Turning Genetics On Its Head: Grandma Smokes While Pregnant With Mom = Asthmatic Grandkids?

Smoking and drinking during pregnancy
Smoking and drinking during pregnancy (Photo credit: Wikipedia)

Most of us are familiar with the basic premise of genetics. Your dad had a disease, and passed it down to you.  Nothing you can do about it.

The number of hopeless genetic-based diseases is constantly rising.  When a patient hears “it’s genetic” they often mistake that for “it’s hopeless and there is nothing anyone can do.”  Taking those patients back down the road of diet and lifestyle change is doubly-difficult, despite showing them research that their conditions can be improved.

Now comes a strange little study that points to another possibility.  The study found that smoking by grandmothers led to a doubling of the risk of asthma in her grandchildren.  Here’s the catch.  It wasn’t second-hand smoke that caused the increase.  It was grandma smoking during her time being pregnant with mom.

Yikes!  Holy guilt monster, batman!  Now if we can show this applies to weight, parents unable to keep weight off can now blame not only their parents and their grandparents.

It’s possible to just wave this away as being indicative of other smoking habits, but it raises a very important question: do we create our genetic inheritance?  Is it possible to positively and negatively affect the genes of our children and grandchildren?

Of course it’s possible.  Look at the poor guys who get to move around radioactive material, and the even more unfortunate marsh creatures who live around that material.  But it’s a big step to go from radiation to lifestyle choices.

If we can upregulate or down regulate genetic information based on lifestyle choices, it brings up the biochemical reality of an inheritance from our behaviors.  Family karma if you will, with generations of bad lifestyle choices continually upregulating disease processes.

So parents unable to keep weight off can now blame not only their parents and their grandparents.

The opposite is also true.  I was talking with a patient yesterday about why, despite living a healthy life, he had become ill.  Now he can point to his wish to provide his children with a better genetic beginning, as he downregulates the diseases in his own genetic material.

What about all those high-powered parents out there?  Time to get a genetic baseline and to take those supplements and make those choices to make junior smarter and healthier?

We don’t know the extent of how much we can alter genetic expression, but it is clear that something “being genetic” as a static diagnosis will need to go the way of the “it’s the will of the Gods.”  Neither explains the complexity of what is going on in the human genome.

Chest. 2005 Apr;127(4):1232-41.

Maternal and grandmaternal smoking patterns are associated with early childhood asthma.


Department of Preventive Medicine, USC Keck School of Medicine, 1540 Alcazar St, CHP 236, Los Angeles, CA 90033, USA.



To investigate the associations of maternal and grandmaternal smoking before, during, and after pregnancy with childhood asthma.


We conducted a case-control study nested within the Children’s Health Study in southern California. The case patients consisted of 338 children with asthma that had been diagnosed in the first 5 years of life, and 570 control subjects were countermatched on in utero exposure to maternal smoking within grade, sex, and community of residence.


Detailed maternal and household smoking histories and other asthma risk factor information was obtained by telephone interview.


The participation rates were 72.3% and 82.5%, respectively, for control subjects and case patients. In utero exposure to maternal smoking was associated with increased risk for asthma diagnosed in the first 5 years of life (odds ratio [OR], 1.5; 95% confidence interval [CI], 1.0 to 2.3), and for persistent asthma (OR, 1.5; 95% CI, 1.0 to 2.3). The associations did not differ in children with early transient asthma compared to those with early persistent asthma. Relative to never-smokers, children whose mothers smoked throughout the pregnancy had an elevated risk of asthma in the first 5 years of life (OR, 1.6; 95% CI, 1.0 to 2.6). Children of mothers who quit smoking prior to the pregnancy showed no increased risk (OR, 0.9; 95% CI, 0.5 to 1.5). We were unable to assess the association of smoking cessation during pregnancy because very few mothers were reported to have done so (15%). Asthma risk did not increase in a monotonic pattern with smoking intensity during pregnancy. Postnatal secondhand smoke exposure was not independently associated with asthma. Grandmaternal smoking during the mother’s fetal period was associated with increased asthma risk in her grandchildren (OR, 2.1; 95% CI, 1.4 to 3.2).


Maternal and grandmaternal smoking during pregnancy may increase the risk of childhood asthma.

PMID: 15821200

2 Replies to “Turning Genetics On Its Head: Grandma Smokes While Pregnant With Mom = Asthmatic Grandkids?”

  1. Well, my grandmothers did not smoke. My mom is skinny as a rail and always has been. My dad is thin for a tall man. My troubles came from somewhere down the line, I think.

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