LIVING THE ZONE: Physical IV
How old am I really?
People usually judge age by counting the years that they have lived, some by looking at outward physical appearance and some others by measuring biomarkers within the body, like cholesterol and glucose concentrations which are known to increase as one gets older. There are institutions that profess to being able to give an estimation of a person’s “real age” by taking a combination of the above factors and then obtaining an idea of one’s risk factors for chronic disease and puttying them all into an equation which spits out an age estimation which may be different to ones chronological age.
I tried one of these online calculators recently and was upset to find out that thanks to my higher than normal cholesterol concentration, the computer deemed me to be three years older than my chronological age!
But the real answer to determining our real age may be just a blood test away and may be a reality in the not too distant future. A blood test, which can show how fast the ageing process is occurring, and offers the possibility of estimating the time left to live, will go on sale in some countries this year.
This test measures the length of a structure called a telomere. The human telomeres form cap-like structures at the ends of cell’s chromosomes and they prevent the genetic material from fraying. Telomeres get progressively shorter each time the cell divides until they become so short that the cell dies. The test, which is priced at about $500, will measure the telomere length, which is believed to be one of the most accurate indicators of the speed of ageing.
My interest in telomeres surfaced as we recently published a scientific paper, which documented that athletes who experienced chronic fatigue and had participated in many years of high-mileage and high-intensity exercise were found to have significantly shortened telomeres in their skeletal muscle. This paper was one of the more recent publications showing that too much exercise may not be good for the body, and raised the possibility of over-exercise. Whilst, the amount of exercise that the group studied in this paper was enormous and unlikely to be attained by the most committed fitness fanatic, it did raise our awareness that an experienced physician should carefully evaluate athletes who experience fatigue after many years of high-mileage exercise.
Whilst the telomere length investigation might give us further insight and add to our existing battery of risk-factor tests for many diseases including cardiovascular disease and Alzheimer’s, there are some drawbacks…
There are some people who are born with short-telomeres who have short life-spans but we don’t know if people with long telomeres necessarily have a longer life-spans. Furthermore the life insurance industry or those in the industry of marketing anti-ageing products might use the test results unethically. Most importantly, humans have a built in system called telomerase, which rebuilds these cap-like structures, and scientists are busy determining the effects of our lifestyle choices, like exercise and smoking or even certain medications on human telomerase. Indeed, there is preliminary evidence to show that exercise training in healthy amounts (see my blog “How much is enough?”) stimulates telomerase and therefore telomere length!
So, as science is yet to fathom exactly how accurate the test is and how to fully interpret the tests meaning, I am not about to get mine measured just yet, but this will surely be an important test to have measured sometime in the future.