How your grandmother's smoking habit could give YOU asthma
The risk holds even if your mother didn't take up the habit, say expertsNicotine can leave a 'mark' on our DNA, making future generations more susceptible to respiratory conditions such as asthma
16:33 GMT, 5 March 2013
17:19 GMT, 5 March 2013
People whose grandmothers smoked during pregnancy are more likely yo suffer from asthma – regardless of whether their mother smoked or not
Having a grandmother who smoked can increase your risk of suffering from asthma – even if your mother didn't take up the habit.
Researchers say the discovery shows how the chemicals and environmental factors we are exposed to today could determine the health of family members for generations to come.
Writing in the Review of Obstetrics & Gynecology, the scientists cited a rat study they say has major ramifications for human health.
They found that pregnant rats given nicotine produced
These rats, in turn, went on to produce their own asthmatic children, despite
the fact they had not been directly exposed to nicotine.
The researchers, from the Los Angeles Biomedical Research Institute, say the findings show that nictotine can leave a 'mark' on the genome (our complete set of DNA), making future generations more susceptible to respiratory conditions such as asthma.
In other words, the cause
of the grandchild's asthma was a genetic change caused by an environmental factor – in this case, smoking.
As a result, they concluded that environmental factors experienced during
pregnancy – such as smoking – will not just affect the child in the womb, but those further down the line.
The findings back up previous research which has also indicated a link between grandmaternal health and a child.
Scientists at the University of Southern California found that grandmaternal smoking during pregnancy
increases the risk of asthma in grandchildren – regardless of whether
the mother smoked or not.
The asthma discovery shows how the chemicals we are exposed to today could determine the health of family members for generations to come
What is worrying, say the researchers, is that global asthma rates are rising.
World-wide, around 250million women smoke daily. Twelve percent of women in the U.S. continue to smoke during pregnancy, resulting in the birth of at least 400,000 smoke-exposed infants per year.
Research published last month in the Annals of Oncology found that lung cancer deaths in British women outnumber those from breast cancer and will continue rising for the rest of the decade.
The figures are blamed on the rise of oung women starting smoking in the late 1960s and 1970s, possibly due to changing socio-cultural attitudes at that time
Dr Virender Rehan, one of the paper's authors, said: 'Asthma is the most common chronic disease of childhood, resulting in a significant impact on the lives of children.
'While many factors contribute to asthma, smoking during pregnancy is a well-established one and one that can be avoided.
'Eliminating smoking during pregnancy would significantly reduce the prevalence of childhood asthma for this generation and for future generations.'