The COVID-19 pandemic may be over, but our immune systems are still feeling the impact. After years of battling constant viral threats, from COVID-19 to seasonal flu and other infections, our body’s defense system is exhausted. Many people continue to experience lingering inflammation, frequent illnesses, and slower recovery times. This extended state of immune stress has compromised us further to chronic illness, including autoimmune diseases and even neurodegenerative diseases such as Parkinson's. So why is our immune system still in trouble? And how do we give it its power back? Understanding immune exhaustion is the beginning of rebuilding our body's natural immunity.

A weakened immune system makes people more susceptible to disease, mental illnesses, and even sleep disorders. Now, new research indicates that immune system depletion may play an important role in the onset of Parkinson's disease, a degenerative neurologic disorder that compromises movement and cognition.

Role of Inflammation in Parkinson's Disease

Dysfunctional immune response is a leading cause of long-standing inflammation within the body, that has been found to contribute towards a multitude of conditions, including cardiovascular conditions, diabetes, depression, and neurodegenerative diseases such as Alzheimer's.

As people age, their immune system naturally becomes less effective. This deterioration, referred to as immune exhaustion, may be a key contributor to the onset and progression of Parkinson’s disease. Rebecca Wallings, a Parkinson’s Foundation Launch Award grant recipient and senior postdoctoral fellow at the University of Florida, believes that an accumulation of exhausted immune cells could be driving neurodegeneration in Parkinson’s patients.

How a Tired Immune System Might Affect Parkinson's?

Parkinson's disease is most commonly linked with the degeneration and loss of dopaminergic neurons—motor nerve cells that produce dopamine, an essential neurotransmitter for movement. While researchers have long suspected inflammation is involved in this neurodegeneration, the mechanisms are not yet well understood.

Wallings' study is on immune cell exhaustion, a process by which aging immune cells fail to control immune responses effectively. Her research indicates that instead of dampening inflammation in Parkinson's patients, attempts should be made to rejuvenate the immune system to regain its functionality.

Energy Deficiency in Immune Cells

One of the major findings of Wallings' work is the function of mitochondrial impairment in immune cell exhaustion. Mitochondria are commonly called the powerhouses of cells, as they are vital for generating energy. As mitochondria age and become inefficient, immune cells fail to function well, potentially accelerating neurodegeneration in Parkinson's disease.

Wallings has found that mutations in the LRRK2 gene, a recognized genetic risk factor for Parkinson's disease, are linked with defective mitochondrial function and immune cell exhaustion. Her current work includes testing various therapeutic approaches to restore mitochondrial function in immune cells with the potential to enhance the immune system and potentially prevent or treat Parkinson's disease.

Will Rejuvenating the Immune System Help in Treatment?

For decades, the standard practice in treating Parkinson's has been to suppress brain inflammation. Yet Wallings' work indicates that instead of slowing down immune responses, restoring the immune system could be a more successful strategy. By addressing mitochondrial impairment and immune resilience, researchers can potentially reverse or slow down Parkinson's disease.

Wallings is now looking into how to rejuvenate immune cells by fixing mitochondria. She studies immune cells from patients with Parkinson's as well as from healthy subjects and performs experiments on animal models to determine if rejuvenation of the immune system could result in improved disease outcomes.

Lifestyle Factors That May Affect Parkinson's Risk

While there is no cure for Parkinson's disease, some lifestyle adjustments may decrease the chances of developing the illness. Since neurodegenerative diseases are associated with chronic inflammation and immune dysfunction, developing habits that enhance immune function might prove helpful.

Diet: There is evidence to suggest that eating in accordance with the Mediterranean or MIND diets, both high in antioxidants, healthy fats, and anti-inflammatory foods, can encourage brain wellness and reduce Parkinson's risk.

Avoiding Dangerous Substances: Restricting alcohol and nicotine use can maintain a robust immune system and suppress inflammation.

Reducing Stress: Chronic stress weakens immune function, so methods such as meditation, exercise, and sufficient sleep can lead to improved overall well-being.

Every year during winter after Diwali, much of India finds itself wrapped in a grey blanket of smoke and smog. The festival of lights, which should bring joy surrounded by family and friends, is now characterised by hazy mornings, stinging eyes, and a lingering cough that many have come to accept as ‘normal’ for the season. Firecrackers, vehicle fumes, construction dust, and crop burning together also push the air quality indices up in many cities like Delhi NCR and Patna to alarmingly unsafe levels.

