New study suggests light therapy may be effective at slowing cardiovascular aging, reducing age-related heart deterioration.
Light therapy has demonstrated its usefulness in treating a variety of diseases, from mental health through to psoriasis and acne. But can it delay the occurrence of age-related disease?
Longevity.Technology: It would seem the answer to that question might be yes. According to a study in mice published in Lasers in Surgery and Medicine, photobiomodulation (PBM) therapy, a form of low-dose light therapy which has previously been noted to be effective in several age-associated chronic diseases such as hypertension and atherosclerosis, mitigated age-associated reduced cardiac function, improving neuromuscular coordination and increasing longevity.
Cardiovascular diseases are the leading cause of death globally, taking an estimated 17.9 million lives each year; almost 20% of Americans aged over 65 have been diagnosed with heart disease, and heart disease continues to be the leading cause of death in the US.
Praveen Arany, a University at Buffalo expert in PBM and Edward G Lakatta of the National Institute on Aging (part of the National Institutes of Health) examined the effects of PBM therapy on age-associated cardiovascular changes in a mouse model of accelerated cardiac aging .
“The idea was to see if intervention in middle age could enable people to avoid further age-related heart deterioration,” says Arany, associate professor of oral biology in the School of Dental Medicine, and co-PI with Lakatta on the study .
The study focused on heart condition and function in middle-aged mice – those at the grand old age of 14 months. The research showed an improvement in heart function after exposure to PBM therapy and PBM also mitigated the thickness of the cardiac wall.
“As muscle thickens, it becomes stiffer, and the pumping action of the heart is less effective,” Arany says . Gait symmetry – observing how mice performed comfortably on a treadmill – also improved, suggesting an improvement in neuromuscular coordination.
The experiment exposed mice to a dose of near-infrared light by using an overhead LED light source rather than a focused light source. The ambient low-dose exposure took place five days a week for two minutes each day.
One group of the genetically manipulated mice are bred to develop severe heart disease, which usually causes death; however, after treatment with PBM, heart disease among these manipulated mice did not progress. The survival rate among the most susceptible group was and impressive 100%, compared with the usual survival rate of 43%. The results were significant, even though the eight-month study was interrupted for three months by COVID-19.
Light at the end of the tunnel
This study on the heart begins, unusually, in the mouth – Arany began his professional career as a dentist.
“After a tooth extraction, we have to wait for the wound to heal before we can proceed with treatment,” he explains. “I became interested in how to improve and hasten healing.” He soon learned that exposing the wound to light promoted healing, and his interest in light therapy began.
The study showed the production of a substance called transforming growth factor beta (TGF-β1) correlated to exposure to PBM, suggesting that PBM triggers activation of TGF-β1. The substance plays an important role in human health and disease, especially in age-related diseases. Arany says TGF-β1 regulates stem cell activity, inflammation and immune system function, and that may partly explain why light therapy works.
The next steps
Like all treatments, light therapy is only effective if it is administered with appropriate parameters. To be effective and safe, it is important to use specific light wavelength (color), intensity (dose) and length of exposure.
Certain kinds of light, such as ultraviolet light and light produced by lasers, can be harmful, and other lights, while harmless, may not be effective. This study shows that long-term exposure to a low-dose near-infrared light in a non-thermal manner, carefully adjusted, may benefit heart health and longevity. The next step, Arany says, is controlled human clinical trials.