Blame Your Great-Grandparents for Your Obesity
What your great grandmother ate is what you are, according to a new study.
New research reveals that environmental factors in the womb can influence not only the mother's own offspring but also the grand offspring in terms of risk of metabolic disorders and liver disease.
Scientists found that malnourished pregnant that experienced a 50 percent caloric restriction during the last week of pregnancy had offspring of growth restriction and low birth weight. However, these offspring were also more likely to develop obesity and diabetes during old age.
Researchers were surprised to also discover this "domino effect" in the offspring of growth-restricted males. The study revealed that the offspring of male mice that developed in the wombs of malnourished mothers were more likely to develop metabolic abnormalities.
To understand how the mechanism behind these effects, lead researcher Dr. Josep Jiménez-Chillarón, of the Hospital Sant Joan de Déu in Spain, and his colleagues examined patterns of gene expression in mice.
Jiménez-Chillarón and his team found that in utero malnutrition of males influenced the expression of the gene LXR, which maintains fat and cholesterol metabolism in his offspring's livers.
Researchers explain that this is partly caused by an epigenetic change called DNA methylation, which influences gene activity without changing the DNA's underlying sequence. The same pattern of methylation is found in the sperm of the male mice that experienced in malnutrition in the womb.
"This may contribute, in part, to the transmission of diabetes risk from parents to offspring," Jiménez-Chillarón said in a news release.
Researchers said that latest findings suggest that in utero malnutrition causes epigenetic changes in reproductive cells that are later passed on to cells of future generations.
"Current dogma proposes that the vast majority of epigenetic modifications in the sperm and eggs are erased precisely to avoid transmission of environmentally derived changes. But our data suggest that a few environmentally induced epigenetic modifications may be passed and stably maintained in the next generation," said Jiménez-Chillarón.
"Our view is that we inherit some predisposition, but it is our own lifestyle that will determine whether inherited risk will truly translate into disease. Hence, a healthy lifestyle is the best way to prevent any potentially inherited or newly acquired obesity or diabetes predisposition," he concluded.
The findings are published in the Cell Press journal Cell Metabolism.