Sunlight is an essential component of life on earth. Beyond photosynthesis and the food chain that proceeds from it, human beings also seem to benefit from sun exposure. We need time in the sun to make vitamin D, and that in turn, helps protect us from cancer. In addition, though, scientists are beginning to ask: might sunshine be responsible for good cognitive function?
Will Sunshine Be Responsible for Better Learning and Memory?
Research from Finland suggests that people who live in sunnier neighborhoods get a boost in brain power. In the study, more than 1,800 middle-aged Finns participated in extensive cognitive testing (Scientific Reports, Dec. 2, 2022). These people, 34 to 49 years old, were volunteers in the prospective cohort study, Cardiovascular Risk in Young Finns. The investigators also calculated daily exposure to solar radiation for each participant’s zip code during several different time frames.
Researchers detected no connection between sunshine and cognitive performance for the shorter time periods of two months and one year. When they considered solar radiation over longer periods of two and five years, however, they made a discovery. Those with greater residential exposure to sunlight performed better on tests of global cognitive function. In addition, new learning, visual memory and sustained attention were better among those with at least a year of greater residential sun exposure.
There are some downsides. Specifically, people reacted more slowly. Moreover, they did not do any better on measures of executive function, which are crucial to decision-making.
Might Sunshine Be Responsible for Improved Memory?
Q. I have lived in Seattle for 35 years but this past winter I spent three months in Arizona. I have noticed a definite, dramatic improvement in my memory and I am thinking more clearly. Could this be due to the vitamin D I have gotten from sun exposure in Arizona?
I am 59 and do not take vitamins. I eat well, ride a bike about 50 miles a week and lift weights. Could sunshine be responsible for a difference in my mental ability?
A. There’s no way to know if living in the northwest led to a vitamin D deficiency. But if it did, you might have benefited from restoring your vitamin D stores to normal levels.
A research review concluded,
“Recent studies have confirmed an association between cognitive impairment, dementia, and vitamin D deficiency” (Clinical Interventions in Aging, April 2, 2014).
To learn more about vitamin D and how to make sure you are getting enough, you may want to read our Guide to Vitamin D Deficiency.