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

Semaglutide, Other GLP-1 Drugs Linked to Lower Colorectal Cancer Risk: Study

Updated Jun 23, 2026 | 09:01 PM IST

SummarySemaglutide reduced colorectal cancer risk among people with inflammatory bowel disease (IBD), as well as those with both IBD and type 2 diabetes.
Semaglutide, Other GLP-1 Drugs Linked to Lower Colorectal Cancer Risk: Study

Credit: iStock

GLP-1 receptor agonists (GLP-1 RAs), including semaglutide widely used to improve diabetes control and promote weight loss, may also reduce the risk of colorectal cancer, according to a new study.

The study found that the effect was particularly notable among people with inflammatory bowel disease (IBD), as well as those with both IBD and type 2 diabetes. Both conditions are associated with a higher risk of colorectal cancer due to chronic inflammation and metabolic changes that may promote tumor development.

"GLP-1 RA use was associated with a significantly reduced incidence of colorectal cancer in all patients with IBD, as well as the subpopulation with both IBD and type 2 diabetes," said lead author Sarina Ailawadi of Case Western Reserve University, US.

"Given the elevated colorectal cancer risk in IBD, these findings suggest a potential protective effect of GLP-1 RA use in this high-risk population. Prospective studies will be important to further analyze and confirm this potential benefit," she added.

The findings will be presented at the 2026 American Society of Clinical Oncology (ASCO) Breakthrough meeting, scheduled for June 25–27 in Singapore.

Also read: Robert F. Kennedy Jr. Launches Reforms To Speed Up Early Drug Research In US

How Was The Study Conducted?

This retrospective cohort study analyzed data from 69,221 people in the US, including GLP-1 RA users and non-users.

Researchers also identified 209,649 people with both IBD and type 2 diabetes, including 38,567 who had taken a GLP-1 RA.

After matching users and non-users for various characteristics, data from 37,740 patients were analyzed. The GLP-1 RA group included people taking semaglutide, dulaglutide, tirzepatide, exenatide, liraglutide, or lixisenatide.

The researchers compared the five-year incidence of colorectal cancer between GLP-1 RA users and non-users.

Among people with IBD, the five-year incidence of colorectal cancer was 0.2% in GLP-1 RA users compared with 0.42% in non-users. The odds ratio was 0.49, indicating a 51% lower likelihood of developing colorectal cancer among GLP-1 RA users.

Among patients with both IBD and type 2 diabetes, the five-year incidence of colorectal cancer was 0.31% in GLP-1 RA users and 0.57% in non-users. The odds ratio was 0.54, suggesting a 46% lower likelihood of developing colorectal cancer.

The researchers noted that prospective studies are needed to confirm the potential protective effect of GLP-1 RAs on colorectal cancer risk.

Do IBD and Type 2 Diabetes Increase Colorectal Cancer Risk?

Read More: Natural Origin or Lab Leak? Gabbard Reignites COVID Origins Debate, Claims Fauci Funded Wuhan Lab Research

Inflammatory bowel disease is associated with a higher risk of colorectal cancer, likely because of chronic inflammation in the intestines. People with IBD are estimated to be six times more likely to develop colorectal cancer than those without the condition.

Type 2 diabetes, the most common form of diabetes, also increases colorectal cancer risk and is becoming more common among people with IBD. Scientists believe that individuals with both conditions may face an especially high risk because of the combined effects of chronic inflammation and metabolic dysfunction.

What Are GLP-1 Receptor Agonists?

GLP-1 receptor agonists are a class of drugs that help lower blood sugar levels and promote weight loss. Originally developed to treat type 2 diabetes, many are now widely used for weight management.

These medications mimic the action of the GLP-1 hormone by stimulating insulin release, slowing digestion, and increasing feelings of fullness.

Beyond blood sugar control and weight loss, GLP-1 RAs have been linked to several health benefits, including lower blood pressure and reduced cardiovascular risk. Previous studies have also suggested that they may lower the risk of colorectal cancer and other obesity-related cancers.

However, their specific impact on colorectal cancer risk among people with IBD has remained unclear until now.

End of Article

Raising Sons Linked to Faster Cognitive Decline in Later Life, Study Find

Updated Jun 23, 2026 | 10:00 PM IST

SummaryA study of over 13,000 parents found those with sons experienced faster cognitive decline than parents of only daughters, suggesting long-term caregiving and social support—not biology—may influence brain aging.
Raising Sons Linked to Faster Cognitive Decline in Later Life, Study Find

Credit: AI Generated Image

A new study involving more than 13,000 parents suggests that parents who have sons may experience faster cognitive decline in later life compared to parents who only have daughters. While the findings may sound surprising, researchers stress that the results are linked to long-term caregiving and social support—not biology.

The research, published in the Journal of Psychiatric Research, explored how family composition might affect cognitive health as people grow older.

What Did The Study Find?

Researchers from Columbia University and Charles University analyzed data from 13,222 adults aged 50 and above who participated in the US Health and Retirement Study.

The team discovered several important patterns:

Parents with at least one son showed a faster rate of cognitive decline than parents who had only daughters.

The association was observed in both mothers and fathers, suggesting the effect is driven by social and caregiving factors rather than biological differences.

Parents with multiple sons experienced an even steeper decline in cognitive function over time compared to parents whose children were all daughters.

