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.

Morning walks are a popular part of many older adults’ daily routines. But is walking alone enough to maintain bone strength and prevent osteoporosis as we age?

Walking 30–40 minutes every day is a good habit. However, it may not be enough to maintain bone and muscle strength as we age. A person may walk daily and still struggle to get up from a low chair or maintain balance on an uneven surface. These are important signs of functional strength that deserve as much attention as daily step counts, experts said on World Osteoporosis Day.

Falls are a significant concern among older adults worldwide. A 2022 systematic review and meta-analysis of 104 studies estimated that 26.5% of older adults globally experienced falls. In India, a 2026 analysis of data from the Longitudinal Ageing Study in India found that 11.56% of adults aged 60 and older reported a history of falls. Chronic joint disease was among the factors independently associated with falls.

Why Walking Alone May Not Be Enough

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Dr. Siddhart Yadav, Senior Consultant, Orthopedics and Joint Replacement Surgery, Apollo Hospitals, Navi Mumbai, told HealthandMe that bone density and muscle mass tend to decline with age.

“In women, bone loss can accelerate after menopause, while men too are at risk of age-related bone loss. When weaker bones are combined with reduced muscle strength and poor balance, even a relatively minor fall can result in a fracture, particularly around the hip or wrist,” he said.

“While women are hit hardest, often assuming household chores are adequate exercise, men are equally vulnerable as muscle mass silently declines after 50. In both, excess weight paired with weak muscle leaves weaker bones exposed to fractures during simple falls,” Dr. Thineshchandar Andiappan, Senior Orthopaedic and Joint Replacement Surgeon, Athulya Geriatric Hospital told HealthandMe.

What Exercises Should Adults Over 60 Include?

A casual morning walk alone may not provide enough stimulus to maintain bone density, muscle strength, and balance. Experts recommend combining walking with progressive resistance and strength training. Starting in your 40s can help preserve strength, but it is never too late to begin an appropriate exercise routine.

Along with regular walking, older adults should include simple strength and balance exercises in their routine.

Dr. Siddhart suggested chair sit-to-stands, supported squats, heel raises, and resistance-band exercises to help maintain the strength needed for everyday activities. Light dumbbell exercises for the upper body can also help strengthen the arms, shoulders and other upper-body muscles.

Exercises should be introduced gradually and tailored to individual health and mobility, particularly for people with osteoporosis or a history of fractures.

A 30-40-minute walk is beneficial, but it does not have to be completed in one stretch. If the muscles begin to feel tired, taking a short break of two to three minutes before resuming the walk is reasonable.

Diet and Vitamin D Also Matter

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Along with exercise, adequate nutrition supports bone and muscle health. Calcium-rich foods such as milk, curd, paneer, ragi and sesame, together with adequate protein, can help meet nutritional needs. Vitamin D levels should be assessed when clinically indicated.

“Falls in elderly persons happen more often due to instability, muscle weakness, and other reasons. It is very important to address all the issues in addition to the management of osteoporosis for preventing such fractures. The comprehensive treatment will include a good diet, adequate sunlight exposure, in addition to exercises, which must involve weight training and stability-building training,” Dr. V Singaravadivelu, Senior Consultant and Academic Lead, Orthopaedic Surgery, Kauvery Hospital told HealthandMe.

A sugar naturally found in red meat may help explain why beef and lamb have long been linked to type 2 diabetes, according to a large new study presented at the European Association for the Study of Diabetes’ Annual Meeting in Milan.

Researchers tracked nearly 90,000 adults with no history of diabetes or cancer through NutriNet-Sante, a long-running French health study, according to a release from the European Association for the Study of Diabetes (EASD). Over a median follow-up of 7.2 years, 966 participants developed type 2 diabetes.

The focus was a sugar called N-glycolylneuraminic acid, or Neu5Gc, found mainly in beef and lamb. People with the highest intake of meat-derived Neu5Gc had a 63% higher risk of developing type 2 diabetes than those with the lowest intake, the EASD reported. The risk rose steadily with intake: the second-highest group already carried a 41% higher risk.

“This is a relative risk: people in the top fifth of meat-derived Neu5Gc intake had a 63% higher risk than those in the bottom fifth, after accounting for many other factors,” said lead author Dr. Leopold Fezeu of Universite Sorbonne Paris Nord told Medical News Today. “It does not mean that 63% of high consumers will develop diabetes.”

Also Read: World Osteoporosis Day: Why Women Face A Higher Risk of Osteoporosis As They Age

Why Scientists Suspect Inflammation

Most mammals produce Neu5Gc naturally, but humans lost that ability after an ancient genetic mutation, according to the EASD. The sugar can still enter the body through food and get absorbed into human tissue. Because the body doesn’t recognise Neu5Gc as its own, the immune system may treat it as foreign, producing antibodies against it in a prolonged immune response called xenosialitis, previously linked to cardiovascular disease and cancer.

“Our findings support chronic inflammation as a specific mechanism linking red meat consumption with T2D, partly beyond the amount of red meat a person eats and partly independent of body fat,” Fezeu said.

What Are The Key Findings?

Not just weight: Notably, obesity accounted for only about 13% of the link between Neu5Gc intake and diabetes risk, the EASD reported, suggesting the sugar’s effects may extend beyond weight gain alone.

Dairy showed no link: Despite also containing Neu5Gc, dairy products showed no association with diabetes risk, likely because cow’s milk contains far smaller amounts than red meat.

An important caveat

When researchers additionally adjusted for total red meat intake, the Neu5Gc-diabetes link weakened and was no longer statistically significant, though it pointed the same direction.

