In his critical book entitled “Why We Age-and Why We Don´t Have To”, genetics professor at Harvard Medical School Dr. David Sinclair defines telomeres as a cap that protects the end of the chromosome from attrition, analogous to the aglet at the end of a shoelace or a burned end of a rope to stop it fraying. It is well established that as we age, telomere length shortens. After telomeres shorten to a certain length, a cell stops dividing and becomes senescent. Consequently, telomere length is a crucial biomarker of ageing.
If telomere length is such a major biomarker of ageing, we may ask ourselves: can we, through lifestyle changes and diet (including intermittent fasting), increase telomere length and/or decrease the rate of telomere shortening? There has been mounting evidence that the answer to this question is yes! The focus of this particular article is to explore and summarize the relationship between exposure to all kinds of environmental toxins and telomere length. Future articles will discuss the impact and effect of lifestyle changes and diet on telomere length.
Environmental toxins include: air pollution, pesticides, ionizing radiation, heavy metals, among others. Reports that several air toxics, such as benzinidine, were associated with shorter relative telomere length.  Findings suggest an association between occupational exposure to pesticides and shorter telomere length.
In conclusion, there is mounting evidence that environmental toxicity, in all its sources and forms, a risk factor which surrounds us everyday, shortens telomere length and, thus, negatively impacts our healthspan and lifespan. It is of paramount importance to try to avoid such exposure as much as possible and to find detoxifying strategies to eliminate or reduce substantially this toxic burden from our bodies (blood, tissues and cells).
 Lifespan: Why We Age – and Why We Don’t Have To. Book by David A. Sinclair PhD.