In clinics we see sick people walk in every November with the same symptoms as the previous years—children wheezing, grandparents struggling to breathe, and adults who have smoked for years ignoring a cough that deserves attention. As a pulmonologist, I want to explain in simple terms how smoke, smog and tobacco affect our lungs and what each of us, from the youngest child to the oldest grandparent, can do to protect them.

Why the Lungs Are So Vulnerable

With every breath our lungs are in contact with the outside world, inhaling the air around. Millions of tiny air sacs pass oxygen into the blood, while microscopic hairs lining the airways sweep out dust and germs.

This natural defence works remarkably well, but years of exposure to smoke or polluted air can wear it down. Once the airways are inflamed and the cleaning system weakens, the lungs become more prone to infection, chronic respiratory disease, and in some people, even cancer.

Also read: Is It Just A Persistent Cough Or Is Your Body Telling You Something Else?

Tobacco: The Leading Preventable Cause

Tobacco smoke contains many carcinogens, which are chemicals that can even damage DNA (deoxyribonucleic acid) in our cells. Recent research shows that cigarette smoke reduces the ability of the cells to repair this damage, leaving them unstable and likely to turn cancerous. Another study found that smoking leaves a distinct signature in our DNA and disrupts proteins that normally stop tumours from growing.

The risk is substantial, and reports indicate that the risk of lung cancer in smokers rises by 24 to 36 times more than non-smokers. Smoking also harms those around the smoker, because children and elderly family members who breathe second-hand smoke at home carry a very real risk even though they never made that choice to inhale smoke.

Smoking continues to affect a patient’s outcome even after lung cancer has been diagnosed. A large international analysis of nearly 49,000 patients across 25 countries found that a patient’s smoking status can influence survival as strongly as the traditional factors doctors use to stage the disease, such as the size of the tumour and whether it has spread to nearby lymph nodes.

In fact, among patients with early-stage disease, smoking history had a greater impact on prognosis than whether the cancer had spread to nearby lymph nodes. A parallel study found that quitting smoking within six months of diagnosis improved median survival by about four years across cancer types. In other words, stopping smoking remains one of the most powerful steps a patient can take at any stage of the disease.

Air Pollution: A Growing Concern

The threat to our lungs does not come from smoking alone. Many cities see air quality worsen sharply in the weeks around Diwali and early winter, as construction dust, vehicle emissions, crop burning, and firecrackers add fine particles to the air. These particles are small enough to travel deep into the lungs and enter the bloodstream.

Polluted air worsens asthma, bronchitis and COPD, and long-term exposure is also linked to lung cancer, including in people who have never smoked. Some city administrations have started responding to this grave health issue with work-from-home advisories and curbs on construction activity during certain hours. But there is more to be done.

Children and Older Adults Need Extra Care

Children and older adults are the two groups I worry about most. Children breathe faster relative to their body size as their lungs are still developing.

So they absorb more pollutants than adults do in the same environment. Older adults often have reduced lung reserve if they have other conditions such as diabetes, heart disease, or old tuberculosis scarring. This means, even one bad air day can affect them more severely.

Also read: Sperm Under Heat: Traffic, AQI, and the Dual Thermal Trap

Symptoms That Need Attention

Lung cancer often causes no symptoms in its early stages, which makes awareness all the more important.

Please consult a doctor if you or a family member has a cough lasting more than three weeks, blood in the sputum, persistent chest pain or breathlessness, wheezing or hoarseness that does not settle, or unexplained weight loss and fatigue. Many of these have simple and treatable causes, but only an examination can tell. An early visit can save a life.

Practical Steps and Advice

For families with children, I recommend keeping them indoors on severely polluted days, allowing outdoor play only when the air is clear. Avoid smoking around them or in closed rooms. A cracker-free Diwali is one of the kindest gifts we can give young lungs, choosing instead to celebrate with diyas and rangoli which are just as beautiful.

For older adults, it can help to check the air quality before a morning walk, opting to exercise indoors on bad days, and wearing a well-fitted N95 mask in heavy smog. They should also carry with them inhalers and medicines as prescribed by their doctor. Ask about flu and pneumonia vaccination and take them if advised. The most important rule is to avoid tobacco in all forms, including beedis, hookah and chewing tobacco, practice daily slow breathing exercises with gentle physical activity, and keep indoor air free of dust and smoke.

