What father eats affects his offspring- study
Researchers, who specifically looked at the effects of paternal diet in their study, have discovered that a father's lifestyle can be passed down to next generation because it "reprogrammes" his genes.
The novel mice study, carried out by researchers at the University of Massachusetts Medical School and the University of Texas at Austin, shows that paternal diet influences lipid metabolising genes of his children.
The new findings reported in the December 23rd issue of Cell, a Cell Press publication, highlight the hereditary effects of a process called "epigenetics", which is how our environment and lifestyle can permanently alter our genes as we grow up.
These altered genes can then be passed on from one generation to the next.
For their study, Dr Oliver Rando of University of Massachusetts Medical School and his team fed different diets to two groups of male mice, with the first feeding on a standard diet and the second on a low-protein diet.
Female mice were all fed the same, standard diet, in order to control for maternal influences.
After observing the activity of genes in mice whose fathers were fed a low-protein diet as they were growing up, Rando and colleagues found that hundreds of genes changed in the offspring of those protein-starved males.
The offspring of the mice of low-protein diet group exhibited a significant boost in the genes responsible for lipid and cholesterol synthesis in comparison to those of the standard diet group, indicating an increased risk of heart disease.
"Knowing what your parents were doing before you were conceived is turning out to be important in determining what disease risk factors you may be carrying," said Rando, according to Telegraph.co.uk.
"A major and underappreciated aspect of what is transmitted from parent to child is ancestral environment. Our findings suggest there are many ways that parents can 'tell' their children things.
"We often look at a patient's behaviour and their genes to assess risk. If the patient smokes, they are going to be at an increased risk for cancer. If the family has a long history of heart disease, they might carry a gene that makes them more susceptible to heart disease.
"But we're more than just our genes and our behaviour. Knowing what environmental factors your parents experienced is also important."
Study rules out social and economic factors
Epigenomic profiling of the offspring livers showed numerous differences depending on paternal diet, including chemical modification of a sequence of DNA that affects cholesterol and fat synthesis in the liver.
"Our study begins to rule out the possibility that social and economic factors, or differences in the DNA sequence, may be contributing to what we're seeing,” Rando added. "It strongly implicates epigenetic inheritance as a contributing factor to changes in gene function."
Focus is now on what the offspring exhibit
The authors of the study are still unsure why these genes are being reprogrammed or how, precisely, that information is being passed down to the next generation.
"It's consistent with the idea that when parents go hungry, it's best for offspring to hoard calories, however, it's not clear if these changes are advantageous in the context of a low-protein diet," they wrote.
Rando and colleagues are now curious to see what happens in the next generation of mice. "The human studies suggest that it is grandchildren who are most affected by their grandparents' exposure histories," he said.