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.

Alzheimer’s disease and dementia are often viewed as diseases of old age, with memory loss considered one of their most recognizable symptoms. However, emerging research increasingly points to factors such as diabetes, blood pressure, hormonal changes and lifestyle during midlife, particularly from the 40s onward, that may influence the risk of cognitive decline later in life.

As ageing populations worldwide face a growing dementia burden, doctors are emphasizing the importance of identifying and addressing these risks in midlife. Alzheimer’s disease is a progressive brain disorder that affects memory, thinking and the ability to manage everyday life.

HealthandMe spoke to doctors about the disproportionate burden of Alzheimer’s among women, the link between diabetes and accelerated brain ageing, and how disease-modifying treatments such as lecanemab are changing the treatment landscape. They also highlighted the importance of early assessment to identify cognitive problems that families may otherwise dismiss as normal ageing.

Diabetes And The Ageing Brain: The Quiet Connection

Type 2 diabetes is an important modifiable factor associated with accelerated brain ageing, making cognitive health an important part of diabetes care.

Dr. V. Mohan, Managing Director, Dr Mohan’s Diabetes Specialities Centre and President, Madras Diabetes Research Foundation, told HealthandMe that every diabetes appointment follows a familiar rhythm: check blood sugar, examine the feet, check the eyes, review the heart and kidneys, and renew the prescription. But the brain, more often than not, receives little attention.

Research suggests that type 2 diabetes is associated with accelerated brain ageing, while vascular damage linked to high blood sugar, blood pressure and cholesterol can affect the brain as well as the heart, kidneys and eyes.

The 2024 Lancet Commission on dementia prevention, intervention and care identified diabetes as one of 14 modifiable risk factors associated with nearly half of dementia cases worldwide.

“The message is simple: just as people routinely check their blood pressure, blood sugar, eyes, feet and kidneys, cognitive health deserves attention too,” he said, while suggesting ABCD for Protecting Brain Health in Diabetes:

A – Aim for HbA1c Control

B – Blood Pressure Control

C – Control Cholesterol

D – Diet Management

Why Menopause Matters For Women’s Brain Health

Women carry a disproportionate burden of Alzheimer’s disease. According to Stanford, roughly three women are diagnosed with Alzheimer’s for every two men, while data from the Framingham Heart Study cited by the

Alzheimer’s Association estimated that at age 45, the lifetime risk of developing clinical Alzheimer’s dementia was about 20% for women compared with 10% for men.

Dr. Anmol Singh Rai, Consultant Neurology, Fortis Hospital Jalandhar, pointed out several factors that may contribute to this difference. He noted:

• APOE4 is one important factor. In women, the gene variant has been associated with a greater increase in dementia risk than in men.
• Age is another major factor, with dementia risk rising sharply in older age groups. Since women generally live longer, more women reach the ages when dementia becomes increasingly common.
• Hormonal changes may also play a role. Declining estrogen during menopause can affect brain metabolism and neuronal health, making the menopausal transition an important period for paying attention to cognitive and overall health.

“Managing blood pressure, blood sugar and cholesterol, addressing hearing loss, identifying sleep apnea, staying physically active and addressing depression and social isolation can all form part of a broader approach to brain health,” he told HealthandMe.

Alzheimer’s: Why Early Detection Matters As Treatment Advances

More than 55 million people worldwide live with dementia today, with a new case developing every three seconds. This number is projected to rise to 139 million by 2050.

With the arrival of disease-modifying treatments such as Leqembi (lecanemab), the importance of identifying cognitive decline early has become even greater.

"For three decades, Alzheimer's treatment has leaned on drugs that modestly improve cognition, function and behavior, buying patients and caregivers meaningful time. But none of them alter the underlying biology of the disease," Dr. Praveen Gupta, Chairman, Marengo Asia International Institute for Neuro and Spine (MAIINS), Marengo Asia Hospitals, Gurugram, told HealthandMe.

The disease-modifying therapy for Alzheimer’s, Leqembi, was cleared in the US in 2023, followed by Japan the same year, China in June 2024, the European Union in 2025, and India in August 2026.

"Unlike everything that came before it, lecanemab is designed to act on the pathological process itself, not merely its downstream consequences," Dr. Praveen Gupta said.

However, the treatment is not meant for everyone with Alzheimer’s. It is approved for early Alzheimer’s disease, including mild cognitive impairment and mild dementia, rather than moderate or advanced disease.

That makes timely diagnosis particularly important.

"Patient selection now hinges on confirming amyloid pathology, through cerebrospinal fluid analysis or blood-based biomarkers, before treatment even begins," Dr. Praveen Gupta explained.

Brain Health Should Begin Before Memory Loss

The experts noted that brain health is not something that needs attention only after memory loss begins.

Midlife is an important window to control blood pressure, blood sugar and cholesterol, remain physically active, address hearing and sleep problems, and pay attention to changes in memory or thinking.

For people already showing cognitive symptoms, early medical assessment can help distinguish normal ageing from mild cognitive impairment, dementia or potentially treatable conditions.

Cardiac arrest is considered one of the most urgent medical situations. It can occur unpredictably, at home, at work, while traveling, or anywhere. It is characterized by a blockage in the heart's arteries, and it differs from a heart attack, which is a situation when the heart stops pumping blood into the body. After a few minutes, oxygen deficiency happens and affects the brain and other organs. Therefore, it is important to know how to perform cardiopulmonary resuscitation (CPR).

CPR is an emergency lifesaving technique that uses chest compressions and, in some situations, blowing mouth-to-mouth air into the person who has suffered a cardiac arrest, to help maintain blood circulation and oxygen delivery to vital organs when a person's heart has stopped beating effectively. It does not restart the heart by itself, but it can keep blood flowing until an automated external defibrillator (AED) is available or emergency medical professionals arrive.

