Can LED lights cause cancer? The clickbait answer is YES, the subject is being talked about in public, but you should be careful what studies are being talked about and what conclusions are being drawn from them, and by whom.
These studies I found on the subject do not seem to indicate that if you use LED lights you will get cancer. The common conclusion seems to be: Persistent poor night sleep and a lighted bedroom may facilitate the development of cancer by disrupting melatonin production and the body’s own circadian rhythm.
Disclaimer: The author is not a medical expert and does not claim that lighting has a curative or disease-causing effect. This article has been written with an interest in the subject of lighting, with a light reading of the sources, which are linked to at the end of the article. As a writer, I hope that everyone will draw their own conclusions on the subject. The aim of this article is to provide perspectives on what LED as a technology can offer. As a company, LedStore does not offer health lights, but is interested in the effects of lighting on health and wellbeing, and in information on the subject.
Several studies have investigated the possible link between LED lights and cancer. In this article, I will go through what three different studies say about our topic.
Night lights and breast and prostate cancer
A study published in the International Journal of Cancer in 2018 assessed the association between exposure to artificial light at night (ALAN) and the risk of breast and prostate cancer in Spain. The study used data from more than 4 000 breast cancer cases and more than 2 000 prostate cancer cases and compared them with a control group of people without cancer.
The study found a significant positive association between ALAN exposure and breast cancer risk in women and a significant positive association between ALAN exposure and prostate cancer in men. The study suggests that ALAN exposure may be a risk factor for developing breast and prostate cancer. However, it is important to note that this study does not prove causality, and further research is needed to confirm these findings and understand the underlying mechanisms.
How was the research carried out?
The study used a case-control design, which is a type of observational study. The study population included 4 222 breast cancer cases, 2 095 prostate cancer cases and 4 999 controls without cancer. Participants were recruited from hospitals and primary care centres in Spain.
The study used satellite data to estimate ALAN exposure levels at participants’ residential addresses (including street lighting). The data were obtained from the Spanish National Geographic Institute and the European Space Agency. The survey also collected information on other potential risk factors for breast and prostate cancer, such as age, gender, education level, socioeconomic status and lifestyle factors (e.g. smoking, alcohol consumption and physical activity).
The study used statistical analysis to assess the association between ALAN exposure and risk of breast and prostate cancer, after adjusting for potential confounding factors.
Can LED lights cause cancer?
The study concluded that there was a significant positive association between exposure to artificial light (ALAN) at night and breast cancer risk in women, and between ALAN exposure in men and prostate cancer. The study therefore suggests that ALAN exposure may be a risk factor for the development of breast and prostate cancer in Spain.
It is important to note that this study does not establish a causal link between ALAN exposure and cancer, but it does suggest a link between the two. The study was also conducted in Spain and the results may not be generalisable to other populations or cultures with different ALAN exposure or other cancer risk factors.
In addition, the study did not take into account the possible influence of other environmental factors, such as electromagnetic fields, on the development of cancer. The study also did not take into account the duration of exposure to ALAN, which may be an important factor in the development of cancer. Further research is therefore needed to confirm these results and understand the underlying mechanisms.
Study on breast cancer in female rats
In a study published in the journal Environmental Research in 2020, exposure to blue-enriched white LED light at night increased the risk of breast cancer in female rats. The study found that exposure to this type of light led to an increase in the number of tumours in breast tissue.
How was the research carried out?
In the study, the researchers exposed female rats to blue-enriched white LED light for 12 hours a day for two years, the equivalent of a human lifespan.
The rats were divided into two groups: one group was exposed to blue-enriched white LED light, while the control group was exposed to normal lighting conditions.
Can LED lights cause cancer, conclusion 2?
The conclusion of the study is that exposure to blue-enriched white LED light may increase the risk of breast cancer in female rats. The study found that rats exposed to blue-irradiated white LED light had a significant increase in the number of breast tumours compared to the control group. The study also found that exposure to blue-enriched white LED light disrupted the rats’ circadian rhythms, the internal biological processes that regulate sleep-wake cycles.
The study authors suggest that the increased risk of breast cancer in rats exposed to blue-enriched white LED light may be due to the suppression of melatonin, a hormone that affects sleep-wake regulation and has been shown to have cancer-preventing properties .
This study is the first to show a direct link between exposure to blue-enriched white LED light and increased breast cancer risk in rats (by inhibiting melatonin production). However, further research is needed to confirm these findings in humans. It is important to note that the study was done in rats, and further research is needed to confirm whether the same results can be observed in humans.
Circadian disruption caused by night lights
A 2018 study published in the journal Cancer Epidemiology, Biomarkers & Prevention found that nighttime exposure to outdoor lighting, which can be caused by streetlights and other outdoor lighting, was associated with a higher risk of prostate cancer. The study also found that exposure to high levels of blue light at night was associated with a higher risk of prostate cancer.
How was it done?
The study investigated the possible association between exposure to artificial light at night (ALAN) and the risk of breast and prostate cancer.
The study used data from the American Cancer Society, Cancer Prevention Study II (CPS-II) cohort of more than 190,000 men and women who were followed for an average of 12 years. Participants were asked about their sleeping habits and exposure to artificial light at night, including the use of night lights, room lights and street lights.
The researchers used statistical methods to analyse the data and correct for potential confounding factors such as age, body mass index (BMI), physical activity and alcohol consumption.
Can LED lights cause cancer, conclusion 3?
The study concludes that exposure to artificial light at night (ALAN) is associated with an increased risk of breast and prostate cancer. The researchers found that women who reported using night light had a 24% higher risk of breast cancer and men who reported being exposed to room light while trying to sleep had a 34% higher risk of prostate cancer.
The study authors suggest that the increased cancer risk may be due to circadian rhythm disturbances, which are internal biological processes that regulate the sleep-wake cycle. However, it is important to note that this was an observational study, and further research is needed to confirm these findings, and furthermore, the authors of the study state that their findings are only associations and not causal.
General conclusion from the data
Can LED lights cause cancer? Freely interpreted, these studies do not, as it is important to note that these studies do not prove causality, and further research is needed to confirm these findings and understand the underlying mechanisms. It is also important to note that LED lights on the ceiling of your home or office are not the only source of blue light, as many electronic devices such as smartphones, tablets and laptops also emit blue light. Also the sun. In all the studies, the researchers found that exposure to cancer was due to a disturbance of the human internal clock. If there was one thing I learnt from these, it was that I don’t sleep with the lights on and that it’s a good idea to close the curtains for a better night’s sleep.
Sources and studies you can read about LED lights and cancer
- Evaluating the Association between Artificial Light-at-Night Exposure and Breast and Prostate Cancer Risk in Spain
- “Exposure to blue-enriched white LED light increases the risk of breast cancer in female rats”
- “Artificial Light at Night (ALAN) and breast cancer incidence worldwide: a revisit of earlier findings with analysis of current trends”
- “Light pollution as a factor in breast and prostate cancer
Other articles on led lights and health
- Led lights reduce eye strain
- Do led lights help with depression
- The effects of LED lights on our circadian rhythm
- Use of LED lights in the treatment of seasonal affective disorder (SAD)
- Led lights improve sleep
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