S01-03 The Impact of Lifestyle on Telomere Length: Exploring the Effects of smoking, vaping and alcohol consumption

Healthy ageing is promoted by the adherence to beneficial habits and activities. Nonetheless, there is limited knowledge on the extent to which – age, sex, or race and ethnicity influence the correlations between lifestyle and behavioural factors such as smoking, vaping, and alcohol intake and relative telomere length (RTL), a potential biomarker of ageing.

Telomeres are protective DNA-protein complexes located at the ends of chromosomes that diminish in length with each cell division, and toxicological exposures might accelerate this reduction, causing genomic instability.

Telomere length (TL) is thus recognized as a biomarker of cellular aging and cumulative DNA damage relevant to toxicology. Recent discoveries demonstrate the impact of smoking, vaping, and alcohol intake on telomere length through pathways of oxidative stress, inflammation, and DNA damage. Cigarette smoking is consistently associated with shortened TL, as smokers have significantly shorter leukocyte telomeres than non-smokers. Tobacco smoking produces reactive oxygen species that induce telomeric DNA breakage and persistent inflammation, accelerating telomere degradation. Recent research suggests that electronic cigarette vaping may also lead to telomere erosion. E-cigarette aerosols have less hazardous byproducts than tobacco smoke; yet, can still generate oxidative stress. Cellular studies indicate that e-cigarette vapours cause DNA damage and telomere dysfunction similar to that of conventional smoking. Therefore, vapers may undergo telomere shortening similar to smokers, but the degree is still being investigated. Chronic excessive alcohol consumption is linked to a decrease in telomere length. Individuals with alcohol use disorders have significantly reduced telomere length compared to healthy controls, a phenomenon likely ascribed to oxidative stress and chronic inflammation generated by ethanol, while moderate consumption without misuse seems to exert negligible impact on telomere length.

These findings highlight the toxicological relevance of telomere dynamics as an indicator of lifestyle-related cellular ageing and emphasise the necessity of ongoing studies to determine causality and guide public health actions.