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.

People with blood type B, either positive or negative, are 28 percent more likely to develop Type 2 diabetes, according to a 2024 BMC Medicine study.

Human blood is categorized into eight main groups based on the sugars and proteins, or lack thereof, present on the surface of your red blood cells.

A, B, and AB types are based on the presence of antigens, sugar molecules that can trigger an immune response. O-type blood has no A or B antigens. Meanwhile, Rhesus (Rh) factors are proteins that determine blood compatibility and give your blood its positive or negative designation.

According to a group of Chinese researchers, who conducted a thorough umbrella review of 270 studies, the strongest link between a blood group and Type 2 diabetes was between those with a B blood group.

The researchers also didn't examine what might drive this increased risk. A 2025 study suggests that the gut microbiome may be involved; however, further investigation is needed.

However, the results do suggest that there's a real, tangible association between blood type and Type 2 diabetes – one that people can factor into how they think about their own risk.

What is Type 2 Diabetes?

Type 2 diabetes (T2D) occurs when blood sugar (glucose) remains consistently high. Normal blood sugar levels fall between 70 and 99 milligrams per deciliter (mg/dL). If undiagnosed, Type 2 diabetes often shows levels of 126 mg/dL or more.

T2D happens because the pancreas doesn’t produce enough insulin, the body can’t use insulin effectively, or a combination of both. This differs from Type 1 diabetes, which arises when the immune system attacks the pancreas, leaving the body unable to produce insulin at all.

How Common Is Type 2 Diabetes?

Type 2 diabetes is widespread. Over 37 million people in the US have diabetes (around 1 in 10), with 90–95 percent of cases being T2D. Globally, it affects roughly 6.3 percent of the population. While it’s most common in adults over 45, younger adults and even children can develop it.

Blood Sugar Range For Adults And Children With Type 2 Diabetes

The American Diabetes Association recommends the following ranges for adults with type 1 or type 2 diabetes and children with type 2 diabetes:

Recommended Blood Sugar Range

Fasting (before eating): 80 to 130 mg/dL

1 to 2 hours after meal: Lower than 180 mg/dL

Is Type 2 Diabetes Genetic?

T2D has complex causes, but genes play a significant role. If one biological parent has T2D, your lifetime risk is around 40 percent, and if both parents do, it rises to 70%. Scientists have identified over 150 DNA variations linked to T2D risk, some increase the chance of insulin resistance or reduced insulin production, while others influence obesity risk. These genetic factors interact with lifestyle and health habits to determine overall risk.

How is Type 2 Diabetes Diagnosed?

Doctors use several blood tests to confirm T2D:

• Fasting plasma glucose test: Measures blood sugar after an eight-hour fast. A result of 126 mg/dL or higher indicates diabetes.
• Random plasma glucose test: Measures blood sugar at any time without fasting. A reading of 200 mg/dL or higher signals diabetes.
• A1C test: Reflects average blood sugar over the past 2–3 months. A level of 6.5% or higher indicates diabetes.

Scientists have found a new potential way to treat Alzheimer’s disease and it's already approved by the US Food and Drug Administration.

Researchers at the the Indiana University School of Medicine have found that removing or reducing a specific brain cell enzyme, known as IDOL, can significantly lower the buildup of amyloid plaques while also helping the brain resist further damage.

As of now, Lecanemab and Donanemab drugs can help achieve this as they work by clearing these plaques from the brain and can help slow the progression of symptoms.

However, the researchers' new theory focuses on preventing plaque buildup in the first place, while also improving how brain cells communicate and process fats.

The scientists claim that enzymes such as IDOL are easier to target with drugs due to their well-defined structures, allowing them to design treatments that are more precise and potentially have fewer side effects.

Kim, the P. Michael Conneally Professor of Medical and Molecular Genetics: "What makes this exciting is that we now have a specific target that could lead to a new type of treatment.

"We believe that IDOL will provide us with an alternative strategy to treat Alzheimer’s disease. Targeting enzymes in drug development offers key advantages due to their well-defined active sites or ‘pockets’ where drugs can attach and block their activity. This precision means we can design molecules that hit the right target with minimal side effects."

Kim notes that the team now plans to explore several approaches to target IDOL as part of new Alzheimer’s treatments including testing the safety and effectiveness of potential compounds in preclinical models.

The researchers will also study whether blocking IDOL can help preserve synaptic connections and reduce tau pathology, another key feature of the disease.

READ MORE: The One Critical Thing You Should Do To Prevent Alzheimer's Disease

What Is Alzheimer’s Disease?

Alzheimer's disease is one of the most common forms of dementia and mostly affects adults over the age of 65.

About 8.8 million Indians aged 60 and above are estimated to be living with Alzheimer's disease. Over seven million people in the US 65 and older live with the condition and over 100,00 die from it annually.

Alzheimer's disease is believed to be caused by the development of toxic amyloid and beta proteins in the brain, which can accumulate in the brain and damage cells responsible for memory.

