New Study Reveals Another Benefit Of Getting Sunlight During The Day
Taking your coffee outside or squeezing in a lunchtime walk might do more than break up your workday. Daylight helps regulate your body's internal clock, which influences sleep, blood sugar, and blood pressure.
And now, new research explores another possible benefit of daytime light exposure, looking at how it may affect our heart, kidney, and metabolic health.
About the study
Researchers analyzed data from U.S. adults who participated in the National Health and Nutrition Examination Survey. Participants wore wrist devices that measured their light exposure during the day and night, allowing researchers to track their exposure more objectively than self-reported data.
The researchers wanted to understand how light exposure was connected to cardiovascular-kidney-metabolic (CKM) syndrome, a condition involving overlapping health issues affecting the heart, kidneys, and metabolism. They also examined whether light exposure was linked to overall survival.
More daytime light was linked to better metabolic health
People with higher overall and daytime light exposure tended to have less severe CKM syndrome and a lower likelihood of advanced disease.
Spending more time in light measuring over 1,000 lux was also associated with a lower likelihood of advanced CKM syndrome.
For reference, a lux is a unit used to measure light intensity, or how bright an environment is. A reading of 1,000 lux represents relatively bright light, commonly found outdoors during the day.
Nighttime light exposure, meanwhile, showed no clear link to CKM severity on its own.
Among people with CKM syndrome, greater daily and daytime light exposure was initially linked to better survival during the study period. However, this link weakened and was no longer clear after researchers accounted for how severe participants' CKM syndrome was at the start.
Vitamin D levels partially explained the connection between light exposure and survival, but do not explain how light exposure is linked to advanced CKM syndrome.
How light influences your body's internal rhythms
Daylight helps set your circadian rhythm, the internal clock that regulates your sleep-wake cycle. This clock also influences blood sugar, blood pressure, and how your body uses energy.
Getting enough light during the day helps keep these processes aligned with the natural day-night cycle. This could explain why daytime light exposure was associated with better CKM health in the study.
Still, an association doesn't prove cause and effect. The research can't establish that getting more daylight prevents heart, kidney, or metabolic disease. External factors, like physical activity, could also influence the findings. Genetic analyses produced mixed results, so more research is needed.
Simple ways to get more daylight
You don't need to spend hours outside to see these benefits. There are lots of ways to increase daytime light exposure with simple habit adjustments. For example...
- Take your morning coffee outside: Get some natural light before settling into your day.
- Move your lunch break outdoors: A short walk gives you a chance to enjoy daylight and move your body.
- Work near a window: Natural light indoors can help, although outdoor light is generally much brighter.
- Dim the lights after sunset: Lower indoor lighting and limit bright screens before bed to support your natural sleep-wake rhythm.
The takeaway
Your circadian rhythm does more than tell you when to feel sleepy, and daylight helps keep it on track.
This study suggests daylight may play a role in how your body manages metabolic health, giving you yet another reason to prioritize getting outside. A quick walk around the block will do more than break up your day, it may support your health, too.
