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?

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.

Women who skip their first breast cancer screening may face a 40% greater risk of dying from the disease over the long term, according to a new study. The research, published in September in The BMJ, followed more than 400,000 women in Sweden over a span of up to 25 years.

When Should Women Begin Breast Cancer Screening?

The study raises important questions: at what age should women start screening, why does missing the first appointment increase long-term risk, and what other tests or self-checks might help? Dr. Leana Wen, an emergency physician and adjunct associate professor at George Washington University, weighed in on these points.

As per CNN, Wen explained that in the United States, breast cancer is the second most common cancer among women and the second leading cause of cancer death. In 2022, over 279,000 new cases were reported in women, and more than 42,000 women died from the disease in 2023.

Globally, a report from February, as per CNN, indicated that 1 in 20 women will develop breast cancer in their lifetime. Researchers estimate that by 2050, annual diagnoses could reach 3.2 million, with 1.1 million deaths worldwide.

When breast cancer is found and treated in its earliest stage, the five-year survival rate exceeds 99%, according to the American Cancer Society. Once cancer spreads to other organs, the survival rate drops to around 32%.

When Should Women Start Screening For Breast Cancer?

Last year, the U.S. Preventive Services Task Force recommended that most women begin mammograms at age 40 and continue every two years until age 74. Women over 75 should decide in consultation with their primary care provider.

For women at higher risk, screening may need to start earlier or occur more frequently. High-risk factors include prior chest radiation, certain genetic mutations, and having a first-degree relative, such as a mother or sister, with breast cancer.

The Swedish study tracked 432,775 women over up to 25 years. Nearly one-third of women invited for their first mammogram did not participate. Those who skipped the first screening were also less likely to attend future screenings and more likely to be diagnosed at advanced stages.

The study found that women who missed the initial mammogram were 1.5 times more likely to be diagnosed with stage 3 cancer and 3.6 times more likely for stage 4, compared to those who attended. After 25 years, death rates from breast cancer were significantly higher among the initial nonparticipants.

Researchers noted that while the findings reflect Sweden’s healthcare system, the principle that missing initial screenings increases long-term risk likely applies worldwide. An editorial in the same journal emphasized that attending the first mammogram is a long-term health investment, not just a routine check.

Why Does Delaying First Breast Cancer Screening Increase Long-Term Risk?

Wen highlighted that women who skip the first screening often continue to miss subsequent exams. Factors such as lack of awareness, access challenges, fear, and cultural influences may contribute. Late-stage diagnosis leads to lower survival rates and higher mortality.

Mammograms remain the standard screening tool for women at average risk. Higher-risk women may benefit from additional tests, such as genetic testing, breast MRI, or ultrasound. Women with dense breast tissue should discuss supplemental tests with their healthcare provider, as mammograms are less effective for detecting cancer in dense tissue.

What About Breast Self-Exams?

Self-exams are not a replacement for mammograms but can help women notice changes in their breasts. If a lump or other unusual symptoms appear—such as nipple discharge, pain, swelling, color changes, inward-turning nipple, enlarged lymph nodes, or skin changes—women should consult a healthcare provider immediately.

How Can Women Reduce Their Risk Of Breast Cancer?

Lifestyle factors play a major role. Smoking, excessive alcohol consumption, and obesity increase risk. Maintaining a healthy weight, staying physically active, eating a nutritious diet, quitting smoking, and moderating alcohol intake can all lower the risk and improve overall health.

We all indulge in tasty meals from time to time and with the holiday season approaching, many of us will be enjoying larger-than-usual meals. But going overboard can raise the risk of certain health problems, including heart attacks, especially for those with chronic health conditions.

“If you’re young and healthy, a single large meal is unlikely to trigger a heart attack, but for the right population, it can certainly increase the risk,” said Ameya Kulkarni, a cardiologist at Kaiser Permanente, as per The Washington Post.

Heart disease is the top cause of death in the United States, with someone experiencing a heart attack roughly every 40 seconds. That adds up to over 800,000 people annually, according to the CDC.

Heavy Meals Can Trigger Heart Risk

In 2000, a study abstract presented at an American Heart Association conference revealed that an “unusually heavy meal” may increase the risk of a heart attack by about four times in the two hours after eating, which the authors called the “hazard period” - particularly in those with pre-existing heart disease.

The participants described their meals as “heavy.” The abstract wasn’t published in a peer-reviewed journal.

Similarly, a 2005 analysis of 17 studies found that heavy physical activity, eating, and emotional stress were some of the common triggers reported before a heart attack. Men were more likely to report exertion and eating, while women often reported emotional stress.

Big Meals Stress The Heart

Eating a large, high-fat, high-calorie meal is similar to extreme physical exertion for your heart. To digest all that food, blood is redirected to your digestive system. Blood vessels tighten, heart rate and blood pressure rise, and blood flow to the heart can be limited, said Steve Kopecky, a cardiologist and professor at Mayo Clinic.

That spike in blood pressure can rupture cholesterol plaques in the arteries, forming clots. Even the fatty meal itself — think buttered potatoes, gravy, and heavily marbled meats — can make your blood more prone to clotting.

