Do you know: Red light linked to reduced risk of blood clots
in 2025
People and mice exposed to long-wavelength red light that can cause heart attacks, lung damage and strokes had lower blood clotting rates, according to research led by the University of Pittsburgh School of Medicine and UPMC surgeons and their published today Journal of Thrombosis and Haemostasis.
The results, which need to be verified through clinical trials, have the potential to reduce blood clots in veins and arteries, which are the main causes of preventable death worldwide.
“The light we’re exposed to can change our biological processes and change our health,” said lead author Elizabeth Andraska, MD, assistant professor of surgery in the Pitt Trauma and Transfusion Medicine Research Center and a surgical resident. vascular at UPMC. “Our findings could lead to a relatively inexpensive therapy that would benefit millions of people.”
Scientists have long linked light exposure to health outcomes. The rising and setting of the sun is the foundation of metabolism, hormone secretion, even blood flow, and heart attacks and strokes are more likely during the morning hours than at night. Andraska and her colleagues looked at whether light could affect the blood clots that lead to these conditions.
To test this idea, the team exposed mice to 12 hours of 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. Mice exposed to red light had nearly five times fewer clots than 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 underwent cataract surgery and received either normal lenses that transmit the full spectrum of visible light, or blue light-filtering lenses, which transmit about 50% less light. blue They found that cancer patients who received blue light filtering lenses had a lower risk of blood clots compared to their counterparts with traditional lenses. This is particularly significant because non-cancer patients have nine times the risk of blood clots.
“These findings solve a fascinating mystery about how the light we are exposed to every day affects our body’s response to injury,” said senior author Matthew Neal, MD, professor of surgery, Fund Watson in the Chair of Surgery and co-. director of the Trauma Medicine and Transfusion Research Center at Pitt, and a trauma surgeon at UPMC. “Our next steps are to find out why, biologically, this is happening, and to test whether exposing people at high risk of blood clots to red light reduces that risk. and the worldwide disabilities caused by blood clots.”
The recently published study shows that the optic pathway is critical – the wavelength of light had no effect on blind mice, and coagulation was unaffected by light shining directly on blood.
The team noted that exposure to red light is associated with less inflammation and activation of the immune system. For example, red-exposed mice had fewer neutrophil extracellular traps — aptly abbreviated as “NETs” — which are web-like structures made by immune cells to trap invading microorganisms. They also trap platelets, which can cause clots.
The mice exposed to red light also had increased fatty acid production, which reduces platelet activation. Since platelets are essential for the formation of clots, this results in less clot formation.
Understanding how the red light is triggering changes that could lower clotting risk could also lead scientists to better medications or therapies that could be more potent and more convenient for patients than continuous exposure to red light.
In preparation for clinical trials, the team is developing red light protective glasses to control the amount of light exposure study participants receive and investigate who will benefit most from red light.
Additional authors on this research are Frederik Denorme, Ph.D., Robert Campbell, Ph.D., and Matthew R. Rosengart, MD, all of Washington University in St. Louis. Louis; Christof Kaltenmeier, MD, Aishwarrya Arivudainabi, Emily P. Mihalko, Ph.D., Mitchell Dyer, MD, Gowtham K. Annarapu, Ph.D., Mohammadreza Zarisfi, MD, Patricia Loughran, Ph.D., Mehves Ozel, MD , Kelly Williamson, Ph.D., Roberto Mota-Alvidrez, MD, Sruti Shiva, Ph.D., Susan Shea, Ph.D., and Richard A. Steinman, MD, Ph.D., all of Pitt; and Kimberly Thomas, Ph.D., of the Vitalant Research Institute.
This research was supported by National Institutes of Health grants R35GM119526, K01AG059892, R01HL163019, R01GM147121, R01GM145674, T32HL98036 and S10OD028483, University of Pittsburgh, National Center for Shared Research Resources. 1S10OD016232-01, 1S10OD018210-01A1 and 1S10OD021505-01, American Heart Association award 2021Post830138, and an Institutional Physician Scientist Award from the Wellcome Burroughs Fund.