What Is Blue Light? How Does It Impact Sleep?

Updated Dec 14, 2024 | 10:45 PM IST

SummaryScreens of electronic devices such as smartphones, computers, tablets, and televisions emit blue light. But does it impact your natural sleep cycle and circadian rhythm?
Blue Light

Blue Light (Credit: Canva)

Blue light emitted by devices like smartphones, computers, and televisions is becoming a major factor disrupting our sleep cycles. Research reveals that a significant number of Americans use electronic devices close to bedtime, contributing to poor sleep quality. Reducing exposure to blue light, particularly in the evening, is a simple yet effective way to help your body prepare for restful sleep.

What Is Blue Light?

Blue light is part of the visible light spectrum and is emitted by natural and artificial sources like the sun, fluorescent lights, LED lights, and digital screens. This wavelength is known for influencing our alertness, mood, and sleep patterns. During the day, blue light plays a role in regulating circadian rhythms, helping us stay alert and focused. However, exposure to it in the evening can have a detrimental effect on sleep quality.

How Does Blue Light Impact Circadian Rhythms?

Circadian rhythms are 24-hour cycles that control essential bodily functions, including sleep. Light is the primary factor that aligns these rhythms with day and night. Historically, exposure to sunlight during the day helped set our body clocks, signaling when to be awake and when to sleep. However, the widespread use of artificial lighting and electronic devices has introduced more light exposure after dark, disrupting these natural cycles.

Blue light, in particular, has the strongest impact on circadian rhythms. During daylight hours, blue light helps us feel alert by stimulating the brain, raising body temperature, and increasing heart rate. But in the evening, exposure to blue light can confuse the body’s internal clock, suppressing melatonin—the hormone responsible for making us feel sleepy. As a result, our brains may remain in “daytime mode,” preventing us from winding down for the night.

Health Consequences Of Disrupted Sleep

Persistent disruption of circadian rhythms can lead to a range of health issues, including metabolic disorders, poor mental health, and increased risk for conditions like depression and anxiety. Furthermore, the inability to sleep well at night affects cognitive performance, mood, and overall well-being. Chronic exposure to blue light in the evening may significantly contribute to these negative health outcomes.

Devices That Emit Blue Light

Many common devices in our daily lives emit blue light, including:

- Smartphones and tablets

- Computer monitors and laptops

- Televisions and e-readers

- LED and fluorescent lighting

- Video game consoles

How To Minimize Blue Light Exposure

To reduce the effects of blue light on your sleep, here are some practical strategies:

1. Turn off screens before bed: Try to avoid using electronic devices at least two to three hours before bedtime. Reducing screen time helps prevent blue light from interfering with melatonin production.

2. Adjust your lighting: Dim your home’s lights or switch to warmer-toned lighting in the evening. You can also use lamps with red or orange light, which are less likely to impact your circadian rhythms.

3. Night mode settings: Many smartphones and computers have a "night mode" feature that reduces blue light emission. Make use of these features to limit exposure in the hours leading up to bedtime.

4. Blue light-blocking glasses: Special glasses designed to filter out blue light may be helpful for some individuals. These glasses can block or reduce the melatonin-suppressing effects of blue light.

5. Apps for blue light reduction: There are several smartphone and computer apps available that reduce blue light emission, allowing you to use your devices before bed without disturbing your sleep.

6. Create a sleep-friendly environment: If you can’t control light sources in your bedroom, consider using an eye mask to block out ambient light and promote better sleep.

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50 Per Cent Preventable Cancers Caused By 2 Lifestyle Habits: Study

Updated May 26, 2026 | 01:07 PM IST

SummaryAir pollution, too, has recently contributed to a surge in lung cancer cases.
Drinking beer

Drinking alcohol is one of the risk factors for cancer. (Photo credit: iStock)

Cancer is one of the most dreaded diseases. It is characterised by a malignant tumor that obstructs the normal functioning of organs. According to a recent analysis from the World Health Organisation (WHO), more than a third of cancer cases in the world are preventable. Cervical, stomach, and lung cancers make up half of the cases. This implies that millions of such deadly cases in the world can be prevented with behavioural changes, timely medical intervention, reduced occupational risks, and an ability to tackle environmental pollutants. It turns out that most preventable cancers can be avoided by making two simple lifestyle changes.

Preventable cancers in the world

Researchers say that addressing preventable causes represents one of the most powerful opportunities to reduce the global cancer burden. The analysis also noted that, in 2022, there were approximately 19 million new cases of cancer, and 38 per cent were related to 30 modifiable risk factors. The most common modifiable risk factors are:

  1. High BMI
  2. Smoking
  3. Insufficient physical activity
  4. Alcohol intake
  5. Smokeless tobacco
  6. Air pollution
  7. Exposure to infectious agents
  8. Suboptimal breastfeeding
  9. Occupational exposures

What are the preventable risk factors for cancer?

The most common preventable risk factor, however, was smoking tobacco. It is associated with 15 per cent of all cancer cases in a year. In men, the risk was significantly higher. Smoking contributed to 23 per cent of the new cancer cases globally in men that year. However, smoking alone was not the only cause; air pollution, depending upon the region, played a huge role. In East Asia itself, 15 per cent of lung cancer cases in women were attributed to air pollution. In Western Asia and Northern Africa, 20 per cent of lung cancer cases in men were due to air pollution.

After smoking tobacco, the next key lifestyle risk factor was drinking alcohol. It accounted for 3.2 per cent of all cancer cases—approximately 7 lakh. As per researchers’ estimates, drinking alcohol and smoking tobacco account for about 48 per cent of all preventable cancer cases. Infections, however, were associated with 10 per cent of new cancer cases. Among women, the largest share of these cases was attributed to high-risk human papillomavirus (HPV), which contributes to cervical cancer cases. However, with the HPV vaccine being more accessible, cervical cancer cases have reduced.