“These factors together can lead to a heart attack a few hours later,” Kopecky explained.

Who Is Most At Risk?

Certain conditions raise heart attack risk, including diabetes, high cholesterol, high blood pressure, and obesity, as well as lifestyle habits like poor diet, inactivity, or smoking history. For people with these risk factors, a large meal could act as a trigger, just like emotional stress or heavy physical activity, such as shoveling snow, said Kulkarni, also president of the AHA’s Greater Washington Region Board of Directors.

Heart Attack Warning Signs

• Chest pain or pressure in the center or left side of the chest that persists for several minutes or comes back.
• Pain or discomfort in one or both arms, jaw, neck, back, or above the stomach.
• Shortness of breath without physical activity.
• Weakness, dizziness, lightheadedness, or sudden cold sweats.
• Nausea or vomiting.
• Fast or irregular heartbeat.

Tips For Safer Indulgence

• Enjoy indulgent foods, but balance your plate with healthy options. Aim for half your plate to be fruits and vegetables, a quarter protein, and a quarter starch, Kulkarni said. Start with a salad, then add whole foods like turkey with a modest portion of stuffing, beans, or sweet potatoes.
• Eat slowly. It can take up to 20 minutes for your brain to register fullness, so eating quickly can lead to overeating. Treat meals as a social event and savor the time with family and friends.
• Limit alcohol. Drinking can increase appetite and reduce self-control, leading to eating more.
• Stop when you feel full. Skip that second helping once you’ve had enough.
• Take a walk after meals. Walking can help reduce triglycerides, regulate blood pressure, and lower blood sugar, Kopecky said.

Large meals high in saturated fats, calories, and processed carbs can increase heart attack risk for people with underlying health conditions. But with moderation, adding healthy foods to your plate, and skipping extra servings, you can enjoy your meals while lowering your risk.

Bird flu viruses pose a particular danger to people because they can continue multiplying even at temperatures that would normally stop most infections. Fever is one of the body’s natural ways to slow viruses, yet new research from the universities of Cambridge and Glasgow shows that avian strains can survive what should be a hostile environment.

The study, published in Science, identifies a key gene that influences how well a virus copes with heat. This same gene moved into human flu strains during the 1957 and 1968 pandemics, allowing those viruses to spread more easily.

How Flu Viruses Thrive In The Body

Human influenza viruses infect millions each year. The seasonal strains we see most often fall under influenza A and tend to do well in the cooler temperatures of the upper respiratory tract, which is close to 33°C. They are less suited to the warmer, deeper parts of the lungs, where temperatures reach about 37°C.

As per Science Daily, when the body cannot slow an infection, the virus continues to multiply and spread, which can lead to more serious illness. Fever acts as a protective response, pushing body temperature as high as 41°C. Until now, the exact reason why fever slows some viruses but not others has been unclear.

Avian influenza behaves differently. These viruses usually grow in the lower respiratory tract, and in their natural hosts, such as ducks or seagulls, they often infect the gut. Temperatures in these areas can reach 40°C to 42°C, which helps explain their greater tolerance to heat.

How Fever Limits Infection and Why Bird Flu Can Resist It

If left unchecked, a virus can move through the body and cause significant harm. Fever is one of the body’s most familiar defence responses and can raise the core temperature to levels that inhibit many pathogens. Scientists have long known that some viruses withstand these temperatures, but the reason behind this resistance has remained uncertain.

Avian flu strains show a clear advantage in hotter environments. They thrive in the lower airways and, in birds, survive in the high heat of the gut. These features distinguish them from human influenza strains, which prefer cooler tissue.

Earlier studies in cell cultures hinted that avian flu copes better with fever-range temperatures than human strains. The new research offers direct evidence from animal experiments, helping explain why fever is effective against some types of influenza but far less useful against others.

Experiments Show Why Fever Slows Human Flu but Not Avian Flu

Researchers from Cambridge and Glasgow recreated fever-like conditions in mice to examine how different viruses responded. They worked with a lab-adapted human influenza strain known as PR8, which does not pose a threat to people.

Mice do not typically develop a fever from influenza A, so the scientists raised the temperature of the environment to lift the animals’ body temperature.

The findings were striking. When body temperature rose to fever levels, the human-origin virus struggled to replicate, and the infection weakened. Avian influenza behaved very differently. Raising the temperature did not stop the virus from multiplying, and a small increase of only 2°C was enough to turn a normally severe human-origin infection into a mild one.

The PB1 Gene Helps Bird Flu Withstand Fever

The study also identified the PB1 gene as a major reason why bird flu can tolerate heat. PB1 helps the virus copy its genetic material inside infected cells. When viruses carried an avian-type PB1 gene, they were able to endure high temperatures and still cause severe disease in mice. This matters because avian and human flu viruses can exchange genes when they infect the same host, such as pigs.

Dr. Matt Turnbull, the study’s first author from the Medical Research Council Centre for Virus Research at the University of Glasgow, explained that this gene swapping remains a major concern for emerging influenza strains. He noted that similar exchanges occurred in 1957 and 1968, when human flu viruses replaced their PB1 gene with one from an avian strain. According to the researchers, this may help explain why those pandemics were so severe.