive shortening of the chromosome capping, the protective bit of DNA, now appears to be associated with risk for certain chronic diseases. Studies even show that people with longer telomeres are more likely to live longer and even more significantly, to have more years of healthy life.

Over the past decade, Blackburn’s research group and others have found links between shorter telomeres and risks for cardiovascular disease, some cancers, depression, pulmonary fibrosis, vascular dementia, osteoarthritis and osteoporosis.

Twenty-six years ago, Blackburn who was then at UC Berkeley, and her then graduate student Carol Greider, now at John Hopkins University, discovered a new enzyme that they named telomerase. When active in cells, telomerase can lengthen telomeres and prevent chromosomes from being whittled down as cells repeatedly divide to replenish their numbers.

A little bit of telomerase activity may promote the health of certain types of cells. On the other hand, while the resulting longer telomerase in normal cells of the body help reduce the chances that one will get certain cancers, telomerase becomes abnormally active in well-established tumors. This super activated telomerase helps the already aberrant tumor cells become immortal.

However, telomerase is a double-edged sword, because it has the potential to fuel the growth of any cancer cells already lurking in the body. Dr. Blackburn’s ongoing studies include the habits of people who have longer telomeres. There are lifestyle factors that boost telomerase naturally. Exercise and a diet high in omega-3 fatty acids is one of the clearest examples. The type of exercise needs to be enough to make you break a sweat. Exercise mitigates the effects of stress and stress shortens telomeres. Stress reduction in the form of meditation helps people maintain the length of their telomeres.

For their discovery of telomerase and their studies of telomeres, Blackburn and Greider shared the 2009 Nobel Prize in Physiology or Medicine with another telomere researcher and collaborator with Blackburn, Jack Szostak of Harvard Medical School.

 

REFERENCES:

Aging, Chronic Disease and Telomeres Are Linked in Recent Studies. UCSF News Center– Jeffrey Norris on February 03, 2011. www.ucsf.edu/news.

 

The Youth Enzyme. Oprah magazine, Thea Singer, August 2012.