The world that we live in is filled with sounds, some are comforting and some could be jarring too. But what if the constant noise surrounding us is doing us more harm than we realize? There has been immense research that shows that noise is not just a nuisance, but a silent killer and affects our health in ways we do not even know. There are associations of sound causing heart attacks, type 2 diabetes, and dementia.

How Does Your Body Respond To Noise?

Noise is seen as an annoyance, but it effects can go beyond what we imagine. When we hear a sound, it travels through the ear to the brain. This is where it gets processed by the amygdala. It is a region that is responsible for emotional responses. This also triggers a stress response- our heart rate increases, our blood pressure rises, and stress hormones like cortisol flood our system.

This response is also designed to help us react to immediate threats. Especially, if we hear the sound of a predator approaching. However, when we are exposed to constant noise, this response is triggered repeatedly and could compel us to live in a long-term anxious state.

Hidden Health Risks

Many studies including Harvard Health and theAmerican College of Cardiology have found associations of noise with health problems including putting a person at a higher risk of cardiovascular diseases such as heart strokes, attacks, and high blood pressure. The constant activation of the stress response can take a toll on the body, increasing inflammation and making it harder for the heart and circulatory system to function properly. Over time, this can lead to serious health conditions like heart disease and diabetes.

Even more troubling, research suggests that noise pollution may contribute to mental health issues. Studies have found a strong connection between exposure to noise and disturbed sleep, which in turn can cause anxiety, depression, and cognitive decline. The World Health Organization estimates that noise contributes to around 12,000 premature deaths annually across Europe alone. This invisible threat, however, is often overlooked because the effects are gradual and cumulative.

Noise and Sleep: A Silent Disturbance

One of the most insidious aspects of noise pollution is its impact on sleep. Even when we are asleep, our bodies are not fully immune to the effects of sound. Our ears never fully “turn off,” meaning that even faint noises can disrupt our sleep cycle. Research has shown that people who live in noisy environments—whether near busy roads, airports, or urban centers—often experience fragmented sleep, leading to fatigue and a weakened immune system. Over time, this chronic lack of restful sleep can lead to significant health problems, including an increased risk of developing cognitive disorders such as dementia.

The Urbanization Problem

As cities continue to grow, noise pollution is becoming more widespread. Traffic noise, in particular, is one of the most common and harmful sources. The rise of urbanization means more cars, buses, and trains, all of which contribute to an ever-increasing din. This urban soundscape is often relentless, with little respite for those living within it. In densely populated cities, people are exposed to high decibel levels, which can exceed safe thresholds for heart health. In many cases, the sheer volume of sound is not just unpleasant; it’s dangerous.

What Can We Do About It?

The solution is not as simple as reducing noise in our immediate surroundings, though efforts to reduce traffic noise and limit industrial sounds are essential. Some cities have taken steps to create quieter spaces by converting busy roads into pedestrian zones or installing noise barriers. These measures have shown to have a positive impact on public health, with research suggesting that even small reductions in noise can prevent premature deaths and improve overall well-being.

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.