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.

White sugar is widely known for its harmful effects on health. As a result, many people—especially those with Type 2 diabetes—turn to low- and no-calorie sweeteners such as aspartame, saccharin, and erythritol, believing they are a healthier alternative.

However, a new study published in Neurology, the medical journal of the American Academy of Neurology, has again suggested that higher consumption of certain artificial sweeteners may be associated with faster declines in memory and thinking skills over time.

The researchers stressed that the findings do not prove these sweeteners cause cognitive decline. Instead, they show an association, meaning other factors could also contribute to the observed pattern.

"Low- and no-calorie sweeteners are often seen as a healthy alternative to sugar. However, our findings suggest certain sweeteners may have negative effects on brain health over time," said study author Claudia Kimie Suemoto from the University of São Paulo, Brazil.

What Did the Study Find?

The study followed 12,772 adults in Brazil, with an average age of 52 years, for approximately eight years. Researchers examined the intake of seven commonly used low- and no-calorie sweeteners:

• Aspartame
• Saccharin
• Acesulfame K
• Erythritol
• Xylitol
• Sorbitol
• Tagatose

These sweeteners are commonly found in ultra-processed foods and beverages, including flavored water, soft drinks, energy drinks, yoghurt, desserts, and products marketed as low-calorie. Many are also sold separately for use in coffee, tea, cooking, and baking.

The researchers found that people with the highest total intake of sweeteners experienced a 62% faster decline in overall thinking and memory abilities than those with the lowest intake. This difference was estimated to be comparable to about 1.6 additional years of brain ageing.

Participants in the middle consumption group also showed a 35% faster decline, equivalent to approximately 1.3 additional years of ageing.

The association was especially strong among people with diabetes, who are more likely to use artificial sweeteners as sugar substitutes.

Stronger Link in Adults Under 60

Age also appeared to influence the findings. Among participants younger than 60, those who consumed the highest amounts of sweeteners experienced faster declines in verbal fluency and overall cognitive performance than those with the lowest intake.

Researchers did not observe the same association among participants aged 60 years and older. The study found that aspartame, saccharin, acesulfame K, erythritol, sorbitol, and xylitol were associated with faster declines in overall cognition, particularly memory. Tagatose was the only sweetener not linked to cognitive decline.

"While we found links to cognitive decline for middle-aged people both with and without diabetes, people with diabetes are more likely to use artificial sweeteners as sugar substitutes," Suemoto said. "More research is needed to confirm our findings and to investigate if other refined sugar alternatives, such as applesauce, honey, maple syrup or coconut sugar, may be effective alternatives."

Are There Any Limitations?

The researchers also acknowledged several limitations in study :

• It did not evaluate every artificial sweetener currently used in foods and beverages, so the findings cannot be applied to all sugar substitutes.
• Dietary intake was self-reported, meaning participants may have inaccurately remembered or estimated what they consumed.
• The study was observational, meaning it identified an association but cannot establish that artificial sweeteners directly caused cognitive decline.

Brain disorders are becoming one of India's fastest-growing public health challenges, said health experts ahead of Brain Day on July 22.

The experts highlighted that an ageing population, rising lifestyle diseases and limited access to specialist care are contributing to an increasing burden of conditions such as stroke, epilepsy, Parkinson's disease, dementia and multiple sclerosis.

Access Gap Delays Diagnosis, Treatment

Dr. Madhukar Bhardwaj, Director & Head of Department, Neurology, Aakash Healthcare, said neurological disorders have become one of India's most urgent healthcare concerns.

"Neurological disorders are no longer a concern of a small section of the population—they are one of the most pressing emerging healthcare challenges of our time. In a country as vast and diverse as India, with a rapidly ageing population, this is a matter of urgency. What makes the situation even more worrying is the lack of equitable access to care," he said.

According to the World Health Organization's Global Status Report on Neurological Disorders (2025), India faces a severe shortage of neurologists, with the neurologist-to-patient ratio nearly 80 times worse than in high-income countries, leaving specialist care concentrated in major cities.

Stroke Increasingly Affects Younger Adults

Experts also highlighted a worrying shift in disease patterns, with strokes increasingly affecting younger people. Dr. Bhardwaj said strokes, once considered a disease of older adults, are now being seen more frequently among people in their 30s and 40s, underscoring the need for greater awareness and prevention.

Lifestyle Diseases Driving Brain Disorders

Doctors identified uncontrolled hypertension, diabetes, obesity, smoking, chronic stress, physical inactivity and poor sleep as major contributors to the rising burden of neurological diseases.

Dr. Rajas Deshpande, Consultant and Head of Neurology, Jupiter Hospital, Pune, said many neurological conditions share common lifestyle-related risk factors.

"Controlling hypertension, diabetes, obesity, smoking and physical inactivity can significantly reduce the risk of stroke and vascular dementia. Prevention deserves as much attention as treatment because many neurological disorders share common modifiable risk factors," he said.

