Environmental factors and parents’ health before conception have more influence on a child’s future than previously thought, a paper published last week in Science by researchers from the University of Adelaide has found.
The authors conclude that there is now overwhelming evidence that sperm and eggs carry more than just genes - they are also coded with genetic memories that can affect the health of an embryo.
This means that parents' bad habits, such as poor diet or drinking too much alcohol, could be passed on to their children, even if they are healthy during pregnancy or shortly before conceiving.
"Many things we do in the lead up to conceiving is having an impact on the future development of the child - from the age of the parents, to poor diet, obesity, smoking and many other factors, all of which influence environmental signals transmitted into the embryo," Sarah Robertson, an author of the paper and Director of the University of Adelaide’s Robinson Research Institute, said in a press release.
"People used to think that it didn't matter, because a child represented a new beginning, with a fresh start. The reality is, we can now say with great certainty that the child doesn't quite start from scratch - they already carry over a legacy of factors from their parents' experiences that can shape development in the fetus and after birth. Depending on the situation, we can give our children a burden before they've even started life."
Over the past decade, scientists have been investigating the way that these memories and habits can be passed on to offspring, through a process known as epigenetics. This refers to the ability of environmental factors to turn the expression of genes on or off, without actually changing the DNA or genetic code.
Now, the paper concludes, there is sufficient peer-reviewed research to claim that a baby’s health begins with parents long before conception.
Although, she stresses to Brad Crouch, from The Advertiser, genes are still the primary blueprint for a new child. “But this is at another level, it is the decoration of the gene, the icing on the cake if you like, a gift to offspring that gives them another layer of information about survival,” said Robertson.