The research also suggests that this procedure could benefit humans, and the researchers outline the reason why.
"We already knew that intense light can protect against heart attacks, but now we have found the mechanism behind it," says the study's senior author Dr. Tobias Eckle, professor of anesthesiology at the University of Colorado School of Medicine in Aurora.
Boosting specific gene protects heart
In the study, the researchers discovered that intense light influences the functions of the PER2 gene, which is expressed by a part of the brain that controls circadian rhythms.
By boosting this gene through intense light therapy, the researchers discovered that the mice's heart tissue received extra protection when it experienced issues with oxygen, such as during a heart attack.
Additionally, this intense light also heightened cardiac adenosine, which is a specialized chemical that helps with blood flow regulation. In concert, both benefits helped protect heart health.
Also, when they studied the mice, the researchers found that being able to physically perceive light was vital, as blind mice experienced no benefits from the intense light.
Humans had similar benefits
The next step was to see if humans could benefit from light therapy. The researchers worked with healthy human volunteers and exposed them to 30 minutes of intense light.
On five consecutive mornings, the researchers exposed the participants to 10,000 lumens of light and drew blood several times.
The researchers found that PER2 levels increased in response to light therapy in the human participants as it did in the mice. They also reported that the human volunteers saw a decreased level of plasma triglycerides and improved metabolism.
Dr. Eckle explained that light plays an essential part in human health, not only in regulating the circadian rhythm but in cardiovascular health as well.
He adds that according to prior studies, more people throughout the U.S. experience heart attacks during the darker months of winter, even in states that traditionally get more sunshine, such as Hawaii and Arizona.
Heart disease and its impact on U.S. adults
Heart disease is widespread throughout the United States. Around 610,000 people die from heart disease every year, which accounts for 1 out of every 4 deaths.
Coronary heart disease is the most common form of heart disease, and around 735,000 people in the U.S. experience a heart attack annually.
While most people know that chest pain is a sign of a heart attack, other less obvious signs include shortness of breath, upper body pain, nausea, cold sweats, lightheadedness, and discomfort in the arms, back, neck, jaw, or upper stomach.
There are many ways that people can reduce their risk of developing heart disease, such as eating better and exercising more. However, it is vital that research to discover new ways to protect the cardiovascular system continues.
This study using intense light highlights how something seemingly unrelated to heart health can have such protective benefits.
This study could have a significant impact on the treatment of heart patients in the future. Eckle says that "if the therapy is given before high risk cardiac and non-cardiac surgery, it could offer protection against injury to the heart muscle which can be fatal."
Eckle believes there are other possibilities, too, adding that "drugs could also be developed that offer similar protections based on these findings."