Men reassured research on ageing mice not applicable

University of Otago anatomy Associate Professor Dr Mike Garratt holds one of the mice he has been...
University of Otago anatomy Associate Professor Dr Mike Garratt holds one of the mice he has been researching. PHOTO: LINDA ROBERTSON
New research may show sensory cues from female mice can affect ageing and health in male mice, but scientists are warning men not to start blaming their female partners for their greying hair and wrinkles.

University of Otago anatomy Associate Professor and study lead author Dr Mike Garratt said the results would not necessarily translate directly to humans.

For the study, researchers from Otago and the University of New South Wales tested if exposure to female odours influenced mortality and reproductive ageing in male mice.

Male mice were housed in four environments — alone; with two females; alone but with exposure to scents from two absent females; or housed with two females along with the scent of two absent females.

The researchers found males exposed to female olfactory cues, or chemical smell signals, from middle to old age had reduced fertility later in life.

Males exposed to female odours in conjunction with mating also showed a speeding up of the ageing process and an increased mortality rate.

Dr Garratt said he was surprised by the results.

"We set out to test whether odours could do this. The effects it had on male mortality were really quite striking.

"Half of the animals in the group who were exposed to female odours died over the course of the experiment, whereas the ones who weren’t exposed to the odours had very few deaths.

"That was a really surprising result.

"It builds on some of our more general research which shows sensory cues can cause changes to your body that are sufficient to influence how you age."

It was not known why these effects occurred, but Dr Garratt said the results highlighted how sensory perception of mates might be an important driver of life-history trade-offs in mammals.

He said smells alone were not likely to affect humans in the same way.

"Women making men older — I’ve definitely been trying to steer away from that narrative.

"In mice, smells are so important that just a pheromone in a mouse can drive these massive changes in behaviour and ultimately ageing.

"Whereas, in humans, we use lots of different cues to try and make decisions about who we’re going to have a relationship with.

"So it’s unlikely that a single cue like smell in humans is going to have the same effect.

"There are cues from our environment like smell, sight and hearing, but also we’re building on other cognitive knowledge that we’ve built up from the past.

"It’s a much more complicated situation in humans than it is in mice."