Exposure to blue light, such as that emitted by smartphones or tablets, may cause early puberty in male rats, according to a study presented at the 61st Annual Meeting of the European Society of Pediatric Endocrinology in The Hague. The results of this study were also published in Frontiers in Endocrinology.
This study is the first to investigate the relationship between blue light exposure and early puberty in male rats and reveals how environmental factors such as screen time affect early puberty and testicular tissue, ultimately potentially leading to future prevention strategies for children.
Most children experience puberty prematurely for no apparent reason. Sometimes it's due to genetics, sometimes it's a problem with the brain, such as an injury or tumor, and sometimes it's a problem with the thyroid, adrenals, or gonads.
In recent years, several studies have reported an increase in early puberty in both girls and boys, especially during the COVID-19 pandemic. One factor may be the increasing use of blue light-emitting devices, but this is difficult to assess in children.
In the study, researchers at Bilkent Municipal Hospital and Gazi University in Ankara, Turkey, examined 18 21-day-old male rats that were divided into three groups of six and exposed to a normal light cycle, 6 hours, or 12 hours of blue light.
The researchers found that male rats exposed to blue light showed the first signs of puberty significantly earlier. Additionally, the longer the mice were exposed to blue light, the earlier puberty began, and they also showed suppressed sperm development and damaged testicular tissue.
A previous study by the same research team also showed that puberty starts earlier in female rats due to exposure to blue light. However, this association has never been studied in male rats before.
"For the first time, we have found a direct relationship between blue light exposure and early puberty in male rats," said lead researcher Dr. Aylin Kılınç Uğurlu of Ankara's Bikent City Hospital. "Our findings are consistent with our previous studies in female rats, which also showed similar effects, providing a more complete picture of how blue light may affect puberty in male and female rats."
While the findings suggest blue light exposure may be a potential risk factor for early puberty, more research is needed. "I would like to emphasize that this is a rat study and the direct results cannot be interpreted in humans. However, we provide an experimental basis for further research into the health effects of increasing screen time in modern society," said Dr. Kılınç Uğurlu.
The researchers will next focus on assessing the effects of pre-puberty exposure to blue light in adult rats. Our goal was to expose male and female rats to blue light before puberty and to understand the long-term effects of blue light on reproductive organ damage and fertility.
Ultimately, this research will help inform preventive measures and contribute to the ongoing discussion about how modern lifestyles impact physiological development and long-term health.