Obesity among males has a lasting legacy on their offspring, a study shows.
Scientists at Sydney's Victor Chang Institute and the Garvan Institute of Medical Research have discovered that male mice who were obese when they conceived put their children and grandchildren at significant risk of developing metabolic disease - long before they were even born.
The study's lead author, Associate Professor Catherine Suter, says they've found powerful evidence in a mouse model that dad's nutrition and metabolic health can influence his sons, and even grandsons.
The researchers looked at the effect of dad's obesity across three generations.
First offspring appeared in good metabolic health, but when they consumed a high-fat, high-sugar, junk food diet, all three sons reacted dramatically.
Within just a few weeks they developed fatty liver disease and pre-diabetic symptoms, such as elevated glucose and insulin in the bloodstream.
The grandsons of the obese mice were also predisposed to metabolic disorders, just as their fathers were.
This predisposition was transmitted to the grandsons even if their fathers ate well and were metabolically well at the time of conception.
Prof Suter says they were shocked by the results.
"The grandchildren are at significant risk of getting very sick if they eat a 'junk food diet' - even when their father eats well and is healthy," she said.
"The effects of the diet on offspring are dramatic, even when they eat poorly for a just for a short time, all because their grandfather was obese."
In a more positive outcome, researchers observed that the metabolic health of the great-grandsons improved significantly.
What this shows, says Professor Mark Febbraio from Garvan, is that it's possible to break the cycle of metabolic disease.
"It's crucial to note that this predisposition isn't genetic. Instead, it's acquired. That means the damage can be undone and is ultimately reversible," he said.
Investigations are now underway to understand how sperm could transmit the metabolic effects from generation to generation.
The study has been published in journal Molecular
Metabolism.
