Smoking Leaves Footprint On Your DNA, Even After You Quit

'An impact that can last more than 30 years.'

Everyone knows that smoking is bad for your health, but scientists have now revealed that smoking leaves a ‘footprint’ on your DNA that stays long after you quit.

A new study has shown that smoking causes DNA methylation – a cellular process, which modifies the function of DNA – in as many as 30% of genes in the human body.

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Quitting will benefit your health in other ways, even three decades after stopping, some smokers still had persistent methylation sites in numbers never seen in non-smokers.

Professor Roby Joehanes said: “Our study has found compelling evidence that smoking has a long-lasting impact on our molecular machinery, an impact that can last more than 30 years.”

Although the majority of methylation sites had returned to normal levels within five years of quitting smoking, those that remained were criticial.

Lead author Stephanie J. London explained that these findings are significant because the methylation sites that most commonly remained were linked to specific genes associated with diseases such as chronic obstructive pulmonary disease and cancer.

The study, which looked at 16,000 participants, established this important link between altered gene sites and potential risk of future diseases.

If these smoking-related DNA methylation sites can act as biomarkers, they can potentially develop new therapies and treatments for smokers against deadly diseases.

London said: “These results are important because methylation, as one of the mechanisms of the regulation of gene expression, affects what genes are turned on, which has implications for the development of smoking-related diseases.”

Smoking kills 96,000 people in the UK every year from smoking, and is the leading cause of preventable deaths worldwide.