On top of that, he says, a test provides only an average telomere length across all of a cell’s chromosomes. It’s not entirely clear that such an average is important, since it is the shortest telomeres that are more relevant to disease.
Dr. Blackburn herself is careful to say that the mechanisms that may connect telomeres and telomerase to disease are not yet worked out, but says that clear associations are showing up in the data. She is now involved in looking at the telomeres of some 100,000 individuals though the Kaiser Permanente Research Program on Genes, Environment and Health. Among the early findings, she says, is that the longer past 80 a subject lives, the more likely he or she is to have longer telomeres than most.
Other work shows that the give and take between tearing down and building up telomeres includes a strong link to cancer. Cancer cells divide uncontrollably and certain types of cancer are linked to an overzealous production of telomerase. One avenue for shutting down tumour cells may be through inhibiting telomerase.
This also leads to the most speculative and tantalizing aspect of telomere science: that by enhancing telomerase production in normal cells the negative effects of telomere shortening can be thwarted and average lifespan – or at least healthy lifespan – can be extended.
Or to put it another way: A drug that enhances telomerase may do the same or better than healthy living, allowing us to have our cake, literally, and eat it too.
Current research in this area has focused on a telomerase activator called TA-65 with intriguing results. In 2011, a group of researchers at the Spanish National Cancer Centre found that TA-65 extends telomeres in mice without increasing cancer risk.
Most would say it is far too soon to know whether such work will lead to a genuine breakthrough or whether telomerase activators will eventually become as common as vitamin pills. Maria Blasco, who co-authored the study at the Madrid centre and who is also the chief scientific adviser to Life Length, another company that makes telomere tests, says, “It is likely that the first pharmacological telomerase activators will be used to treat diseases associated with extreme telomere shortening.”
Nevertheless, a cottage industry in telomere activation is already booming, mainly because TA-65 is a naturally occurring substance, extracted from Astragalus, a common herb. That means it is not regulated by the U.S. Food and Drug Administration, and so TA-65 can be ordered online.
Meanwhile, a couple weeks have passed and I’m back at the Executive Health Centre to get my results. To my pleasant surprise, I find my telomeres are slightly longer than average for someone my age.
My first thought is that I should thank my 91-year-old mother, who may have given me some good genetic armour that is counteracting all of my bad behaviour. My second thought is that this kind of anecdotal reasoning is precisely the sort of unscientific just-so story that is almost inevitable when one tries to explain a single point of data that is influenced by many hidden factors and may simply be random.
Dr. Chin says it’s what I do with the information in my approach to personal health that matters. And maybe telomere testing, at least for the time being, is an invitation to a bit of self-deception in service of a greater good.
Certainly I’ve become more aware that there’s an awesome and delicate machinery at work in every cell of my body. And even though I’m not entirely sure scientists know what it’s doing, I have to admit I’m less inclined to eat a doughnut and gum up the works. If Steve is shooting for 150, maybe I can aim a little higher too.
Guilt by association?
A sampling of recent studies show correlations between telomere length, disease, longevity and health risk factors...
- Heart disease: A study of more than 3,500 patients with heart disease showed that telomere length is a predictor of survival rates. (Anderson, et al, Circulation, 2013)
- Dementia: In 1,983 subjects older than 65, shorter telomeres have been associated with the early onset of dementia. (Honig et al, Journal of the American Medical Association - Neurology, 2012).
- Depression: The measurement of 1,063 subjects in Scotland correlated shorter telomeres with a history of depression in younger adults. (Phillips et al, Psychosomatic Medicine, 2013)
...but not always
- Diabetes: A study of 3,968 women in the Nurse’s Health study found no strong correlation between telomere length and Type 2 diabetes. (Du et al, Public Library of Science One, 2013)
- Obesity: A study of 439 overweight or obese women found 12 months of dietary weight loss and exercise did not change telomere length. (Mason et al, Obesity, 2013)