Longevity Briefs: Could Light Therapy Slow Cardiovascular Ageing?

Longevity briefs provides a short summary of novel research in biology, medicine, or biotechnology that caught the attention of our researchers in Oxford, due to its potential to improve our health, wellbeing, and longevity.

Why is this research important: Photobiomodulation or PBM (more colloquially known as light therapy) uses a low-power, red or near-infrared light source, in order to promote tissue repair, reduce inflammation and relieve pain. Early evidence suggests that PBM can have a variety of benefits, such as improved blood vessel health and even improved cognitive function.

How exactly PBM works is still a topic of research, but it appears to involve the effects of low frequency light on the enzymes within the mitochondria, the power plants of the cell. One of the results of this is the release of nitric oxide, a very important molecule for cardiovascular health.

What did the researchers do: In this study, researchers looked at the effects of PBM in 16 mice, 8 of which had been given a genetic mutation that accelerates heart ageing. Both groups of 8 mice were exposed to near-infrared light from an overhead LED source for two minutes a day, five days a week, for eight months. The researchers studied cardiac outcomes and compared them to two separate control groups, one of which carried the same mutation for accelerated heart ageing.

Key takeaway(s) from this research:

• Both treatment groups had significantly improved cardiovascular health in comparison to controls.
• Survival was significantly improved in mice with accelerated cardiac ageing, but not in other mice.
• Benefits were associated with increased circulating TGF-β1.

Both groups of mice treated with PBM had significantly less cardiac hypertrophy (enlargement), less aortic stiffness and improved ejection fraction in comparison to their equivalent control group. The genetically altered mice also had a drastically improved survival rate in comparison to their untreated controls – a 100% survival rate by the end of the study, compared with a 43% survival rate for the control group. This was linked to a rise in circulating TGF-β1, a signalling molecule with a complex role in cardiac health. TGF-β1 can protect the heart from damage and encourage repair of heart tissue.

While treatment may have increased survival rates in the altered mice, it had no significant effect on survival of the unaltered mice. If the study had lasted longer and included more mice, we might have seen a significant improvement among this group as well. Let’s hope that future studies are able to demonstrate this. A treatment that only improves survival in accelerated models of ageing is not as exciting, though it’s encouraging that unmodified mice also appeared to receive cardiovascular benefits.