Page URL:

Smoking and obesity linked to ageing genetic material

16 June 2005
By BioNews
Appeared in BioNews 313

Obesity and smoking can result in changes to genetic material indicative of cellular aging, according to a new UK study. The research, carried out at St Thomas' Hospital in London, shows that women who are obese, or who are heavy smokers have shorter telomeres - protective caps on the ends of a cell's chromosome. The team, who published their findings in the Lancet, say the ageing effect may explain why such women are at increased risk of age-related health problems.      

The researchers collected health information and blood samples from 1,122 women aged between 18 and 76 years. Around 11 per cent were clinically obese, and about 18 per cent were active smokers. They looked at the ends of the chromosomes (bundles of genetic material found in almost every body cell) present in white blood cells. In particular, they measured the length of the telomeres of the chromosomes.

It has long been known that telomeres act as a kind of cellular clock, marking the number of times a cell has replicated its genetic material. Each time a cell divides to make two new cells, its telomeres get shorter, until eventually it stops multiplying altogether. So the length of a cell's telomeres, measured in base-pairs (chemical 'letters') of DNA, reflects the age of the parent cell. A study published in 2003 suggested that people with shorter telomeres may die earlier than those with longer telomeres.

In the latest study, the researchers found that the telomeres of obese women in the study were nine years 'older' than slim women of the same age, while those of heavy smokers were seven years older. Overall, the telomeres of the women in the study shrank by about 27 DNA base-pairs per year, but the telomeres of those who had smoked for over forty years were around 200 base-pairs shorter than non-smokers. Being overweight had an even greater effect - the telomeres of obese women were, on average, 240 base-pairs shorter than those of slim women.

The authors stress that they have only looked at white blood cells so far, and obesity and smoking may not have the same effect on other body tissues. They now plan to look at the effect of other lifestyle factors on telomere length, such as exercise, diet and occupation.

Cigarettes age your DNA
Nature News |  13 June 2005
Obesity may accelerate the ageing process
New Scientist |  14 June 2005
Smoking and obesity 'age people'
BBC News Online |  14 June 2005
8 September 2008 - by Ailsa Stevens 
Men who carry a particular gene variant may be up to three times more likely to live to the age of 100, according to a study published in the journal Proceedings of the National Academy of Sciences. Although other gene variants have been previously linked to longevity...
2 December 2004 - by BioNews 
Stress can speed up the aging process, according to a new US study. Scientists based at the University of California have found that cells taken from women who experience high levels of stress appear years older than their actual biological age. The research, published in the Proceedings of the National...
3 February 2003 - by BioNews 
The length of your life could be related to the length of your telomeres - the segments of DNA that make up the ends of chromosomes. A new study suggests that people with shorter telomeres may die earlier than those with longer telomeres, either from an infectious disease or a heart...
to add a Comment.

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

Syndicate this story - click here to enquire about using this story.