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.

End of Article

Teen Reproductive Health Problems May Be Linked To GI, Mental Health & Chronic Pain In Adulthood: Lancet

Updated Oct 9, 2026 | 12:00 AM IST

SummaryA recent study published in The Lancet Regional Health – Americas found that reproductive problems during teenage years could cause pelvic pain and other health conditions decades later.
Pelvic Pain In Adulthood May Be Linked To Teen Reproductive Health Problems: Lancet

Credit: AI

Chronic pelvic pain in adulthood may have warning signs that appear much earlier in life. A new study suggested that reproductive and gynecological health problems during adolescence could identify people at higher risk years before chronic pain develops.

The study, carried by The Lancet Regional Health – Americas, analysed health data of nearly half a million people in Ontario, Canada, following them from adolescence into adulthood.

The researchers found that after 10 years into adulthood, chronic pelvic pain affected 28% of people who had sought healthcare for gynecological or reproductive health problems during their teenage years, compared to about 15% among those without such health issues during adolescence.

In a nutshell, the rate of chronic pelvic pain was 41% higher among people who had earlier gynecological or clinical visits due to reproductive issues.

Findings Just Not Restricted To Pelvic Pain

Also read: High BP in Pregnancy Linked to 42,000 Maternal Deaths, 500,000+ Stillbirths, Newborn Deaths: WHO

The researchers used population-based health data held by ICES and followed people from adolescence into adulthood. The analysis also considered other health problems and healthcare use during adolescence.

The findings also indicated that teenagers who had sought care for gynecological or reproductive problems were also more likely to have gastrointestinal problems, mental health conditions and chronic pain in other parts of the body.

“We asked a simple question: Were there signs, years earlier, that someone was on a path toward chronic pelvic pain? This study shows that indeed, the gap between those affected by CPP was already visible early in adulthood and grew over time,” said lead author Shay Freger, a PhD candidate in McMaster University's Department of Obstetrics and Gynecology.

What Is Chronic Pelvic Pain?

Also read: Childhood Fitness Linked To Lower Risk Of Depression In Adulthood: 30-Year Study

Chronic pelvic pain refers to persistent pain in the lower abdomen or pelvic region that can continue for months or years.

It can affect everyday life, education, work, relationships and mental health. Researchers also identified that pelvic and menstrual symptoms during adolescence can sometimes be dismissed as a normal part of growing up, even when the pain is severe or persistent. This could discourage a person to seek medical help.

The findings suggest that these symptoms could offer doctors and healthcare experts a key opportunity to identify patterns of certain health conditions earlier in life.

“What is important about this study is that the warning signs were not limited to reproductive health alone,” said Mathew Leonardi, senior author and associate professor in McMaster’s Department of Obstetrics and Gynecology.

“It suggests that adolescent menstrual and pelvic health may be part of a broader health picture that deserves earlier attention and more integrated care.”

Not A Cause-And-Effect Relationship

The study just noticed an association, but it does not establish that adolescent gynecological or reproductive problems are the direct reasons behind chronic pelvic pain decades later in life.

Instead, the researchers say the findings indicate that healthcare providers may already be seeing patterns during adolescence that could be linked with greater vulnerability to chronic pain and other disorders in adulthood.

The researchers also said that recognising these patterns earlier could help shift pelvic pain care from treating to identifying and addressing problems before they become persistent.

End of Article

Delhi Smog: Can You Really Tackle Pollution Season With An N95 Mask And Air Purifier?

Updated Oct 8, 2026 | 10:00 PM IST

SummaryN95 masks and air purifiers usually are the common man's first line of defence against pollution season in Delhi. But neither can offer complete protection from particulate matter.
Delhi Smog: Can You Really Tackle Pollution Season With An N95 Mask And Air Purifier?

Credit: AI

As pollution season creeps back in Delhi, N95 masks outdoors and air purifiers are once again most likely to become the primary go-to protective measures for the public.

Both are known to lower exposure to harmful particles significantly, but neither can completely nullify the health risks of polluted air. So before you invest in an air purifier or buy a dozen N95 masks, understand how much you will be protected as you step out during smog everyday.

How Much Protection Does An N95 Mask Offer?

Also read: Delhi Pollution: What Are The Different Types Of Anti-Pollution Masks?

A properly fitted N95 respirator can filter at least 95% of airborne particles under standard environment. That makes it substantially more protective against fine particulate matter like PM2.5 than regular surgical or cloth masks.

But just wearing an N95 does not mean you are breathing toxins-free air. Its effectiveness depends heavily on fit. Gaps around the nose, cheeks or chin can let polluted air to bypass the filter.

