Obese dads may put their kids at risk of disease

A father's obesity may influence his children's health and potentially raise their risk for diseases like cancer, according to new research.

The study by researchers from Duke University Medical Center is the first in humans to show that paternal obesity may alter a genetic mechanism in the next generation, suggesting that a father's lifestyle factors may be transmitted to his children.

"Understanding the risks of the current Western lifestyle on future generations is important," said molecular biologist Adelheid Soubry, the study's lead author.

"The aim of this study was to determine potential associations between obesity in parents prior to conception and epigenetic profiles in offspring, particularly at certain gene regulatory regions," Soubry said in a statement.

The Duke team sought to determine associations between obesity in parents and changes in DNA methylation at the insulin-like growth factor 2 (IGF2) gene among offspring.
DNA methylation regulates the activity of certain genes, which can reflect a higher risk for some diseases.

Decreased DNA methylation at the IGF2 gene has been associated with an increased risk of developing certain cancers, including colorectal and ovarian cancers.

"Our genes are able to adapt to our environment. However, we adjust in a way that may be problematic later," said Cathrine Hoyo, the study's senior author.

"It is not a change in the sequence of the DNA itself, but how genes are expressed. Some genes may get 'shut off' as a result of environmental trauma," Hoyo said.

To gather data on newborn health outcomes, the researchers followed families enrolled in the Newborn Epigenetics Study (NEST), a research programme developed by Hoyo to test the influence of environmental exposures on genetic profiles in newborns.

Researchers gathered information about the mothers and fathers using questionnaires and medical records. They then examined DNA from the umbilical cords of 79 newborns to determine potential associations between the offspring's DNA methylation patterns and parental obesity before conception.

DNA methylation at the IGF2 gene in the offspring of obese fathers was significantly lower than in the children of fathers who were not obese.

This suggests that paternal obesity may be associated with an increased risk of children developing certain cancers.

"This study is an important start in looking at the effects of environmental exposure on children, not only through the mother but also through the father," said Soubry.

The study was published in the journal BMC Medicine.