As scientists continue to look for clues as to how dementia can be prevented and cured, they've found that the bodybuilding supplement beta-hydroxy beta-methylbutyrate (or HMB) protects against cognitive decline in mice.

Researchers from Rush University and the Simmaron Research Institute in the US found that the muscle-building supplement helped keep learning and memory brain regions healthy, as well as reducing plaque build up in mouse brains engineered to echo the symptoms of the human condition Alzheimer's disease.

Plaque build up in the brain is typical of people with Alzheimer's. While it's not yet certain what causes the disease, these plaques – aggregations of amyloid beta and tau proteins – are thought to be key to the failing of neurons.

While this study involved mice, the team is hopeful that HMB could be repurposed to fight dementia conditions such as Alzheimer's in people. The good news is that HMB is already considered safe to use for muscle gain, even over longer timescales.

"This may be one of the safest and the easiest approaches to halt disease progression and protect memory in Alzheimer's disease patients," says neuroscientist Kalipada Pahan from Rush University.

Close analysis revealed that the HMB supplement was interacting with peroxisome proliferator-activated receptor alpha (PPARα), a signal receiver in the brain that helps metabolize fatty acids – hence its success in building up muscle.

Previous studies had identified the importance of a family of proteins known as neurotrophic factors in keeping neurons functioning correctly. Levels of these proteins are lower in people with Alzheimer's, but HMB seemed to replenish them.

"Our study found that after oral consumption, HMB enters into the brain to increase these beneficial proteins, restore neuronal connections and improve memory and learning in mice with Alzheimer's-like pathology, such as plaques and tangles," says Pahan.

In short, it's a double-win for HMB – it maintains the sort of neural performance that Alzheimer's can take away, while also targeting some of the physical manifestations that are associated with the progression of the disease.

Further research is going to be required to figure out the exact mechanisms that HMB is using to achieve its effects – and we'll need to see the same effects in humans of course. However, it's another promising step forward.

While scientists continue to make progress in understanding more about how Alzheimer's works and how we might be able to fight it, it remains a disease with no cure – and one that affects millions of elderly people across the world.

"Understanding how the disease works is important to developing effective drugs to protect the brain and stop the progression of Alzheimer's disease," says Pahan.

The research has been published in Cell Reports.