Subscribe to the BioNews newsletter for free

Login
Advanced Search

Search for
BioNews

Like the Progress Educational Trust on Facebook


 


 

Smoking can leave epigenetic changes on DNA for 30 years

26 September 2016

By Dr Ashley Cartwright

Appeared in BioNews 870

Research has found that smoking can leave long-lasting epigenetic changes on the genome.

'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,' stated Dr Roby Joehanes of Beth Israel Deaconess Medical Center and Harvard Medical School in Boston, lead author of the study, which was published in Circulation: Cardiovascular Genetics.

Scientists know that former smokers are at increased risk of developing some cancers and heart diseases, but the mechanisms responsible have been unclear. This study suggests that epigenetic changes, which occur within the genome and influence gene activity without changing the DNA itself, are a possible cause of this.

The researchers focused on patterns of DNA methylation across the genome in 15,907 patient samples across 16 cohort studies. Methylation is an epigenetic process which cells use to control gene activity. The cohorts comprised 2433 current, 6518 former and 6596 never smokers. Current smokers were defined as patients who said they smoked at least once a day sometime over the last year, while former smokers were individuals who had stopped at least one year before blood samples for the investigation were obtained.

The genomes of current smokers showed 2623 sites of DNA methylation, compared to never smokers. The authors suggest that this corresponds to 7000 potentially affected genes, approximately a third of the human genome. Furthermore, many of these genes have been associated with smoking-related disease traits including pulmonary function, cancer, inflammatory disease and heart disease.

'We don't really know whether it means "damage" to the DNA,' said senior author Dr Stephanie London, chief of the Epidemiology Branch at the National Institute of Environmental Health Sciences in Research Triangle Park, North Carolina. 'That requires more study, using data outside what we have here. What we're saying is that it's a change to your DNA that can have a downstream effect on what genes are expressed at what levels.'

Additionally, comparison between former and never smokers identified differences in DNA methylation at 185 sites across the genome. As found previously, the strongest differences occurred at sites associated with smoking-related disease traits. In some individuals, this difference was present 30 years after cessation of smoking.

Given the large number of genes potentially affected, the research did not focus on individual gene changes and the possible health effects. Future investigation is likely to focus on the potential therapeutic implications of these findings to target prevention and treatment of tobacco-related disease. Alternatively, these findings could be used to develop diagnostic tests to evaluate the health effects of a patient's smoking history, or help rule out smoking as a cause in other studies of environmental influences on health.

SOURCES & REFERENCES
Circulation: Cardiovascular Genetics | 20 September 2016
 
Science Daily (press release) | 21 September 2016
 
Mail Online | 20 September 2016
 
Reuters | 21 September 2016
 
WebMD | 20 September 2016
 

RELATED ARTICLES FROM THE BIONEWS ARCHIVE

17 July 2017 - by Isobel Steer 
Mothers who smoke during pregnancy have daughters who are more likely to experience miscarriages...
07 November 2016 - by Dr Özge Özkaya 
For the first time scientists have quantified the number of mutations caused by the number of cigarettes smoked in a lifetime...
10 October 2016 - by Dr Ashley Cartwright 
A person's 'epigenetic age' can predict how long they will live, according to a study of over 13,000 individuals...

04 July 2016 - by Lone Hørlyck 
A study of smokers has found smoking damages their sperm, including their DNA and mitochondria, by triggering inflammatory processes in their semen...
31 May 2016 - by Rachel Reeves 
A research review suggests that cannabis use damages DNA, and claims that this damage can be inherited...
04 April 2016 - by Dr Rachel Brown 
A large international study has revealed that smoking during pregnancy may chemically alter the DNA of the developing fetus...
07 December 2015 - by Julianna Photopoulos 
A gene involved in the brain's reward system has been found to affect people's ability to quit smoking, according to a new study...
08 June 2015 - by Dr Julia Hill 
Scientists have discovered that changes to DNA which occur during a person’s lifetime can be passed on to future generations...

HAVE YOUR SAY
Be the first to have your say.

You need to or  to add comments.

By posting a comment you agree to abide by the BioNews terms and conditions


- click here to enquire about using this story.

Published by the Progress Educational Trust

CROSSING FRONTIERS

Public Conference
London
8 December 2017

Speakers include

Professor Azim Surani

Professor Magdalena Zernicka-Goetz

Professor Robin Lovell-Badge

Sally Cheshire

Professor Guido Pennings

Katherine Littler

Professor Allan Pacey

Dr Sue Avery

Professor Richard Anderson

Dr Elizabeth Garner

Dr Andy Greenfield

Dr Anna Smajdor

Dr Henry Malter

Vivienne Parry

Dr Helen O'Neill

Dr César Palacios-González

Philippa Taylor

Fiona Fox

Sarah Norcross

Sandy Starr


BOOK HERE

Good Fundraising Code

Become a Friend of PET HERE and give the Progress Educational Trust a regular donation