One More Reason To Say No To Tobacco

One More Reason to Say No to Tobacco

World No Tobacco Day is observed on 31 May every year. Tobacco use is the single largest preventable cause of death globally — responsible for more than 8 million deaths per year. In India, tobacco use (smoking and smokeless) affects approximately 267 million adults. And now, there is one more compelling reason to say no: the impact of tobacco on your DNA.

How Tobacco Damages Your DNA

Tobacco smoke contains more than 70 known carcinogens — chemicals that directly damage DNA. These carcinogens cause mutations in tumour suppressor genes (like TP53 and CDKN2A) and oncogenes (like KRAS and EGFR) that drive the development of cancer. Tobacco-related DNA damage accumulates over time, which is why the risk of cancer increases with the duration and intensity of smoking.

Tobacco use is causally linked to cancers of the lung, mouth, throat, oesophagus, stomach, pancreas, kidney, bladder, cervix, and blood (leukaemia) — as well as cardiovascular disease, COPD, and stroke.

The Genetics of Tobacco Susceptibility

Not everyone who smokes develops cancer — and not everyone who develops lung cancer smokes. Genetic variants influence individual susceptibility to tobacco-related disease. Variants in genes including CHRNA5, CHRNA3, and CHRNB4 influence nicotine dependence and smoking behaviour. Variants in genes encoding carcinogen-metabolising enzymes (CYP1A1, GSTM1, NAT2) influence how efficiently your body detoxifies tobacco carcinogens — affecting your cancer risk.

Quitting: The Best Decision You Can Make

The health benefits of quitting begin within 20 minutes of the last cigarette. Within 10 years of quitting, the risk of lung cancer falls to about half that of a smoker. It is never too late to quit — and understanding your genetic risk profile can provide powerful motivation.