The researchers concluded that having sons was associated with a faster decline in memory and thinking abilities during older adulthood.

Why Might Daughters Make A Difference?

The researchers believe the explanation lies in family dynamics rather than genetics.

Previous studies have consistently shown that daughters are more likely to provide emotional support, regular communication, and hands-on caregiving as their parents age. This ongoing engagement may help keep parents mentally active and socially connected—two factors that are strongly associated with healthier brain aging.

Experts often refer to this as the "daughter effect." Strong emotional bonds and frequent social interactions are known to protect cognitive function and may reduce the risk of age-related mental decline.

How Was Cognitive Health Measured?

Participants' cognitive abilities were evaluated every two years using several standard mental performance tests, including:

  • Immediate and delayed word recall tests
  • Serial subtraction exercises
  • Backward counting tasks

These assessments allowed researchers to track changes in memory, attention, and problem-solving skills over several years.

Even after adjusting for factors such as age, education, health status, and socioeconomic background, the relationship between having sons and faster cognitive decline remained significant.

Previous Research Supports Similar Findings:

The study also builds on earlier research that linked having more sons with poorer long-term maternal health outcomes, including an increased risk of dementia.

By examining both mothers and fathers, the new research suggests the relationship extends beyond pregnancy-related biological factors and is more likely connected to differences in caregiving and emotional support provided by adult children.

Also Read: UK Met Office Warns of 'Pollen Bomb': What Hay Fever Patients Need to Know

What Does This Mean For Families?

The findings should not be interpreted as a reason to worry about having sons. Instead, they highlight the importance of maintaining strong family relationships, staying socially active, and ensuring older adults receive emotional and practical support regardless of their children's gender.

Researchers say that healthy aging depends on many interconnected factors, and supportive relationships can play an important role in preserving cognitive function over time.

The study suggests that parents with sons may experience faster cognitive decline than parents with only daughters, with the effect becoming stronger as the number of sons increases. However, experts caution that family composition is just one small piece of the puzzle. Healthy lifestyle habits, social connections, education, and quality caregiving remain the most important factors for maintaining brain health throughout aging.

End of Article

Madonna Reveals 'Bad Knee' with 'No Cartilage' After Years of Dancing in Heels and Ashtanga Yoga

Updated Jun 23, 2026 | 06:00 PM IST

Summary​​The 67-year-old superstar said running and Ashtanga yoga also added stress to her joints, leaving her with “no cartilage” in her knee, according to Interview Magazine.
Madonna Reveals 'Bad Knee' with 'No Cartilage' After Years of Dancing in Heels and Ashtanga Yoga

Credit: Instagram

Pop singer Madonna has opened up about knee damage caused by years of dancing in high heels.

The 67-year-old superstar said running and Ashtanga yoga also added stress to her joints, leaving her with “no cartilage” in her knee, according to Interview Magazine.

“I have a bad knee now. I have no cartilage in it, thanks to dancing for so long in high heels and running on pavement and doing Ashtanga yoga,” Madonna told the magazine.

“Up until a year ago, I was jumping on trampolines and doing dance cardio and doing a lot of what a doctor would call loading on my joints. Can’t do that anymore,” she added.

Madonna said she still works out regularly while listening to her new album Confessions II, but has had to modify her fitness routine to accommodate the injury.

The Queen of Pop said she now focuses on “Peloton bikes and the Versa Climber and high-intensity circuit training. I ride my bike outside a lot. I dance.”

Madonna has previously been open about her knee injury and its impact on her career. In October 2019, she postponed a scheduled Madame X show in Brooklyn, New York.

“It's Hard for Madame to admit that she is also a human being made of flesh and blood and she must rest for the next 3 days to insure full recovery for her knee,” she wrote on Instagram.

“I am not a quitter. This hurts me more than you can imagine. It's time to take those heels and fishnets off for a few days!”

Also read: Marketa Vondrousova Banned For 4 Years From Tennis: How Doping Tests Work

Can High Heels Affect Knee Health?

Knee osteoarthritis (OA), a leading cause of disability, is more prevalent in women than men. Wearing high-heeled shoes has been implicated as a potential contributing factor to the higher lifetime risk of osteoarthritis in women.

Several studies have examined the relationship between high heels and knee health. Motion analysis studies have shown changes in knee alignment while walking in heels, changes that researchers have suggested may resemble patterns seen in ageing and knee osteoarthritis progression.

Read More: UK Met Office Warns of 'Pollen Bomb': What Hay Fever Patients Need to Know

A 2025 study published in The Knee by researchers from the Singapore Institute of Technology found that wearing 8-cm high-heeled shoes significantly reduced the lateral joint space width of the knee in healthy young women during standing, suggesting increased lateral knee joint stress.

The findings suggest that high heels may specifically affect the lateral compartment of the knee, potentially contributing to increased joint stress during standing.

Wearing heels for long periods can increase the load on the knees. They alter posture and walking patterns, placing additional pressure on the knee joint. Over time, this may strain the ligaments and muscles surrounding the knee, leading to pain, stiffness, and long-term damage.

In 2025, the Nicki Minaj Challenge, inspired by the rapper's 2013 song High School, gained traction on social media. The challenge, which involved balancing in high heels, reportedly resulted in injuries including fractures and, in some cases, deaths.

End of Article