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.

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?"

GLP-1 receptor agonists have established themselves as one of the most sought-after treatment methods to manage type 2 diabetes. Conversations around these drugs often focus on their ability to improve blood sugar control, promote weight loss and support metabolic health. However, what happens after a patient takes the first dose deserves equal attention.

These medications, which include semaglutide, liraglutide and dulaglutide, mimic a naturally occurring hormone called GLP-1. They stimulate insulin release when blood glucose is high, suppress glucagon, slow stomach emptying and promote a feeling of satiety to reduce cravings.

While there are plenty of benefits, GLP-1 medications are not suitable for everyone. Existing digestive conditions, other diabetes medications, kidney function and even retina health can influence how safely a patient responds to treatment.

On World Diabetes Day, doctors explain why starting GLP-1 therapy requires more than checking blood sugar levels, and what patients should know about its complications. They also discuss lesser-known side effects a patient may face after the first dose.

Who Can And Cannot Take GLP-1 Drugs To Manage Diabetes?

Also read: Why Does Type 2 Diabetes Increase The Risk Of Alzheimer’s Disease? Neurologist Explains

Before initiating GLP-1 treatment, doctors need to understand a patient's overall health, diabetes as well as medication history. This includes checking HbA1c levels, blood glucose patterns, kidney function and any history of pancreatitis, gallbladder disease or gastrointestinal problems.

Dr Bibhu Anand, Internal Medicine Specialist at Sir Ganga Ram Hospital, told HealthandMe that treatment decisions must be made according to the patient’s history.

He said, "We see the patient's HbA1c, blood glucose profile, kidney function, medicine history, and medicine prior to the first dose in detail. We specifically identify patients already receiving insulin or sulfonylureas, as these doses may require modification to reduce the risk of hypoglycemia.”

Patients with a personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2 are generally advised against using these medications.

Dr Anand said that those with a history of pancreatitis, severe gastrointestinal disease or gallbladder problems may also need assessment. The objective is generally to establish whether the benefits outweigh the risks.

GLP-1 GI Side Effect Or Diabetic Gastroparesis?

Also read: Stopping Mounjaro & Zepbound May Trigger Hallucinations, Mania & Other Psychiatric Symptoms

Nausea, bloating, vomiting, constipation and diarrhoea are among the commonly reported gastrointestinal effects of GLP-1 medications. These symptoms are expected in the initial weeks of treatment or after an increase in dose. However, constant digestive discomfort in someone with diabetes should not be neglected.

Dr Richa Chaturvedi, Senior Consultant and Endocrinologist at Indraprastha Apollo Hospitals, Delhi, told HealthandMe that diabetic gastroparesis can cause symptoms that closely resemble gastrointestinal side effects due to GLP-1 drugs.

Gastroparesis develops when nerve damage related to diabetes affects food movement through the stomach. Patients may experience frequent nausea, early fullness, vomiting food consumed several hours earlier and unpredictable blood glucose levels. Unlike discomfort due to medicines, these symptoms may already exist before treatment begins.

"The key difference lies in the onset and pattern of symptoms. GLP-1 medications slow gastric emptying, meaning food remains in the stomach longer. This can cause nausea, bloating, belching and early fullness, particularly when treatment begins or the dose increases. These symptoms may settle as the body adapts."

Dr Chaturvedi emphasises that gastrointestinal symptoms should be assessed before starting treatment, especially in patients with chronic diabetes.

A gastric emptying study can be done if symptoms suggest gastroparesis. GLP-1 medications are generally not recommended for patients with severe gastroparesis, as they can further delay stomach emptying and affect nutritional intake.

Pancreatitis, Gallstones And Dehydration Risk

Also read: Semaglutide May Lower Fetal Oxygen Levels During Pregnancy, Sheep Study Finds

Although mild digestive discomfort may improve as the body adjusts to treatment, certain symptoms require immediate attention.

Severe pain in the upper abdomen or pain radiating towards the back, can indicate pancreatitis. Repeated vomiting, an inability to retain fluids, significant dizziness, reduced urination and upper-right abdominal pain accompanied by fever are other warning signs.

Dr Chaturvedi explains that pancreatitis has been reported during GLP-1 treatment, although it is uncommon and a causal relationship has not been established.

She said, “Gallbladder complications, including gallstones and inflammation, have a more established association with GLP-1 treatment. Rapid weight loss is an important contributing factor, as it can increase the likelihood of gallstone formation. Changes in gallbladder emptying may also play a role.”

Another concern is kidney injury due to dehydration. Persistent nausea and vomiting can reduce fluid intake, potentially affecting kidney function, particularly in patients who already have kidney disease.

Patients should therefore not dismiss severe abdominal pain or prolonged vomiting as routine side effect of the drug.

Diabetics Need Eye Testing Before Starting GLP-1 Therapy

Also read: Stopping Ozempic or Wegovy May Double Your Risk Of Heart Attack, Death

Digestive complications are not the only concern after starting GLP-1 medications. For patients with diabetes, retina health also warrants attention.

Dr Parul Maheshwari Sharma, Principal Director and Head of Ophthalmology at FMRI Gurgaon, told HealthandMe that a rapid improvement in blood glucose levels can sometimes cause an initial, temporary worsening of diabetic retinopathy. This phenomenon is known as early worsening of diabetic retinopathy.

Dr Sharma explained, “When blood sugar levels fall substantially over a short period, changes in retinal blood flow and vascular regulation may affect blood vessels that are already damaged. The concern is particularly relevant for patients with poorly controlled diabetes, high baseline HbA1c levels or pre-existing retinopathy.”

Patients with long-standing or poorly controlled diabetes, existing retinopathy or high HbA1c levels should ideally undergo a dilated retinal examination before initiating treatment, especially when substantial glucose reduction is anticipated.

Rare Vision Complication Patients Should Know About

Another emerging area of concern is non-arteritic anterior ischaemic optic neuropathy (NAION), a rare condition caused by reduced blood supply to the optic nerve that can result in sudden, permanent vision loss.

Some observational studies have reported an association between GLP-1 medications, particularly semaglutide, and NAION. However, a direct cause-and-effect relationship has not been established, and the evidence is still evolving.

Dr Sharma explains that this condition is different from diabetic retinopathy. While retinopathy affects the blood vessels in the retina, NAION involves damage to the optic nerve due to reduced blood supply.

Patients should be aware of warning signs such as sudden, painless blurring or loss of vision, particularly in one eye. Patients experiencing sudden visual changes should not wait for symptoms to resolve on their own.

She said, “Other symptoms include dark patches or blind spots in the visual field, distorted colour perception and difficulty seeing centrally. Sudden flashes, floaters or a curtain-like shadow across the vision also warrant urgent ophthalmological assessment. These symptoms could indicate conditions such as NAION, retinal complications or other sight-threatening emergencies.”