Leaving a light on when sleeping increases Body Mass Index (BMI) and waist size, research has shown.
For those who are afraid of the dark, a night light may be the best way to fall asleep, but it could wreak havoc on their health and increase risk of obesity.
“Metabolism is affected by cyclical rhythms within the body that relate to sleeping, waking and light exposure,” said Professor Anthony Swerdlow from the Institute of Cancer Research in London. Light has the ability to alter moods, physical strength, and even the way we process food in a 24-hour cycle. Disruption of sleep and circadian rhythms via light exposure could be a contributing factor to the rise in obesity, although it has not been investigated in humans.
The researchers do suggest artificial light can contribute to weight gain since it is known to disrupt the body clock by delaying the production of melatonin.
Sleeping under bulb light in night is carcinogenic
Sleeping under bulbâ€™s light in nighttime increases the risk of prostate cancer in men. Researches show that prostate cancer is more prevalent in countries where men used to go to sleep while the light is on. According to the studies, 67 out of 100 thousands men develop prostate cancer in countries where men use rarely the light for nocturnal sleeping, while this kind of cancer is 8 and 30 percent more prevalent in countries where men use light normally and excessively, respectively.
Researchers believe that using artificial light for sleeping declines secretion of melatonin hormone which in turn enfeebles body immunity system. Already the relation between sleeping under artificial light and risk of breast cancer has been diagnosed.
Night Light Decreases Childrenâ€™s Eyesight
Children who used to sleep in light rooms are threatened by the risk of poor vision five times more than others. Recent studies showed that the risk of poor vision is higher for children who use night light in their room rather children who used to sleep in a dark room.
Testing 479 children (2-16 years) indicated that children who used to sleep in light room before two years old would develop poor eyesight five times more than other children.
Children who sleep with a light on in their bedrooms at night before the age of 2 may be at significantly higher risk of developing myopia when they become older than children who sleep as infants in the dark at night, according to Dr. Richard Stone, a researcher at the Pennsylvania Ophthalmology Center.