Exercise benefits to the brain 'may be passed on'

Physical and mental exercise has been found to be beneficial for our brains, but scientists have now found it could also improve the learning ability of our children.

In a mouse study, researchers found the benefits gained from these activities were passed on to their offspring, despite not altering their DNA.

Further research is needed to see if this replicates in humans.

The German study is being published in the journal Cell Reports.

Exercise is recommended to keep the mind sharp in the over-50s and doing puzzles and brain training exercises has been found to delay the onset of dementia and reduce the risk of diseases such as Alzheimer's.

Researchers from the German Centre for Neurodegenerative Diseases (DZNE) found that when they exposed mice to a stimulating environment in which they also had plenty of exercise, their offspring which they had later also benefitted.

The younger mice achieved better results in tests that evaluated their learning ability than the control group.

They also had improved synaptic plasticity - which is a measure of how well nerve cells communicate with each other and the cellular basis for learning.

They found this in the hippocampus, the area of the brain that is important for learning.

This phenomenon is known as epigenetic inheritance.

What is epigenetics?

• Epigenetics is a growing field trying to understand how the environment interacts with genes.

• Previously it was believed that acquired skills don't modify the DNA sequence so therefore can't be passed on to children.

• But in recent years scientists have found that in some circumstances lifestyle factors such as stress and trauma in parents can affect the next generation.

• For example, a poor diet increases the risk of disease in ourselves but also raises the risk in our children.

• This phenomenon is known as "epigenetic" inheritance, as it is not associated with changes in DNA sequence.

They found the benefits were conveyed through the RNA molecules that are contained in sperm, along with paternal DNA.

"Presumably, they modify brain development in a very subtle manner improving the connection of neurons. This results in a cognitive advantage for the offspring," said Prof André Fischer from DZNE.

The researchers say that whether their findings are translatable to people needs to be determined.

Prof Marcus Pembrey, from Great Ormond Street Institute of Child Health, said the research was an "important step" in unravelling "what, if anything, contributes to an individual's intelligence beyond genetic inheritance and learning after birth".

He added: "If this system of the offspring inheriting a 'head start' applies to humans, it might help to explain the so-called Flynn effect, where the population IQ in industrial societies has risen every decade for the last century."

Prof Simon Fishel, of the private Care Fertility group, said it was a "fascinating study" providing "further increasing evidence of how we conduct our lives before we conceive our children may have consequences for our offspring".

He said it "opens up further the enthralling study of a 'transgenerational inheritance' and added: "However, there is much work to do to understand if this study can not only be replicated in mice, but other mammalian species too, and ultimately in humans."