Amyloid protein molecules stick together in brain cells, forming clumps called plaques. At the same time, tau proteins twist together in fiber-like strands called tangles. The plaques and tangles block the brain's neurons from sending electrical and chemical signals back and forth.

Over time, this disruption causes permanent damage in the brain that leads to Alzheimer's disease and dementia, causing patients to lose their ability to speak, care for themselves or even respond to the world around them.

While there is no clear cause of Alzheimer's disease, experts believe it can develop due to genetic mutations and lifestyle choices, such as physical inactivity, unhealthy diet and social isolation.

Early symptoms of Alzheimer's disease include forgetting recent events or conversations. Over time, Alzheimer's disease leads to serious memory loss and affects a person's ability to do everyday tasks.

There is no cure for this progressive brain disorder and in advanced stages, loss of brain function can cause dehydration, poor nutrition or infection. These complications can result in death.

Can You Detect Alzheimer's Early On?

The US Food and Drug Administration has approved the use of a blood test which can help diagnose Alzheimer’s disease in adults aged 55 and above.

The blood test, known as Lumipulse, can detect amyloid plaques associated with Alzheimer’s disease and has proven to be a “less invasive option” that “reduces reliance on PET scans and increases diagnosis accessibility.”

FDA Commissioner Martin A. Makary said of the landmark decision, "Alzheimer’s disease impacts too many people, more than breast cancer and prostate cancer combined.

"Knowing that 10 percent of people aged 65 and older have Alzheimer's, and that by 2050 that number is expected to double, I am hopeful that new medical products such as this one will help patients."

It remains unclear when this test will be available for commercial use across the world.

Adults aged 65 and older who completed five to six weeks of cognitive speed training, known as speed of processing training, are less likely to develop dementia over 20 years, according to a Alzheimer’s & Dementia: Translational Research and Clinical Interventions study.

In this NIH-funded study, researchers examined 2,802 adults from 1998–99 and compared three types of cognitive training including memory, reasoning, and speed of processing.

Participants in the training groups completed up to 10 sessions lasting 60 to 75 minutes over five to six weeks. About half also received up to four additional booster sessions at 11 and 35 months after the initial training.

After 20 years, 40 percent of participants in the speed training group who received boosters were diagnosed with dementia, compared to 49 percent in the control group. This represents a 25 percent lower risk and was the only intervention that showed a statistically meaningful difference.

Marilyn Albert, Ph.D., the corresponding study author and director of the Alzheimer’s Disease Research Center at Johns Hopkins Medicine: "Seeing that boosted speed training was linked to lower dementia risk two decades later is remarkable because it suggests that a fairly modest nonpharmacological intervention can have long-term effects.

"Even small delays in the onset of dementia may have a large impact on public health and help reduce rising health care costs."

Albert explained that additional studies are needed to understand underlying mechanisms that may help explain these associations and to understand why the reasoning and memory interventions didn’t have the same 20-year associations

READ MORE: High Brain Age May Increase Dementia Risk, Study Shows

What Is Dementia?

Dementia is an umbrella term used to describe a significant decline in mental function that is serious enough to affect everyday life. It commonly impacts memory, thinking, and reasoning skills.

Dementia itself is not a single disease but a collection of symptoms caused by underlying conditions such as Alzheimer’s disease or vascular dementia.

Common signs include memory problems, confusion, difficulty finding words, changes in mood or behaviour and trouble completing familiar tasks.

These symptoms usually worsen over time and are not considered a normal part of ageing. Although there is no cure, treatment options can help manage symptoms, and early diagnosis plays an important role in care planning.

Alzheimer’s Disease: The Leading Cause of Dementia

Alzheimer's disease is one of the most common forms of dementia and mostly affects adults over the age of 65.

About 8.8 million Indians aged 60 and above are estimated to be living with Alzheimer's disease. Over seven million people in the US 65 and older live with the condition and over 100,00 die from it annually.

Alzheimer's disease is believed to be caused by the development of toxic amyloid and beta proteins in the brain, which can accumulate in the brain and damage cells responsible for memory.

Amyloid protein molecules stick together in brain cells, forming clumps called plaques. At the same time, tau proteins twist together in fiber-like strands called tangles. The plaques and tangles block the brain's neurons from sending electrical and chemical signals back and forth.

Over time, this disruption causes permanent damage in the brain that leads to Alzheimer's disease and dementia, causing patients to lose their ability to speak, care for themselves or even respond to the world around them.

While there is no clear cause of Alzheimer's disease, experts believe it can develop due to genetic mutations and lifestyle choices, such as physical inactivity, unhealthy diet and social isolation.

Early symptoms of Alzheimer's disease include forgetting recent events or conversations. Over time, Alzheimer's disease leads to serious memory loss and affects a person's ability to do everyday tasks.

There is no cure for this progressive brain disorder and in advanced stages, loss of brain function can cause dehydration, poor nutrition or infection. These complications can result in death.