Fit dads influence the mental health of their sons BEFORE they’re conceived

Now there's another reason to tell your man to get off the couch.

At this stage, we all know exercise is good for you and that physical activity helps to keep your heart heathy, your mind sharp, and your bones strong. Exercise has also been shown to be as effective as anti-depressants for some mood disorders. New research from scientists at Australia's Florey Institute has shown that increasing a dad’s exercise levels might positively impact the mental health of his unborn sons - giving hopeful dads even more reason to lace up the running shoes before sliding between the sheets. The team has identified molecular pathways that could transmit beneficial exercise-induced signals from fathers down to their male offspring, according to Professor Anthony Hannan of the Florey Institute of Neuroscience and Mental Health:

"Epigenetics is an emerging area of interest in biological research. It is the bridge between 'nurture' and 'nature', providing the signals that switch certain genes on or off in response to our environment."

The researchers gave male mice a four-week exercise program to follow. Unlike some of their human counterparts, these mice absolutely love to run, making their fitness regime no burden at all. A second group of non-running 'Homer Simpson' mice sat around in their cages without access to the exercise wheels. The fit fathers (and Homers) were then mated with non-running female mice, and the offspring mice were put through a range of behavioural and anxiety assessments. Professor Hannan explains:

"Our most striking findings was that the male offspring of running mice were better at suppressing bad memories as juveniles, and had lower anxiety levels as adults than male offspring of sedentary fathers. In contrast, female offspring of fit fathers showed no differences to the female offspring of sedentary fathers."

In an exciting discovery, the group has identified an emerging type of epigenetic signal in the fit fathers' sperm that may be responsible for the improved mental health of the sons. These factors are called small non-coding RNAs, which are produced by non-coding (known as 'junk') sections of our DNA, and were previously thought to have no useful function. The researchers are learning exactly how these signals get into the sperm, and their effect on genes which direct the offspring’s brain development and function.

"This work is difficult to perform in humans as it’s hard to separate the environment that the children were reared in from the genetic component inherited from their parents, except in adoption studies. The fact that we have identified a molecular pathway that could allow the 'inherited' benefits of exercise from your father really shows the power of doing these studies in closely related animal models."

Professor Hannan says that, at the moment, health advice around conception mainly focuses on healthy lifestyle and diet in women but this new work emphasises the need to also optimise the dad's environment and lifestyle:

"Not only will more physical activity improve your own health, it could have a positive impact on the health of your offspring."