Gentle Light Therapy Shows Promise for Boosting Brain Function in Alzheimer’s Patients

Researchers at the Technical University of Denmark (DTU), in collaboration with UC Berkeley and the spin-out company OptoCeutics, have developed a promising light-based therapy that may improve cognitive function in people with Alzheimer’s disease—without the need for medication or invasive procedures. The innovation centers on a noninvasive light stimulation device that induces beneficial brain wave activity simply by sitting near it.

The technology builds on earlier research from MIT, which showed that exposing mice with Alzheimer’s to flickering lights could stimulate gamma brain waves—oscillations around 40 Hz that are associated with attention, memory, and perception. In those studies, gamma wave stimulation helped reduce harmful beta-amyloid plaques in the brain, a hallmark of Alzheimer’s pathology. However, flickering lights can cause discomfort and even trigger seizures in sensitive individuals, making them unsuitable for human use.

To solve this, DTU Professor Paul Michael Petersen and his team developed a gentler alternative: a light source that subtly induces gamma waves without visible flickering. Users can sit in front of the lamp and go about their daily activities while the device quietly stimulates brain activity. The light appears continuous to the eye, but it’s engineered to deliver the same neurological benefits as flickering light—without the side effects.

Early clinical trials conducted at Zealand University Hospital in Roskilde have shown encouraging results. Patients with mild to moderate Alzheimer’s who used the light therapy demonstrated improved cognitive performance, particularly in areas like speech and memory. A larger study is now underway to confirm these findings and explore long-term effects.

The goal is to eventually embed this technology into everyday lighting—such as desk lamps or ceiling fixtures—so that people can receive therapeutic stimulation passively at home. This could be especially valuable for early intervention or preventive care in aging populations.

The device represents a new class of “non-pharmaceutical neurotherapies” that use light to modulate brain function. It’s part of a growing movement to explore how sensory stimulation—whether through light, sound, or touch—can influence neurological health. Unlike drugs, which often come with systemic side effects, light therapy offers a localized, low-risk alternative that could complement existing treatments or serve as a standalone option.