Are you staring at your smartphone or computer screen for too long? Think twice about it! The blue light can trigger a craving for the sweet stuff — at least in rats.
Image: Imago
Advertisement
The blue light of smartphones and all of our other favorite devices isn't good for our biorhythm. We all know that.
We have special sensory cells that react to the cool white light and control the body's day-night rhythm. While the natural light actually becomes weaker and more yellowish in the evening hours, the light from the smartphone delays melatonin production, for example. This means it's more difficult to fall asleep and sleep deeply, and we don't feel as rested the next day.
But we have accepted that — and keep staring at our smartphones, tablets and computers. Who needs sleep when you can be online 24/7? In any case, this might apply to the majority of us, right?
Blue light receptor
02:55
This browser does not support the video element.
But let's get to the point. The blue light might trigger something else: a craving for sugar!
A new study shows that rats exposed to blue light for an hour in the evening consume more sugar. As a result, their blood sugar levels rise and glucose tolerance changes. Researchers led by Anayanci Masís-Vargas and colleagues from the University of Strasbourg and the University of Amsterdam have demonstrated this correlation in male rats.
In their study, the team changed the rhythm of the the typical nocturnal laboratory rats in order to better model human light exposure. This means that the animals were awake during the day and slept at night. The researchers exposed the rats to the disturbing white-blue light for an hour at night.
The rats were given the opportunity to choose between a balanced midnight snack — their regular rodent food — or to prefer a mixture of water, lard and sugar water.
The researchers observed that the male animals drank more sugar during the night when they were exposed to blue light than they did during the nights without blue light.
In addition, glucose tolerance was altered in male rats, a warning sign of type-2 diabetes. Doctors speak of this when blood sugar levels are too high.
Earlier research had already shown a strong connection between obesity and artificial light at night. That's because much of the artificial light we are exposed to today comes from LED lights and LED screens that emit a high level of blue light. The retinal cells of the eye are particularly sensitive to this blue light and transmit information directly to the appetising areas of the brain.
Be consistent
This particular study in conjunction with previous work clearly shows that blue light at night is disturbing and that the use of the screen at night can increase our craving for sweet treats — and impair our ability to process this sugar, especially in men.
Although the rats were tested after only one night's exposure to light, this could lead to weight gain and diabetes over time, the researchers said.
"Limiting the amount of time that we spend in front of screens at night is, for now, the best measure to protect ourselves from the harmful effects of blue light", concludes Masís-Vargas.
In case it's necessary to be exposed to devices at night, he would recommend the use of apps and night mode features on the devices, which turn the screens more orange and less blue or the use of blue light filtering googles that are already available on the market.
Bitter truth about sugar
Sugar is tasty, but not exactly good for you. Consumption of the sugary stuff is rising, and that’s having an impact on health. The WHO has warned of a “global epidemic.” Here are a few facts you really should know.
Image: Colourbox
Sugar makes you fat!
Sugar is converted to fat in the body about two to five times more quickly than starches. In other words, when we consume sugar, we’re feeding our fat cells. The fructose in sugar is also metabolized by the liver, which can contribute to fatty liver disease. That can promote insulin resistance and lead to Type 2 diabetes – with a lifelong impact on your health.
Image: Colourbox
Sugar affects your mood!
In small amounts, sugar promotes the release of serotonin, a hormone that boosts mood. But too much sugar can promote depression and anxiety. Sudden shifts in blood sugar levels can also lead to irritability, anxiety and mood swings.
Image: Colourbox
Sugar contributes to aging!
We already know that sugar has a variety of health effects, but it also affects the skin. That’s in part due to glycation, the process whereby sugar molecules bind to collagen fibers. As a result, the collagen fibers lose their natural elasticity. Excess sugar also damages microcirculation, which slows cell turnover. That can promote the development of wrinkles, make you look older than your age.
Image: Colourbox
Sugar is harmful to your gut!
The microflora of your gut promote digestion and protect your digestive system from harmful bacteria. Consuming too much sugar gets your gut microflora out of whack. Fungi and parasites love sugar. An excess of the Candida albicans yeast can lead to a host of annoying health symptoms. And sugar also contributes to constipation, diarrhea and gas.
Image: Colourbox
Sugar can be addictive!
In overweight people, the brain responds to sugar by releasing dopamine, in much the same way that it responds to alcohol or other addictive substances. Test it yourself: avoid all sugary foods and beverages for ten days. If you start to get headachy and irritable after a day or two, and start craving sugar, then you could be suffering from sugar withdrawal.
Image: Colourbox
Sugar makes you aggressive!
People who consume excess sugar are more likely to engage in aggressive behavior. Children with ADHD are also affected by sugar. For these children, too much sugar affects concentration and promotes hyperactivity. That’s why it’s a good idea for children to avoid eating sugar during school hours.
Image: Colourbox
Sugar weakens the immune system!
Excessive sugar consumption makes it harder for the immune system to ward off disease. After consuming sugar, the immune system’s ability to kill germs is reduced by up to 40 percent. Sugar also saps the body’s store of vitamin C, which white blood cells need to fight off viruses and bacteria. Sugar also promotes the inflammatory response, and even minor inflammation can trigger numerous diseases.
Image: picture-alliance/dpa
Sugar promotes Alzheimer’s disease!
Studies have shown that excess sugar consumption increases the risk of developing Alzheimer’s disease. A 2013 study showed that insulin resistance and high blood sugar values – both of which are common in diabetes – are associated with a higher risk of neurodegenerative diseases such as Alzheimer’s.
Image: Colourbox
Sugar increases cancer risk!
Cancer cells need sugar to proliferate. An international research team headed by Lewis Cantley of Harvard Medical School is researching how sugar might contribute to the growth of malignant cells. He believes that refined sugar may be what causes cancer cells to develop into tumors. He’s still testing that hypothesis but recommends that even slender people consume as little sugar as possible.
Image: Colourbox
Sugar makes you stupid!
Excess sugar consumption may have a negative impact on memory. According to a study carried out by Berlin’s Charité University Hospital, people with high blood sugar levels have a smaller hippocampus – the part of the brain that’s key to long term memory. In the study, people with high blood sugar also performed more poorly on tests of memory than those with low blood sugar levels.