Early Diagnosis Can Improve Outcomes

Dr. Bhardwaj stressed that many neurological disorders progress silently, making early diagnosis critical.

"Whether it is stroke, epilepsy, Parkinson's disease or memory disorders, early diagnosis can significantly improve outcomes. Unfortunately, many patients seek specialist care only after the disease has advanced, either because symptoms are ignored or because neurological services are not easily accessible. Greater public awareness and timely referrals are essential," he said.

Brain Health Linked to Women's Reproductive Health

Experts also emphasized that brain health extends beyond cognition. Dr. Hrishikesh Pai, Consultant Gynecologist & IVF Specialist, Lilavati Hospital Mumbai and Fortis Hospitals Delhi & Chandigarh, said the brain plays a central role in regulating women's reproductive health.

"Brain health plays a critical role in women's reproductive health. The hypothalamus and pituitary gland in the brain regulate the hormonal signals that control menstruation, ovulation, and pregnancy," he said.

He added that chronic stress, neurological disorders, pituitary diseases and certain medications can disrupt hormonal balance, leading to irregular menstrual cycles, infertility and pregnancy-related complications.

As wildfire smoke continues to affect communities across North America and Europe, fertility experts are recommending people undergoing vitro fertilization (IVF) to pay attention to an overlooked factor before embryo implant: air quality.

A new study suggests that exposure to unhealthy levels of air pollution, particularly from wildfire smoke, could significantly reduce the chances of a successful pregnancy after IVF.

Researchers, therefore, recommend discussing the timing of embryo transfer with a fertility specialist when air quality deteriorates.

Wildfire Smoke May Interfere With Embryo Implantation

The study, published in the journal Human Fertility, indicates that air pollution may affect reproductive health.

Between June and July 2023, researchers from Northwell Fertility in New York examined 190 fresh and frozen embryo transfers, when smoke from massive Canadian wildfires caused hazardous air quality across the northeastern United States.

They then compared the rate of successful pregnancies based on the Air Quality Index (AQI) on the day of embryo transfer.

Clinical pregnancy rates were approximately 62% on days with good air quality and 65% on days with moderate air quality.

But when the AQI rose above 100, a level considered unhealthy for sensitive groups; the pregnancy rate dropped to just 27%.

Although only 11 embryo transfers took place on days with unhealthy air quality, the researchers say the findings raise concerns about whether temporary exposure to wildfire smoke could affect one of the most critical stages of IVF.

Also read: Miles Apart, But Planning A Family Together: The Fertility Reality Of Long-Distance Marriages In India

How Can Air Pollution Affect Fertility And IVF Success Chances?

IVF embryos are created and stored in strictly controlled laboratories, meaning they are protected from polluted air and other contaminants in the environment.

Instead of damaging the embryo, researchers believe that wildfire smoke can affect the woman's body by increasing inflammation and oxidative stress. This could create a less favourable environment for the embryo to implant in the uterus.

Air pollution contaminant, PM2.5, a fine particulate matter, is one of the main pollutants in wildfire smoke. It is minute enough to enter the lungs, bloodstream, and trigger inflammatory responses throughout the body.

Previous studies have already indicated that PM2.5 exposure could cause pregnancy complications and harm fertility.

Dr. Randi Goldman, Program Director at Northwell Fertility and co-author of the study, said the research suggests patients and physicians should consider environmental conditions when planning embryo transfer.

Also read: Global Female Infertility Could Affect 80 Million Women Aged 35+ by 2036: Lancet Study

"The embryo is safely protected inside the laboratory. The effect we're seeing is more likely related to how air pollution influences the body before and after embryo transfer rather than the embryo itself," Goldman said.

She opines that patients experiencing severe wildfire smoke or hazardous air quality should discuss whether delaying embryo transfer by a few days could improve the chances of success.

"Patients invest enormous emotional, physical and financial resources into IVF. Delaying treatment is difficult, but when air quality reaches unhealthy levels, it may be worth discussing timing with your fertility specialist," Goldman said.

Expert-Recommended Tips To Improve IVF Success

Adopt a Fertility-Boosting Lifestyle: Eat a balanced diet, exercise daily, and enjoy a healthy BMI. Reduce alcohol intake, do not smoke, and avoid recreational drugs.

Take Key Supplements: Folic acid, CoQ10, and vitamin D can improve egg quality and overall fertility.

Stress Management Is Key: Elevated cortisol levels can affect reproductive hormones. Practice mindfulness, yoga, or acupuncture.

Sleep Well: Aim for at least 7–8 hours of restful sleep to support hormonal balance.

Address Underlying Health Conditions: Conditions such as PCOS, thyroid issues, and endometriosis can interfere with fertility outcomes if left unmanaged.

Start Early, If Possible: The earlier IVF is initiated—especially for women over 35—the better the chances.