Importantly, CPR is not a skill limited to doctors or healthcare professionals. It can be administered by ordinary people for whom learning the basic CPR techniques is easy.

The Importance of Rapid and Efficient Actions in Case of Cardiac Arrest

If someone faces cardiac arrest, rapid actions may save this person's life. If CPR is performed directly and immediately after a cardiac arrest, it will be possible to keep the flow of blood to the brain and other organs before the arrival of medical experts. The use of CPR can improve the chances of survival for patients who have experienced cardiac arrest.

Besides, in combination with early defibrillation through an AED, it can be even more effective. AED is a portable medical device that checks the heart rhythm of the person experiencing cardiac arrest and delivers an electric shock to restart a normal heartbeat.

However, sometimes people prefer to do nothing for fear of mistakes. But it is much more dangerous not to act at all.

Recognizing Cardiac Arrest

It begins with identifying the presence of a possible cardiac arrest in the patient. The patient will generally fall, become unconscious, and will not breathe properly. They can occasionally breathe abnormally with strange sounds, which should not be considered breathing properly.

If you see anyone fall and become unresponsive, check whether they respond to your questions and breathe normally. Tell any passerby to call the emergency services and bring an AED device, if one is present. If the patient is not breathing normally, initiate CPR on them.

What To Do?

If the patient is an adult, hands-only CPR can be done easily by everyone. For this, you need to keep the heel of one of your hands in the center of the person’s chest, keep your other hand over it, and press down with a rapid rhythm. The compression must be continued at a pace of around 100-120 beats per minute.

Also, you can use the AED device if one is available. Turn on the AED and follow the steps according to the voice prompts from it. The AED device will analyze the rhythm of the heart and give a shock.

CPR is a Practical Skill, not Just Medical Knowledge

Another reason for reluctance to administer CPR is the notion that it should be administered only by doctors, nurses, and other professionals. However, even basic CPR can be taught to regular citizens using special courses. It takes only a couple of hours of practice for someone to gain enough confidence to use CPR in emergencies.

CPR training should be more accessible in schools, offices, and residential communities, as it would help people know what to do in those critical first few minutes.

Cardiac arrest will not wait for doctors to show up. When cardiac arrest occurs, the first person on the scene might be either a relative, co-worker, friend, or a total stranger. Knowing CPR will prepare you for these moments of life or death. A simple skill learned today may help save someone’s life tomorrow.

(Dr. Lalit Kapoor, Senior Consultant - Cardiac Surgery and Robotic Surgery – Narayana RN Tagore Hospital, Mukundapur, Kolkata)

Worried about your graying hair? It may reflect a natural cellular response to DNA damage, according to a study by Japanese researchers.

Hair color comes from melanocyte stem cells (McSCs), which live inside hair follicles and produce melanin, the pigment responsible for hair and skin color. These cells are especially sensitive to DNA damage from environmental and internal factors.

While DNA damage is linked to both aging and cancer, researchers at the University of Tokyo found that McSCs can take different paths after being damaged — including one that leads to hair graying and another associated with melanoma, a type of skin cancer.

How Does Gray Hair Act As A Defense?

When McSCs suffer certain types of DNA damage, they can undergo a process called senescence-coupled differentiation, or seno-differentiation. The damaged stem cells permanently differentiate and are eventually lost, leading to hair graying.

This response is driven by the p53–p21 pathway and may help eliminate damaged cells before they can become cancerous.

Also read: Unusually High Cancer-Fighting Immune Cells Could Explain Why Some People Live Beyond 100: Study

What Did The Study Find?

Published in Nature Cell Biology, the study examined how McSCs respond to different types of DNA damage.

Professor Emi Nishimura and Assistant Professor Yasuaki Mohri used long-term in vivo lineage tracing and gene-expression profiling in mice to study the fate of these stem cells.

The researchers found that DNA double-strand breaks triggered seno-differentiation. In this process, damaged McSCs irreversibly differentiate and are lost, resulting in hair graying.

However, the response was different when the cells were exposed to certain carcinogens, including 7,12-dimethylbenz(a)anthracene, or ultraviolet B. In these situations, McSCs could bypass the protective differentiation process, retain their ability to self-renew and expand clonally.

This process was supported by KIT ligand signals from the surrounding tissue and epidermis, which suppressed seno-differentiation and pushed the cells toward a tumor-prone state.

“These findings reveal that the same stem cell population can follow antagonistic fates—exhaustion or expansion—depending on the type of stress and microenvironmental signals,” Nishimura said.

“It reframes hair graying and melanoma not as unrelated events, but as divergent outcomes of stem cell stress responses,” she added.

Does Gray Hair Prevent Cancer?

Read More: Ferritin Face: Can Pale Skin Signal Iron Deficiency?

Not necessarily. The study does not show that people with gray hair have a lower risk of cancer.

Instead, the findings suggest that hair graying can be the result of a protective cellular response in which damaged stem cells are eliminated. When that response is bypassed, damaged McSCs may persist and contribute to melanoma development.

The researchers say the findings offer a framework for understanding how the same stem-cell population can contribute to either tissue aging or cancer depending on the type of damage and signals from the surrounding environment.

Can You Prevent Premature Graying?

Genetics plays a major role in when hair turns gray. There are also some lifestyle changes that can prevent graying, support hair and overall health. These include:

• Managing stress
• Eating a nutrient-rich diet
• Protecting your hair and scalp from excessive UV exposure
• Avoiding excessive heat and harsh chemical treatments
• Avoiding smoking.