Your parents’ sex cells can cause you to become diabetic and obese because the two health conditions can be epigenetically inherited via sex cells, says a new study published in Nature Genetics.
The past few decades have witnessed a dramatic rise in non-communicable diseases like diabetes and obesity. The situation has even reached epidemic proportions. Therefore, researchers are forever attempting to investigate the underlying mechanisms of the conditions to lower their rate.
With a similar goal in mind, scientists from the Technical University of Munich, the German Center for Diabetes Research (DZD), and the German Research Centre for Environmental Health have studied the “epigenetic germline inheritance of diet induced obesity and insulin resistance” (the title of their paper).
Epigenetics refers to modifications in gene expression that are passed on from parent to offspring; it does not involve changes in the DNA sequence itself. The new findings show that such inheritable changes can be transferred via both the female egg (the oocyte), and the sperm.
The researchers reached to their conclusions after observing obese mice which were also suffering from type 2 diabetes as a result of a high-fat diet. The offspring of these mice came into existence through in-vitro fertilisation from isolated oocytes and sperm — this implies that changes characterising the offspring will have only come from these specific cells. As a further precaution, the baby mice were carried by surrogate mothers to rule out any other factor that could affect them, such as the real mother’s influence, and parental behaviour.
Lead author, professor Johannes Beckers, explains that while both oocytes and sperms pass on epigenetic information, the female offspring was more vulnerable to severe obesity and the male to changed blood glucose level. Furthermore, the data indicate that the change in metabolism was influenced by the mother’s contribution more than the father’s, as is the case in humans.
Another author of the study, professor Martin Hrabě de Angelis, adds that the high prevalence of diabetes might have been compounded by the epigenetic inheritance of metabolic disorders caused by unhealthy eating habits, specially that gene mutation (changes in the DNA sequences) cannot adequately explain the rapid rise.
The situation is not all grim and gloomy, though. The scientists say that since epigenetic inheritance is reversible (unlike genetic inheritance), diabetes and obesity can now hopefully be tackled in new ways.