Exposure to Red Light Linked to Lower Risk of Blood Clot: Study Finds - Video

Humans and mice exposed to long-wavelength red light had lower rates of blood clots that can cause heart attacks, lung damage and strokes, according to research published in the Journal of Thrombosis and Haemostasis.

The findings, which need to be verified through clinical trials, have the potential to reduce blood clots in veins and arteries, which are leading causes of preventable death worldwide.

The team exposed mice to 12 hours of either red, blue or white light, followed by 12 hours of darkness, in a 72-hour cycle. They then looked for differences in blood clots between the groups. The mice exposed to red light had nearly five times fewer clots than the mice exposed to blue or white light. Activity, sleep, eating, weight and body temperature remained the same between the groups.

The team also analyzed existing data on more than 10,000 patients who had cataract surgery and received either conventional lenses that transmit the entire visible spectrum of light, or blue light-filtering lenses, which transmit about 50% less blue light. They discovered that cancer patients who received blue light-filtering lenses had lower risk of blood clots compared to their counterparts with conventional lenses. This is especially notable because cancer patients have nine times the risk of blood clots of non-cancer patients.

The recently published study indicates that the optic pathway is key – light wavelength didn’t have any impact on blind mice, and shining light directly on blood also didn’t cause a change in clotting.

The mice exposed to red light also had increased fatty acid production, which reduces platelet activation. Since platelets are essential to forming clots, this naturally leads to less clot formation.

“These results are unraveling a fascinating mystery about how the light to which we’re exposed on a daily basis influences our body’s response to injury,” said senior author Matthew Neal, M.D., professor of surgery, Watson Fund in Surgery Chair and co-director of the Trauma and Transfusion Medicine Research Center at Pitt, and trauma surgeon at UPMC. “Our next steps are to figure out why, biologically, this is happening, and to test if exposing people at high risk for blood clots to more red light lowers that risk. Getting to the bottom of our discovery has the potential to massively reduce the number of deaths and disabilities caused by blood clots worldwide.”

Reference: Alterations in visible light exposure modulate platelet function and regulate thrombus formation, Andraska, Elizabeth A. et al. Journal of Thrombosis and Haemostasis, Volume 23, Issue 1, 123 - 138