Here There and Everywhere

Ah, sunlight.

There’s nothing like being outdoors on a summer morning.

What you may not know is that sunshine doesn’t just boost your mood and your vitamin D level—it also may help you ward off a heart attack or minimize the damage that one can cause, according to a new first-of-its-kind study.

I talked to the researchers to find out more about how we can all harness the power of light to brighten our heart health.

I called the study’s lead author, Tobias Eckle, MD, PhD, an associate professor of anesthesiology, cardiology and cell and developmental biology at the University of Colorado School of Medicine in Denver.

Dr. Eckle told me that our circadian rhythm—the physical, mental and behavioral changes prompted by light and darkness that occur over each 24-hour period—helps determine the level of a certain protein that can minimize the cell damage and cell death caused by a heart attack. This protein might even stop a heart attack in its tracks. So Dr. Eckle and his colleagues were eager to see whether exposure to certain kinds of light at a certain time might be effective at boosting levels of this protein.

In the study, researchers divided mice into two groups. One group was exposed to light boxes emitting light that was the same level of brightness as daylight (“bright light”), and others were exposed to regular room lighting (“regular light”). Both groups were exposed to the light first thing in the morning at 6:00 am.

Then the mice were given anesthesia and heart attacks were triggered in them. Researchers found that mice that had been exposed to three hours of “bright light” had three times the amount of the protective protein as the mice that had been exposed to “regular light”—and, incredibly, the “bright light” mice’s hearts had experienced only one-fifth as much damage!

HOW SUNNY ARE THE FINDINGS?
There are, of course, unanswered questions—for example, how the findings might apply to humans and how lasting the benefit of the protein might be.
That said, the results are promising. What’s especially interesting is that it’s the light exposure on the eyes—not the skin—that affects the protein levels, said Dr. Eckle. So humans wearing sunscreen or long sleeves wouldn’t blunt the effect.

SAFE WAYS TO LET IN THE LIGHT
Several forces have conspired over recent decades to keep people out of the sun during the day, such as indoor work and fear of skin cancer. But many people would be likely to benefit from getting more sunlight exposure as early in the morning as possible.

Here are some safe ways from Dr. Eckle to shed more light on your daily routine…

1. Take a daily walk outdoors, and keep wearing sunscreen. Even 10 to 20 minutes a day is better than nothing. Since, as I mentioned earlier, it’s the way that light affects your eyes (not your skin) that matters, apply sunscreen—that won’t dampen the benefits. The added exercise will boost your heart health, too.

2. Get sunlight while indoors. Sit near large, bright windows.

3. Use a light therapy box. If you can’t follow either of the first two tips, or if you’re at high risk for skin cancer and want to avoid UV rays at all costs, this may be the best option for you. Available online for about $50 and up, light therapy boxes mimic the brightness of sunlight while filtering out most damaging UV rays.