Blue Light, Obesity & Diabetes

A Harvard study identified preliminary results that link blue light to diabetes and possibly obesity.

Blue Light At The Beach

The researchers put ten people on a schedule that gradually shifted the timing of their circadian rhythms similar to what occurs when you look at a screen or mobile phone. The test subject’s blood sugar levels increased, placing them into a pre-diabetic state. Their levels of leptin, a hormone that keeps people feeling full after a meal, went down.

Here’s a link to the Harvard Study: Link

Here is why. Nighttime exposure to blue light delays the nocturnal melatonin peak (shifting the circadian rhythm) which decreases the production of cortisol. A balanced consistency of cortisol is much needed to increase the body’s metabolism of glucose.

Studies showed that sleeping with a light or a television on in the bedroom is conclusively associated with gaining five kilograms or more. Also, the study showed the body mass index increase of at least 10% over five years among women. This study published in the medical journal JAMA Internal Medicine and concludes Blue Light puts us at a higher risk of being overweight or obese, compared with being exposed to no artificial light during sleep.

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Blue Light & The Immune System

While we sleep, our immune systems release sleep-promoting proteins/peptides called cytokines. The body requires specific types of cytokines to increase if you’re feeling stressed, have an infection or inflammation.

Blue Light At The Beach

Cytokines act through receptors and play an essential role in the immune system. They are moderating the balance between humoral immunity (release of antibodies that rapidly respond against toxins) and cell-based immunity (release of cytokines that permanently act against disease-causing virus/bacteria. Cytokines also regulate the maturation, growth, and responsiveness of other cell populations that respond to trauma, sepsis, cancer and reproduction.

The production of these infection-fighting antibodies and cells slow down during stages of sleep deprivation.

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Is Blue Light Linked To Cancer & Other Diseases?

Studies that can be found linked at the bottom of this page display a link between exposure to blue light at night, such as working the night shift, to types of cancer, diabetes, heart disease, and obesity. We also know that exposure to blue light suppresses the creation of melatonin, a hormone that assists with controlling our circadian rhythms, and there’s some preliminary studies that suggest lower melatonin levels might explain the association with cancer and other diseases.

That’s not all. A Harvard study identified preliminary results that link blue light to diabetes and possibly obesity. The researchers put 10 people on a schedule that gradually shifted the timing of their circadian rhythms similar to what occurs when you look at a screen or mobile phone. The test subjects blood sugar levels increased, placing them into a pre-diabetic state, and their levels of leptin, a hormone that keeps people feeling full after a meal, went down.

 

 

Furthermore, studies show that even dim light can interfere with your circadian rhythm and melatonin creation. A miniscule eight lux—the level of brightness well exceeded by most desk and table lamps and about twice that of a night light has an effect.

Stephen Lockley a Harvard sleep researcher made comment that light at night is part of the reason so many people don’t get enough sleep. Researchers have linked poor sleep patterns and lack of sleep to an increased risk for depression, as well as diabetes and cardiovascular problems.

 

Supporting Research