Can smoking give you stomach cancer?

Stomach cancer cases are higher among men and are mostly associated with inadequate sanitation, smoking, infections, and poor access to clean water. A first-of-its-kind analysis, this study helps show how much cancer risk comes from preventable causes. By examining these patterns, countries can be alerted to work towards preventing cancers in the first place by taking appropriate steps.

Researchers also mentioned in their paper that 4 in 10 cancer cases in the world in 2022 could have been prevented by eliminating the risk factors considered in the study. The study was published in the Nature Medicine journal.

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Sleeping Up To 7.8 Hours Can Help Slow Biological Aging

Updated May 26, 2026 | 07:00 AM IST

SummarySleep is an essential aspect of one's life, and it can impact one's biological age as well. A recent study claims that both less and more sleep can cause fast biological aging.
Sleeping Up To 7.8 Hours Can Help Slow Biological Aging

Credit: iStock

Sleep is a very crucial part of one's life, and it can affect one's life as a whole. The sleep cycle and duration can determine a lot about one's physical and emotional well-being. Even biological aging is also immensely affected by the right amount of sleep, according to a recent study. The aforementioned research was published in Nature, and as per it, getting too little or too much sleep may speed aging in the brain and other body organs as well.

There were several studies that have been done on the same topic, and many of them concluded that getting less sleep can cause the speeding of one's biological age. Although this new study has come up with a new finding, and it went further than the previous studies on the same topic, the research shows that getting more sleep can also lead you to the same situation, and your biological aging speed can go higher due to it.

The lead study author, Junhao Wen, PhD, assistant professor of radiological sciences at Columbia University, said, “Sleep is fundamental for healthy aging and longevity. More importantly, it is potentially modifiable." He added, “In this study, we measure biological aging clocks across organs to link these clocks with sleep duration.”

The biological age is inherently different from chronological age, which is measured by the number of years one is alive, but on the other hand, biological age measures how quickly your cells and tissues are aging. Researcher Junhao Wen has done his research with different aging clocks, and these clocks are scientific, computational models that estimate a person’s biological age and how they are aging faster or slower than their chronological age.

Wen and his colleagues assessed the relationship between a person’s self-reported sleep duration and their biological age, using 23 aging clocks across 17 organs. The research defined too little sleep as less than 6 hours and too much sleep as more than 8 hours. The study concludes that, in general, people who slept too little or too much showed signs of faster biological aging than those who reported sleeping between 6.4 and 7.8 hours each day.

The same study also sheds light on the relationship between sleep and chronic diseases. The research suggests that a connection exists beyond brain influence. Notably, less sleep causes disorders like depression and anxiety disorders. Other possible conditions related to it are obesity, type 2 diabetes, hypertension, ischemic heart disease, and heart arrhythmias. On the other hand, longer sleep is associated with depression and illness.

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Magic Mushroom: Study Claims Psilocybin Gives Relief From Pain?

Updated May 26, 2026 | 12:00 AM IST

SummaryMagic mushrooms are famous because of a compound that is naturally found in the fungus. The compound is called Psilocybin, which can reduce nerve pain very quickly and for a long duration with only one dose.
Magic Mushroom: Study Claims Psilocybin Gives Relief From Pain?

Photo Credit: iStock

Magic mushroom, a fascinating name, but the reason behind this naming is solely due to an active compound in that fungus called psilocybin. Notably, a single dose of it can easily reduce the nerve pain for months, thus has wide and effective use in painkillers according to a study recently done by the researchers from the University of Reading. This crucial study was published in Communications Biology.

The researchers used rats as test subjects to find this information. They injected psilocybin into mice with nerve damage. But within two hours, researchers found that the pain-relieving effect of psilocybin starts to relieve the pain in mice that had excruciating pain due to nerve damage. Though this was by no means the biggest finding of the study, it was also seen that the effect of the compound lasted for several weeks.

How Does Psilocybin Work As A Pain Reliever?

There is a very interesting explanation behind the long-lasting effect of Psilocybin. The active compound does not block the pain signal to the brain like other common pain relievers; instead, Psilocybin is likely to restructure the way the brain's pain-processing networks operate, which in turn ensures long-lasting effects of the compound even long after it exits the body.

What Is The Most Significant Finding Of The Study?

The study finds a great connection of mutual compatibility between psilocybin and gabapentin. Notably, gabapentin is a well-known drug commonly prescribed for nerve pain. In the aforementioned study, the researchers noticed that when gabapentin was given along with psilocybin, it produced pain relief lasting up to four days, but the effect when gabapentin was given alone was far weaker.

Dr Maria Maiarú, senior author from the University of Reading, said, "Millions of people live with nerve pain that their medication simply does not control well enough, and the medicines we do have can cause serious side effects or lead to addiction. What is exciting here is that psilocybin does not just reduce pain on its own. It appears to reset the brain's pain networks in a way that makes existing treatments significantly more effective. For patients who have run out of options, that could be genuinely transformative."

What Are The Other Crucial Findings In The Research?

Although initially the tests were done on the male mice, later on, the same compound was also injected into the bodies of female mice, and in both cases, the effect was complete success in achieving pain relief. The whole study was done with the aim of minimizing distress by using the 3Rs principles of Replacement, Reduction, and Refinement.

Why Is It called A Magic Mushroom?

The name is the direct result of its active compound, Psilocybin, which, when injected, can cause dream-like hallucinations, euphoria, and profound shifts in perception, mood, and consciousness.

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