The study, conducted by Professor Diana Anderson from the University of Bradford's Division of Medical Sciences, found a strong association between DNA changes in the sperm of fathers who smoke and DNA changes in their newborn babies.
According to the researchers, nearly all cancers in humans are caused primarily by genetic changes. Their findings indicate that children may be at increased risk of developing genetic diseases if they inherit these genetic changes.
Although studies in mice have indicated that offspring may inherit DNA changes as a result of paternal exposure to smoking, this is the first study to examine this effect of smoking in humans.
In humans it is extremely difficult for researchers to determine if heritable genetic changes are caused by the mother's or the father's exposure to cigarette smoke. Another challenge is to determine whether these changes are influenced by other factors, such as the environment, diet, or alcohol.
The team enrolled families from Bradford in the north of England as well as from Heraklion on the Greek island of Crete. Questionnaires provided the researchers with information about the lifestyle, occupational, and environmental exposures of these families, all of which can influence DNA.
The researchers used two sensitive biomarkers in order to measure single and double strand breaks in the DNA of the paternal blood and semen around the time of conception, and in the maternal and umbilical cord blood at birth.
In order to help distinguish the role of the different exposures before and after conception, which could result in genetic alterations in the developing embryo, the researchers used a combined analysis of exposures and DNA biomarkers.
Professor Anderson, explained:
"Whilst our cohort size was small, the biomarkers were very sensitive, we were struck by the correlation between paternal smoking around the time of conception and DNA damage found in the newborns.
To be clear, this study does not show a direct causal link to any disease, but it's evident that the lifestyle of men before they try to conceive can directly affect the genetic information of their children.
Anti-smoking campaigns are usually aimed at pregnant women, but couples planning their families - and public health policy-makers - need to know that the father must stop smoking before conception to avoid risking the health of the baby."
Co-author of the study, Dr Julian Laubenthal, University of Bradford, said: "It's also important to know that a fertile sperm cell takes around three months to develop, so men should stop smoking well in advance of trying to conceive."
The study was funded by the European Union.