Alzheimer’s disease is a progressive neurodegenerative disease and the most common form of dementia. People with Alzheimer’s disease may have difficulty remembering information, problems with learning, sleep disruptions, poor judgment, and changes in mood, behavior, and personality. An estimated 70% of people will experience sleep disruptions and 90% will experience psycho-behavioral symptoms such as apathy, depression, or agitation. 

What if there was a way to reduce and mitigate these symptoms? To provide relief and stop cognitive decline? According to Rebecca Dyer in Science Alert, researchers from Weifang Medical University evaluated photobiomodulation, a form of light therapy, as a potential intervention to reduce cognitive decline, sleep issues, and psycho-behavioral symptoms. 

Light Therapy for Alzheimer’s Disease: An Assessment 

In a meta-analysis of fifteen studies comprising 598 people with Alzheimer’s disease, researchers evaluated the impact of photomodulation on sleep, mood, and behavior. The researchers write in Plos One that: 

Our meta-analysis revealed that light therapy significantly improved sleep efficiency, increased interdaily stability, and reduced intradaily variability. With respect to psychotic behavior, light therapy was found to alleviate depression as well as reduce agitation and caregiver burden.

Why could this be? First, the researchers suggest that people with Alzheimer’s disease often spend less time outside and less time with others. They can have light sensitivity and eye problems. Less light exposure can cause health problems. By mimicking sun exposure, photobiomodulation provides an opportunity to reverse these negative effects. Further, photomodulation has also been proven efficacious in treating seasonal affective disorder (SAD). 

However, despite the positive results, the researchers caution that more research is needed to understand if photobiomodulation is safe and effective in Alzheimer’s disease. They note that:

• People in the trial had mild-to-moderate dementia, so it’s unclear how well photobiomodulation might work in those with moderate-to-severe disease. 
• The studies used in the meta-analysis had unclear randomization and potential bias, patient population inconsistencies, dementia type and severity inconsistencies, and small sample sizes. Therefore, not all of the data is necessarily usable, replicable, or forthright. 
• We don’t yet know if there are any adverse reactions linked to photobiomodulation. 

Therefore, the findings from this study show how photobiomodulation could potentially treat Alzheimer’s disease, but additional research and larger trials should first be explored to better understand the actual impact of this therapy and to develop deeper knowledge on both safety and efficacy.