In Germany alone, almost a quarter of the population aged 18 and over regularly smokes cigarettes. The hardest consequences of smoking, such as lung cancer and death, have long been known. What is new, however, is the realization that tobacco consumption could still influence the physical development of one’s own great-grandchildren decades later.
Smoking and the consequences: mysterious connection found
A recent study published in Scientific Reports on January 21, 2022 hints at the unusual association. According to the study, the great-granddaughters of men who smoked in their pre-adolescent phase are more likely to have excess body fat as young women.
The researchers involved explain that this is one of “the first human demonstrations of intergenerational effects of environmental pollution over four generations,” as ScienceAlert reports.
“If these associations are confirmed by other data, this will be one of the first human investigations with data suitable for (…) dissecting the origins of potentially important intergenerational relationships.”
Jean Golding, Epidemiologist at Bristol University (UK)
First evidence of the unknown consequences of smoking
In 2014, lead author, epidemiologist Jean Golding, and a team analyzed data from the Avon Longitudinal Study of Parents and Children, dubbed “Children of the ’90s.” This is an observational study of pregnant women and their families that began in the early 1990s and was originally conducted by Golding.
The analysis at the time revealed that the sons of fathers who started smoking before the age of 11 were very likely to have a higher body mass index (BMI) when they were young. Including a larger average hip size and higher total body fat percentage.
As part of the current study, Golding and his colleagues delved even deeper into the “Children of the 90s” data set. It was shown that the phenomenon extends significantly further across the generations. Among other things, from a grandfather to his granddaughter and from a great-grandfather to his great-granddaughter.
“We now show that granddaughters, but not grandchildren, are born at two ages [17 und 24 Jahre] Signs of excess fat mass show when the paternal grandfather started smoking before puberty [jünger als 13]compared to later in childhood (13-16 years).”
Golding et al.
If, on the other hand, it was the maternal grandfathers, the same observation applied to their great-granddaughters, but not great-grandchildren.
Further investigations needed
According to Golding, the fact that smoking can be associated with such consequences also allows a different perspective on the circumstances that make children obese. So it doesn’t have to be related to their current diet and physical activity. Rather, the lifestyle of their ancestors could play a role.
However, much more research is needed on the phenomenon to understand what is happening. One should also be aware of the limitations of one’s own analysis. A large amount of data is missing, such as the knowledge of the participants about their parents’ and grandparents’ childhood and the circumstances surrounding it.
Sources: ScienceAlert, Scientific Reports: “Human transgenerational observations of regular smoking before puberty on fat mass in grandchildren and great-grandchildren“