Quitting Is Worthwhile

Many long-term smokers feel it may be late to quit. On the contrary, quitting the habit reduces the risk of lung cancer, even after many years of smoking. Nicotine replacement, medication and counselling all improve the chance of success when a decision to quit is made, and the support of family members makes a great difference to the outcome. For people at high risk, such as long-term heavy smokers over the age of 50, annual screening with a low-dose CT scan may be advised as it can detect cancer at a stage when treatment is most effective. Do discuss with a pulmonologist on whether it is the right approach for you.

We may not be able to control the air outside on our own, but we can control what we inhale into our lungs and how we respond to bad air on high-pollution days. Small, consistent habits protect the lungs for a lifetime. If you have persistent symptoms or concerns regarding your respiratory health, do not wait beyond a couple of weeks; an early consultation can make all the difference between cancer diagnosis and good health.

By Dr. Prahalad Elamarthi, Consultant, Medical Oncology, Narayana Health City, Bengaluru

Once recognised primarily as a cause of respiratory problems, air pollution is increasingly being linked to cardiovascular and metabolic health concerns, among others. Emerging evidence suggests that long-term exposure to fine particulate matter (PM2.5) may also increase the risk of Type 2 diabetes.

With India facing high pollution levels and a growing diabetes burden, experts on the occasion of World Diabetes Day 2026 stressed that cleaner air must become part of the wider conversation on diabetes prevention.

Air Pollution And Diabetes: What's The Link?

"Fine particulate air pollution (PM2.5) may contribute to insulin resistance by triggering inflammation and oxidative stress in the body. These processes can affect the liver, muscles and fat tissue, potentially interfering with insulin action," Dr Anoop Misra, Executive Chairman and Director, Diabetes and Endocrinology, Fortis C-DOC Hospital, told HealthandMe.

A recent review of 13 systematic reviews, covering over 200 million cumulative participant observations, led by Dr Misra's team, found that long-term PM2.5 exposure was associated with a 10–16% higher relative risk of developing Type 2 diabetes for every 10 μg/m³ increase in exposure.

This is particularly concerning for India, where pollution levels and diabetes prevalence are both high.

Since nearly everyone is exposed to outdoor air pollution, even relatively small increases in individual risk could translate into millions of additional diabetes cases.

Also read: Why Some Diabetes Patients May Not Be Suitable For GLP-1 Treatment, Experts Explain

Dr Misra stated that pollution may also add to the effects of genetic susceptibility, abdominal obesity, unhealthy diets and physical inactivity. However, its role in the rising incidence of diabetes among younger people remains uncertain. Evidence that pollution directly worsens glucose control in people who already have diabetes is also limited.

Dr V Mohan, Chairman of Dr. Mohan's Diabetes Specialities Centre, told HealthandMe that PM2.5 pollutants can trigger inflammation and oxidative stress, potentially affecting insulin function. He added that lifestyle changes, unhealthy diets, physical inactivity, stress, obesity and genetic factors also play important roles in the rising incidence of diabetes among younger Indians.

Can Cleaner Air Help Prevent Diabetes?

Dr Mohan said diabetes prevention should go beyond healthy eating, exercise and weight management to consider environmental factors.

People can check daily AQI levels, avoid exercising near busy roads, use well-fitted N95 masks when exposure is unavoidable and consider HEPA air purifiers indoors.

Dr Misra also emphasised that reducing exposure through cleaner air, better urban planning and effective pollution control should be part of India's diabetes-prevention strategy.

The experts highlighted the need for collective action to identify and address the major contributors to air pollution. Individuals can also avoid strenuous outdoor activity on highly polluted days, while indoor HEPA filtration may help reduce exposure.

Read More: HbA1c Test May Not Be Accurate For Everyone: Who Should Not Rely On It?

Does Pollution Mean Earlier Diabetes Screening?

People living in polluted cities should be more conscious of their metabolic health. However, there is currently insufficient evidence to recommend additional screening solely based on air pollution exposure, Dr Mohan said.

India's screening recommendations advise testing adults from the age of 30, with earlier screening for those with additional risk factors such as obesity, family history and high blood pressure.

Current guidelines do not specifically consider air pollution as an independent screening criterion. Dr Misra also noted that pollution exposure alone does not justify a separate, earlier diabetes screening schedule.

