Bright light alters metabolism and increases insulin resistance

(NaturalHealth365) Bright light exposure seems to influence our metabolism. Although researchers aren’t entirely sure why, they’re hoping this effect could be used to manipulate metabolic function in positive ways.  One thing is certain: insulin resistance and blood sugar imbalances do occur with the overexposure of artificial light – especially at the wrong time of the day.

For example, scientists from Northwestern University Feinberg School of Medicine have found that bright light exposure in the morning and evening increases insulin resistance compared with dim light exposure at these times.

Evening bright light exposure can cause high blood sugar

Evening exposure to bright light leads to higher peak glucose levels and insulin resistance as well.  And, just to be clear, insulin resistance refers to the inability to move glucose from the bloodstream adequately, and the result is high blood sugar. Over time, excess body fat and higher diabetes risk can occur.

Previous studies related to light exposure have shown that those who received most of their exposure to bright light after 12 pm tended to be heavier than those who were exposed earlier in the day. Mice kept in constant light eventually have altered metabolism related to glucose. This makes them more likely to gain weight than mice not exposed to high amounts of light.

In these cases, insulin could not effectively bring glucose back to baseline levels after a meal during evening bright light exposure. The study results emphasize how daily light exposure and our environment impacts health.

Timing is everything when it comes to bright light exposure

These results point to the influence of dark and light exposure times. It’s important to find the ideal pattern for ideal health. The recent Northwestern study examined the immediate effects of three hours of exposure to blue-enriched light in the morning or evening compared with dim light at these times. Its effects on metabolic function, hunger and physiological arousal were all studied and tracked.

Nineteen adults in good health were divided into a morning bright light exposure group (0.5 hours after waking) and an evening group (10.5 hours after waking). Results were then compared with each person’s dim light exposure results to create a baseline. The evening group ate their dinner in light, while the morning group ate their breakfast while exposed to bright light.

Results showed that blue-enriched light exposure altered metabolic functioning acutely in both groups compared with dim light exposure. While both resulted in higher insulin resistance, the evening exposure caused higher peak blood glucose levels. The results show the inability of insulin to manage increased blood sugar in the evenings.

Cancer-fighting melatonin influenced by bright light exposure

Artificial light confuses the brain’s pineal gland, and this can disturb melatonin production.  Melatonin regulates our sleep cycles, but it is also a cancer-fighting substance.

Melatonin also prevents neurodegenerative diseases by regulating circadian rhythms, mood, sleep quality, and more. It cleans up free radicals and has antioxidant and immunomodulatory qualities. When melatonin production is impaired, we are at higher risk for cancer and other health issues.

Being proactive about exposure to light throughout the day can bring a range of health benefits.   To learn more about how to protect yourself from the negative effects of artificial light – listen to the NaturalHealth365 Podcast, “Blue light therapy.”

References:

https://www.sciencedaily.com/releases/2016/05/160518141416.htm

http://www.northwestern.edu/newscenter/stories/2016/05/web/bright-light-alters-metabolism.html

http://www.naturalhealth365.com/blue-light-melatonin-production-1442.html