Bright light alters metabolism

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Exposure to bright light could affect your metabolism, reports a new Northwestern Medicine study.

Northwestern scientists found bright light exposure increased compared to dim light exposure in both the morning and the evening. In the evening, bright light also caused higher peak glucose () levels.

Insulin resistance is the body's inability to adequately move glucose out of the bloodstream, resulting in a buildup of blood sugar. Over time, the excess blood glucose could result in increased body fat, weight gain and a higher risk for diabetes.

"These results provide further evidence that bright light exposure may influence metabolism," said Kathryn Reid, senior study author and a research associate professor of neurology at Northwestern University Feinberg School of Medicine.

"It's cool that bright light has this effect, but we don't understand why yet," Reid said. "In theory, you could use light to manipulate metabolic function."

Previous research by Northwestern scientists showed that people who received the majority of their bright light in the morning weighed less than those who were exposed to most of their bright light after 12 p.m. The researchers wanted to understand why. Mouse studies also have shown that mice kept in constant light have altered and gain weight compared to control mice.

"Our findings show that insulin was unable to acutely bring back to a baseline level following a meal with exposure in the evening," said first author Ivy Cheung, a postdoctoral fellow in neurology at Feinberg. "The results of this study emphasize that our lighting environment impacts our health outcomes."

The paper was published May 18 in the journal PLOS ONE.

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More information: Ivy N. Cheung et al. Morning and Evening Blue-Enriched Light Exposure Alters Metabolic Function in Normal Weight Adults, PLOS ONE (2016). DOI: 10.1371/journal.pone.0155601
Journal information: PLoS ONE

Citation: Bright light alters metabolism (2016, May 19) retrieved 12 July 2020 from
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