As of 2013, the American Medical Association has officially classified obesity as a disease. Affecting 36% American adults each year, its rising numbers have caused worry for health professionals warning against side effects such as diabetes, heart disease, and many other fatal health issues. When discussing obesity, it is easy to blame the individual who has it for having a poor diet, being lazy, or just not caring. But in all reality, studies like this and many others have shown that obesity has been found to be genetic in the terms that it affects ones metabolism. Recently though, a study has been published that has shown evidence that not only is obesity genetic, it also affects the grown of fetuses during pregnancy.
The study is titled Maternal Pre-Pregnancy Body Mass Index and Newborn Telomere Length and it was published just this month in BMC Medicine. Its focus was on how an expecting mothers BMI, a number determining what a healthy weight for a should be based on their height, correlated to the length of their baby’s telomeres. A telomere, according to T.A. Sciences, are tips on the end of our DNA (pictured below) that keep the DNA structure stable. As explained early in the study, the reason the length of a telomere is important is because it allows scientists to see what chances a person has of developing diseases associated with age. When a person’s telomere is shorter, the chance of them developing diseases earlier than expected in life increases. In terms of this study, researchers wanted to see if there was a mechanism relating a mother’s weight before and during pregnancy to the length of her child’s telomeres, and eventually affect their overall health.
For this study, the null hypothesis was that a mother’s weight would not affect her child’s telomeres, and the alternative hypothesis was that a mother’s weight would affect her child’s telomeres. Researchers collected data on the 768 expecting mothers regarding their height, and weight before and after pregnancy, and were then sorted into groups: normal, overweight and obese. Later, when the women went into delivery, their weights were taken again and so was umbilical cord blood. With this blood, DNA samples were taken and assessed for telomere length. Once this analysis was finished, the results found followed the studies alternative hypothesis; The cord blood of mother’s in the normal weight range had children whose telomeres were shorter than those of children with overweight or obese mothers.
Despite this logical correlational, one potential issue I see in this blog are all the other confounding variables that would be needed to be taken into account such as the mother’s family health history, and the father’s BMI and family health history. Also, the BMI measurement has long been debated as not being an effective way to calculate obesity, but obesity is something that is obvious to see so the accuracy of the BMI would not skew any results. In the study a third variable that was measured was level of smoking, but I think it also would have been interesting to have seen how the level of the mother’s exercise and eating affected the results, but that type of self documented data is not always true and could have been falsely recorded by the mother.
In terms of the results, there is no possible way reverse causation could have been a mechanism since the telomeres of an unborn child or un-conceived egg cannot affect on the weight of the mother. But, there is also the chance that the results are just a false positive since it was a smaller scale study that had lots of third variables that should have been taken into account.
While I think third variables pertaining to the mother’s lifestyle would need to be assessed, I do find these results fully believable. I hope that further research is made on the topic of weight and infant health for this topic is one that is very relevant in todays society.
New York Times: http://www.nytimes.com/2013/06/19/business/ama-recognizes-obesity-as-a-disease.html?_r=0
AMA on obesity: http://www.ama-assn.org/ama/pub/physician-resources/public-health/promoting-healthy-lifestyles/obesity.page
CDC on obesity:http://www.cdc.gov/obesity/data/adult.html
Science Direct: http://www.sciencedirect.com/science/article/pii/S1521690X01901538
Study Link: https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-016-0689-0
CDC on BMI: https://www.cdc.gov/healthyweight/assessing/bmi/
T.A. Sciences on telomeres and photo: https://www.tasciences.com/what-is-a-telomere/