An N95 also does not protect equally against every pollutant. It is designed primarily to filter particles, not gases like nitrogen dioxide or ozone. So if you spend most of your time outdoors during severe pollution, wear a well-fitted, certified respirator to reduce exposure.

Protection from PM2.5 is key as these particles are small enough to seep deep into your lungs and, in some circumstances, even cross over to enter the bloodstream. Long-term exposure to PM2.5 has been associated with cardiovascular disease, respiratory disease and other serious health problems.

Is An Indoor Air Purifier Enough To Tackle Outdoor Pollution?

The effectiveness of an air purifier depends significantly on the purifier, the size of the room and how it is used. A purifier equipped with a HEPA filter can remove fine particles from indoor air. When outdoor PM2.5 levels are high and polluted air enters homes through windows, doors and ventilation systems, this could be one of the best ways to protect yourself.

However, simply switching on a purifier in a large room does not guarantee clean air. The purifier needs to have sufficient clean air delivery rate (CADR) for the size of the room.

Keeping doors and windows closed during periods of extreme outdoor pollution can also help reduce the amount of polluted air entering. Filters need to be replaced according to the manufacturer's recommendations because a heavily loaded filter can reduce performance.

Also read: Delhi Air Pollution Is Back: What Days Of Poor AQI Can Do to Your Lungs

One of the limitations is that HEPA filtration primarily addresses particles. A purifier needs additional technologies, like an activated-carbon filter, to reduce some gaseous pollutants, and even then it cannot remove every pollutant completely.

For Delhi's pollution season, these two measures address different exposure issues. N95 masks help reduce inhalation of polluted particles while outdoors. Air purifiers help lower indoor concentrations of particulate matter. Using both can therefore provide greater protection than relying on either measure alone.

People with asthma, COPD, heart disease or other respiratory and cardiovascular conditions, as well as children and older adults, can be more vulnerable to the effects of air pollution.

Even healthy people can experience symptoms like coughing, throat irritation, wheezing, eye irritation and breathing discomfort when pollution levels rise.

End of Article

Can Creatine Help You Hold On to Muscle As You Age?

Updated Oct 9, 2026 | 02:00 AM IST

SummaryMuscle mass naturally declines with age, but a new 12-week study suggests creatine may help older adults gain lean tissue and strength, even without structured exercise. But more research is needed.
Creatine May Help Preserve Muscle With Age

New research suggests creatine may help older adults gain lean tissue and strength as they age.

Getting older changes what your body is made of. Fat tends to build up while muscle shrinks.

Now Texas A&M University researchers say creatine, a popular supplement, may help. In a 12-week study, adults aged 45 to 65 who took it gained lean tissue and strength, even without a structured exercise plan. But the study is small.

What The Study Found

The paper appeared in the Journal of the International Society of Sports Nutrition in August 2026.

Also Read: XFG COVID Variant: What India Should Watch As Cases Rise In UK And France

The researchers, led by principal investigator Richard Kreider, who directs Texas A&M's Exercise and Sport Nutrition Lab, said the 64 healthy adults finished the 12-week study. Each chose whether to join a supervised exercise and diet program. Then, within each group, they were randomly given either 10 grams of creatine a day or a placebo, a look-alike powder with no creatine. The participants did not knew which powder they were getting.

Among those who did not exercise, the creatine group gained about 2.4 pounds of lean tissue, the researchers said. They also got stronger in the leg press and bench press.

Those in the exercise program saw bigger gains with creatine than with a placebo in leg press, bench press and time to exhaustion, which is how long they could keep going before having to stop. Aerobic capacity did not seem to improve.

Keeping muscle while losing weight

Losing weight often means losing muscle too. In the exercise group, people ate a diet with a small calorie cut. After 12 weeks, those on creatine had gained nearly three pounds of lean tissue and lost fat, the researchers said.

Those on a placebo showed little change in lean tissue. The researchers say creatine also cut body fat percentage more, which they believe is a first.

What Is Creatine?

Creatine is a chemical compound found naturally in the body and in several foods including meat, fish, and protein-rich plant-based sources like tofu, tempeh, beans, lentils, and nuts.

Despite its natural occurrence and widespread use, especially among fitness enthusiasts, there is a growing body of evidence casting doubt on its effectiveness when used as a standalone enhancer for muscle growth.

What To Keep In Mind

Only 64 people finished the study. The researchers cautioned that because people chose their own exercise group, the groups may have differed in other ways. The study used 10 grams a day, while the paper describes 3 to 5 grams as a common long-term dose. Kreider says many people do not get enough creatine from food, according to Texas A&M. He says you would need five to 10 pounds of meat or fish a day to reach 10 grams.

So the takeaway is simple. Creatine looks promising for holding on to lean tissue with age, but one small study is not the last word.

End of Article