What is smoking signature?
Tobacco smoke contains many chemicals that the body has to process and clear. The lungs, blood vessels and immune system are all exposed, and the body responds by adjusting how certain genes are used. A smoking signature refers to that response as it appears in your epigenome. It can reflect active smoking, past smoking and, in some cases, regular exposure to secondhand smoke. It is a measure of exposure, not of health outcomes.
How your genes play a role
Smoking is one of the strongest and most consistently studied influences on DNA methylation. Researchers have identified specific methylation sites that shift in people exposed to tobacco smoke. Some of these marks begin to move back toward typical levels after a person stops smoking, while others can persist for years. Reading these sites together gives an index of how much smoke exposure your cells appear to reflect.
Self-reported smoking history can be hard to quantify, especially for occasional smokers, former smokers or people around smoke at home or work. An epigenetic signature offers an objective view of how your body has registered that exposure. For former smokers, it can be encouraging to watch the signature change over time. For anyone, it adds useful context to conversations with a clinician about lung, heart and overall health.
What your report shows
Your Smoking Signature results are explained in plain language in your private EvoDNA account, alongside the other areas in your kit.
- Exposure indexAn estimate of how much tobacco smoke exposure your methylation patterns appear to reflect.
- Past versus presentContext on whether your profile is consistent with ongoing or earlier exposure.
- Secondhand contextA signal that may reflect regular exposure to other people's smoke.
- Recovery over timeWith repeat testing, a view of how your signature shifts after reducing exposure.
Each result comes with a plain-language explanation and practical points to discuss with your clinician.
Illustration only. Your report reflects your own genetic results.
Putting results to use
Many people use their results as a starting point for conversations with their clinician about:
Clinicians can offer approaches and resources that make stopping smoking more manageable.
Keeping your home and car smoke-free may reduce secondhand exposure for everyone.
Regular aerobic activity is often discussed as support for breathing and circulation.
Some epigenetic marks change slowly, so steady habits matter more than quick results.
Questions
I quit years ago. Will this still show?
It may. Some smoking-related marks fade relatively quickly after quitting, while others can persist for a long time. Your results can show where your profile currently stands.
Can secondhand smoke affect my results?
Research suggests regular secondhand exposure can influence some of the same methylation sites. The effect is usually smaller than with active smoking.
Does this measure my lung health?
No. This index reflects smoke exposure as seen in your methylation patterns. It is not a test of lung function or a diagnosis of any condition.