“There may be differences between sources, or other components of red meat may contribute,” Fezeu said, meaning the study can’t fully separate Neu5Gc’s effect from red meat generally.

What comes next

Since the study is observational, it cannot prove Neu5Gc causes diabetes. Fezeu’s team plans to measure antibodies against Neu5Gc directly and study how it interacts with iron in red meat.

“Future research should explore whether reducing exposure to meat-derived Neu5Gc, for example by favoring poultry or plant-based proteins over beef and lamb... could help prevent T2D,” Fezeu said.

As we brace ourselves for another bout of winter, we can’t help but feel wary about the changes the dip in temperature brings on our mood and mental well-being. You are not imagining winter depression when you start to feel sudden loss of joy.

Seasonal depression is more than feeling gloomy. You may no longer enjoy the activities you once relished, like listening to music, exercising or meeting friends. This isn’t just another effect of winter. Experts have designated a term for it: anhedonia.

Anhedonia refers to the loss of pleasure or interest in something you once enjoyed. It is one of the symptoms of depression, including seasonal affective disorder (SAD). Unlike sadness, anhedonia can render someone feeling disconnected with or indifferent towards things they once enjoyed.

A person experiencing anhedonia may still participate in activities they enjoy but will no longer reap emotional rewards from it.

“Anhedonia is not the kind of sadness where you’re feeling down but still have moments of enjoyment,” Dr Deeksha Kalra, Associate Consultant, Psychiatry, Artemis Hospital, Gurugram, explained to HealthandMe.

Dr Samant Darshi, Consultant Psychiatrist and Neuromodulation Expert at Yatharth Hospitals, told us, “While sadness entails the state of feeling unhappy about something, anhedonia pertains to the lack of enjoyment.”

Dr Kalra said, during SAD, anhedonia may be experienced during the affected season like winter.

“This can happen at the same time as low mood, but it can also be one of the clearest symptoms. In SAD, these changes are usually present during the affected season and resolve with the resolution of the depressive episode. So anhedonia is about muted pleasure, not just feeling sad,” Dr Kalra explains.

Effects Of Winter On Pleasure And Motivation

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Changes that come with SAD, a type of depressive phase, usually pertains to specific seasons, like mostly winter. Due to less duration of daylight, the body’s internal clock, known as circadian rhythm, may get affected. Along with circadian rhythm, poor diet, irregular sleep pattern and limited physical activity can also contribute to SAD.

This could cause one to feel difficult to initiative activities they enjoy as they no longer feel motivated, affecting the brain reward system.

“Seasonal affective disorder (SAD) causes disturbance of mood, sleep, energy, and motivation. Activities which were pleasurable before become less rewarding because of this. The changes in daylight hours may affect the body clock or the physiological processes related to mood control. The decrease in energy and motivation makes doing the activity even harder and less pleasurable,” said Dr Darshi.

Dr Kalra explains that there are a lot of phases to experiencing ‘enjoyment’. It involves identifying something rewarding, anticipating it, experiencing pleasure and learning from the experience. Depression can affect all these phases, making previously enjoyable activities feel less rewarding.

“Brain networks including the striatum and nucleus accumbens, contribute to the valuation of rewarding experiences and the motivation of behavior. When their responses are dulled and something that was once naturally rewarding may not have the same emotional resonance,” she says.

Dopamine’s Role In SAD

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Dopamine is a neurotransmitter in the brain responsible for motivation, rewards, learning, and directing behaviour as per goals. When we talk about SAD and anhedonia, dopamine comes into the picture as it is related to motivation and rewards.

Dr Kalra explained, “Dopamine is involved in motivation, reward anticipation, learning and determining the value of pursuing something. That’s why dopamine has been looked at when researchers have investigated anhedonia and low motivation.”

But doctors say that anhedonia is not characterised by shortage of dopamine. According to research, SAD has been reported to affect dopamine signalling, including lower dopamine transporter availability in the striatum during symptomatic depression.

Dr Darshi also emphasises that dopamine is only a part of the process.

He said, “Studies concerning depression and anhedonia indicate that changes in the activity of dopamine result in the decrease in motivation and reward sensitivity. However, anhedonia encompasses many brain processes.”

SAD And Anticipatory Pleasure

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Anhedonia makes one indifferent by directly affecting the anticipatory pleasure mechanism. Anticipatory pleasure is the excitement one feels before an event. Consummatory pleasure is the enjoyment experienced while the event is in progress.

“Anhedonia can affect the anticipatory pleasure you feel when you look forward to something and the consummatory pleasure you experience when it actually happens. Someone might know that a favorite meal, holiday or meeting with friends should be enjoyable but feel little excitement beforehand. The pleasure might also feel weaker than expected when the event happens,” Dr Kalra explains.

Not Everyone May Experience Same SAD Symptoms

Everyone with SAD experiences anhedonia in different ways. While some may lose interest and pleasure, others may withdraw socially, sleep excessively, eat more, feeling more tired among other symptoms.

“SAD doesn’t affect everybody in exactly the same way any more than depression is a single biological process. Different people can experience different combinations of changes in mood regulation, circadian rhythms, sleep, appetite and energy and reward processing,” says Dr Kalra.

She also said that multiple symptoms may interact. For example, poor sleep could result into daytime sluggishness, making energetic activities less tempting.

Dr Darshi explained, “Individuals with SAD have different presentations since biology, genetics, circadian rhythm, and psychology are unique for each person. Some individuals have disturbances in reward and motivation, whereas others have sleep disturbances or carbohydrate cravings, or even fatigue. Symptoms might be overlapping and are a reflection of various underlying mechanisms.”