Scientists have discovered that exposure to red light may help reduce the risk of dangerous blood clots, which are a leading cause of heart attacks, strokes, and lung damage.
Researchers from the University of Pittsburgh School of Medicine and UPMC found that both humans and mice exposed to red light developed fewer blood clots.
This finding, recently published in the Journal of Thrombosis and Haemostasis, could lead to an accessible, low-cost treatment that might save countless lives.
Blood clots form when platelets, small cell fragments in the blood, stick together. While they play a crucial role in stopping bleeding, excessive clotting can block blood flow and cause life-threatening conditions.
Clot-related illnesses are a major global health problem, and finding new ways to lower the risk has become a pressing focus for researchers.
Scientists already know that light affects our body in many ways. For example, sunlight regulates our sleep cycles, metabolism, and hormone levels.
It’s also known that heart attacks and strokes are more likely to occur in the early morning, a time influenced by our body’s natural rhythms. Inspired by these patterns, researchers wondered if different types of light could influence blood clotting.
To explore this idea, the team exposed mice to different types of light for 12-hour periods: red, blue, or white. After three days, they examined the mice for blood clots.
The results were striking—mice exposed to red light developed five times fewer clots compared to those exposed to blue or white light. Importantly, the mice’s eating, sleeping, activity, weight, and body temperature stayed the same, ruling out other possible causes for the difference.
The team then looked at medical records from over 10,000 cataract surgery patients. Some patients received blue light-filtering lenses, which block about half of blue light, while others received standard lenses that allow all visible light to pass through.
Among cancer patients—a group at much higher risk for blood clots—those with blue light-filtering lenses had a significantly lower risk of developing clots than those with standard lenses. This finding further supported the idea that light exposure plays a role in clot formation.
But why does red light have this effect? The researchers found some clues. In the mice exposed to red light, there was less inflammation and fewer immune system activities that promote clotting. For example, red light reduced the formation of structures called “NETs.”
These are web-like traps created by immune cells to catch harmful bacteria, but they can also capture platelets and lead to clots. Additionally, red light increased the production of certain fatty acids, which are known to reduce platelet activity. With less active platelets, clot formation naturally decreased.
Interestingly, the benefits of red light were only observed when the mice’s eyes could detect the light. Blind mice exposed to red light showed no changes in clotting, and shining light directly on blood had no effect. This suggests that the pathway involves the brain and how it processes signals from the eyes.
The team believes these findings could pave the way for new treatments. They are now working on red light goggles to test whether controlled exposure to red light could lower clot risks in people.
These goggles could be particularly helpful for high-risk groups, such as cancer patients or those recovering from surgery. The hope is to create a simple, safe therapy that could significantly reduce deaths and disabilities caused by blood clots.
This research also raises exciting possibilities for drug development. By understanding how red light influences clotting, scientists might uncover biological pathways that could be targeted with medications. Such treatments could offer a more practical alternative for people who cannot use red light therapy consistently.
While the findings are promising, further research is needed to confirm the effects in humans. Clinical trials will be crucial to determine how red light can be used safely and effectively.
If successful, this discovery could transform how we approach the prevention of blood clots, making it an important step forward in saving lives worldwide.
If you care about heart health, please read studies that vitamin K helps cut heart disease risk by a third, and a year of exercise reversed worrisome heart failure.
For more health information, please see recent studies about supplements that could help prevent heart disease, stroke, and results showing this food ingredient may strongly increase heart disease death risk.
The research findings can be found in the Journal of Thrombosis and Haemostasis.
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