Early screening, healthy lifestyles and a cleaner environment can together help reduce India's diabetes burden. Clean air must be recognised as an important component of a healthy metabolic environment.

With public health experts raising concerns about ultra-processed foods (UPFs), food brands are increasingly using health-focused claims such as ‘natural’, ‘multigrain’ and ‘immune-boosting’ to appeal to health-conscious consumers. But do these labels actually mean the products are healthy, particularly for children?

Research has linked diets high in ultra-processed foods, processed meat and sugar-sweetened beverages to several health concerns. This is particularly concerning amid rising childhood obesity, which can increase the risk of conditions such as diabetes and hypertension. Children's food choices and eating habits can also influence their health later in life.

So, how can parents distinguish genuine nutritional value from clever food marketing? To understand how we may be mistaking food marketing for healthy eating, HealthandMe spoke to experts.

Are ‘Natural’ And ‘Multigrain’ Packaged Foods Really Healthy?

Also read: High Sugar, Salt Or Fat? India May Mandate Red Hexagon Labels On Food Packs

Food marketing requires critical evaluation before a product is considered genuinely healthy, experts said. Terms such as ‘natural’, ‘superfood’, ‘immune-boosting’ and ‘low-fat’ are often marketing claims and do not necessarily reflect a product's overall nutritional value.

Beyond individual food products, experts emphasise the importance of overall dietary patterns in determining long-term health. From a cancer perspective, large cohort studies and the World Cancer Research Fund have linked diets high in processed meat, sugar-sweetened beverages and ultra-processed foods to an increased risk of cancer. Diets rich in whole grains, vegetables, fruits, legumes and fibre, on the other hand, are associated with a lower risk.

No single food prevents cancer; the overall dietary pattern matters.

"The main myth about packaged foods is that generic terms like 'organic', 'natural' and 'multigrain' automatically label the product as healthy. These look at the surface and tell us nothing of the overall food picture," Dr Narendra BS, Lead Consultant, Endocrinology, Aster Whitefield Hospital, told HealthandMe.

He explained that parents should look beyond these claims and examine what has been added to a product and whether it is replacing healthier foods in a child's diet. For example, replacing a whole fruit with a packaged fruit drink can decrease fibre intake and increase free sugars.

How Can Ultra-Processed Foods Affect Children's Health?

Read More: Every Extra 100g Ultra-Processed Food Linked To 14% Higher Heart Risk, 11% Higher BP Risk

Consuming large quantities of sugar-laden drinks and energy-dense foods can increase calorie intake and contribute to weight gain. In children, this can also increase the risk of insulin resistance and other metabolic abnormalities from an early age, Dr Narendra said.

Dr Smitha Saldanha, Senior Consultant, Medical Oncology, HCG Cancer Hospital, KR Unit, Bangalore, said excess body fat is a risk factor for cancer. Sugar-sweetened beverages and other foods associated with weight gain can contribute to this risk over a person's lifetime.

"We know that excess body fat is a risk factor for cancer, and sugar-sweetened beverages and other foods tied to weight gain are one of them in terms of lifetime risk. That is, most people who eat a bad diet at the beginning of their life with high amounts of ultra-processed foods and refined carbs tend to do the same later in life," she told HealthandMe.

READ: Exclusive: From IPL To Olympics — How Sport Became A Marketing Tool For Junk Food And Sugary Drinks

She added that the focus should be on maintaining a balanced diet and avoiding excessive consumption of ultra-processed foods and refined carbohydrates.

"Sugar in and of itself, any ultra-processed food, for that matter, should not be the focus of cancer. It's about eating in a balanced manner, balanced portions, and avoiding excess consumption of ultra-processed, refined carbohydrate-heavy foods every day or multiple times a week."

How Can Parents Identify Healthier Packaged Foods?

Rather than relying on claims printed on the front of a package, parents should examine the nutrition information and ingredients, the experts advised.

Dr Narendra urged parents to compare nutrition labels, particularly serving sizes, and prioritise whole or minimally processed foods.

"I would challenge all parents to start comparing the nutrition label, in particular the serving sizes, and never underestimate the power of whole or minimally processed foods. Not to scare them against all packaged foods, but to make sure that convenience doesn't overtake nutrition."

Dr Smitha also advised consumers to turn the package over and check its nutritional information.

"Flip it over, read the label, scan for sodium and added sugars, and ask: is this label talking about the product or just marketing it? And you be the judge: is this really a healthy choice?"