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.

Climate change is not just raising temperatures and intensifying extreme weather. It may also affect digestive health by disrupting food production, threatening water security and changing the spread of gastrointestinal infections, according to two leading gastroenterology experts from the World Gastroenterology Organization (WGO).

Climate change can contribute to heat-related illnesses and influence the geographic spread of infectious diseases, especially in countries like India.

A February 2025 review in The Lancet Planetary Health outlines how the combined effects of climate change could affect the human gut microbiome, including through food insecurity, malnutrition and exposure to disease-causing pathogens. These challenges could alter the composition of gut microbial communities worldwide.

Research suggests that heat stress may alter gut microbes, digestion and immune function. It may also increase intestinal permeability, potentially allowing toxins and pathogens to enter the bloodstream.

Climate-related drought can disrupt food production and reduce access to nutritious food, potentially affecting the gut microbiome. Environmental changes may also influence food- and waterborne pathogens, increasing infection risks where access to safe water and sanitation is limited.

Speaking to HealthandMe, Professor Geoffrey Metz, professor of medicine at the University of Melbourne, said climate change was becoming an increasing concern for gastrointestinal health.

“Certainly, with global warming, we're seeing a lot more infectious diseases in the gastrointestinal tract,” Metz said.

How Climate Change Can Affect Digestive Health

Also read: 'Humanity Can Still Act': Lancet Warns Of 17 Global Health Threats By 2100

Climate change can affect digestive health through several interconnected pathways, including water availability, food production and infectious diseases.

Metz said the consequences of global warming extend beyond rising temperatures.

“The other thing, of course, with global warming—and this is a major interest of the World Gastroenterology Organisation—is that it's not just making us hot, but it's also creating more drought, which interacts with food production. So there's less food available, impacting our nutrition.”

Drought can disrupt food production and reduce food availability, raising concerns about nutrition. Changes in water availability can also make safe food preparation and hygiene more difficult.

However, the extent to which these environmental changes contribute to specific gastrointestinal diseases requires further investigation.

Safe Water And Food Hygiene Remain Essential

Professor Carolina Olano, professor of gastroenterology in Montevideo, Uruguay, and president of the WGO, highlighted the role of environmental factors in digestive diseases.

“Well, I think it's a combination of many factors. You know that there are some things related to genetics, and we have genetic predispositions to some diseases. But there are also environmental factors related to different diseases, and climate change has an impact too. We are working very hard at the World Gastroenterology Organisation to understand how climate change is affecting different diseases.”

Olano also emphasised the importance of safe drinking water and food hygiene in preventing infections.

“It's also important to have a varied diet and to drink safe, clean water, making sure that the water we drink is safe. Food hygiene is also extremely important.”

She told HealthandMe that handwashing was another simple preventive measure.

“We learned from the COVID pandemic that handwashing before eating is extremely important. These are things we can do every day without spending anything, and they can help prevent many important diseases, especially those related to infections.”

Climate Change Has Wider Health Consequences

Read More: Climate Change Is Affecting Skin Health Worldwide, Warns Study

The effects of climate change may extend beyond the digestive system, affecting multiple aspects of health.

“Global warming is not just affecting how we feel; it's also having an effect on heart disease, lung disease, gastrointestinal disease, obstetrics and gynaecology,” said Metz, who is also the former president of the WGO.

Olano also pointed to population movements as a factor to consider when assessing environmental and health risks.

“As you know, it's not only about weather and climate change. It's also about how populations move from one country to another and what the impact of these movements is when people move from one region to another.”

“Because, as you know, it's not only about weather and climate change. It's also how populations move from one country to another and what the impact of these movements is when people move from one region to another.”

Understanding these connections is important as researchers investigate how climate-related environmental changes may influence disease patterns across regions.

What Can People Do To Protect Their Digestive Health?

While individuals cannot control climate-related changes, Olano highlighted everyday measures that can help prevent infections and support digestive health:

• Drink safe, clean water.
• Maintain food hygiene and handle food safely.
• Wash hands before eating.
• Follow a varied diet.
• Stay physically active.

She also stressed the importance of seeking medical advice about hepatitis prevention, vaccination and testing where appropriate, as well as colorectal cancer screening.

Climate change presents a broader public health challenge, but safe water, food hygiene and infection prevention remain important measures for reducing avoidable digestive health risks.

Depression affects millions of people worldwide, but not everyone responds equally well to treatment. Now, researchers at the University of Sydney have identified a new subtype called “circadian depression,” which is linked to the body’s internal clock and may help explain why conventional antidepressants work less well for some people.

The subtype was identified in nearly a quarter of participants with severe, recurrent or persistent depression in an Australian study. Researchers say recognizing its characteristics could help clinicians identify patients who may benefit from different treatment approaches.

“Our research has identified circadian depression as a new subtype, affecting around a quarter of people in our study into those with severe, recurrent or persistent depression,” said Dr. Emiliana Tonini from the Brain and Mind Centre at the University of Sydney.

“Depression is not a uniform illness and understanding the characteristics of different subtypes mean that we can give people earlier access to treatments that will be most effective for them,” she added.

Circadian Depression: What Are The Key Symptoms?

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Circadian depression is linked to the body’s 24-hour internal clock, which regulates the sleep-wake cycle. Researchers identified several symptoms and characteristics associated with this subtype, including:

• A seasonal pattern of illness

• Sleeping longer during depressive episodes

• Waking up feeling very tired

• Being a night owl

To investigate the subtype, researchers analyzed clinical and genetic data from more than 10,000 people with depression who participated in the nationwide Australian Genetics of Depression Study.

Of these, 2,604 participants, or nearly 25%, were identified as having circadian depression.

The researchers also found that people with this subtype were more likely to experience depression earlier in life and had more severe symptoms, including mania and higher levels of suicidal thoughts.

In addition, these participants had a higher genetic risk for inflammatory and cardiovascular health problems, as well as major neurodevelopmental disorders, including attention-deficit/hyperactivity disorder (ADHD).

The findings, published in the British Journal of Psychiatry, offer insights into the genetic mechanisms associated with circadian depression and may help explain why conventional treatments, such as selective serotonin reuptake inhibitors (SSRIs), work less well for some people with this subtype.

How Does Circadian Depression Differ In Treatment Response?

Antidepressants such as SSRIs and serotonin-norepinephrine reuptake inhibitors (SNRIs) are commonly used to treat depression. However, the researchers reported that these medications were less effective and associated with more side effects in people with the circadian subtype.

Because circadian depression is linked to the body’s internal clock, treatments targeting circadian rhythms may be relevant for some patients. These include light therapy, melatonin and melatonin-targeted antidepressants.

“Because circadian depression is linked to people’s internal body clock, treatments targeting the circadian rhythm, such as light therapy and melatonin, may be much more relevant, and clinicians should reach for these much earlier in people with this presentation,” said Dr. Jacob Crouse, co-senior author of the study, from the Brain and Mind Centre.

“For those who find that antidepressants are not working for them, it is important to speak to your clinician for advice about your individual circumstances,” he added.

Professor Ian Hickie, co-director of the Brain and Mind Centre and a clinical psychiatrist, emphasized that failing to recognize circadian depression in young people could contribute to early treatment failures and more side effects.

“We really want young people to receive the most appropriate treatment early in their course of illness.

“Most young people will be offered SSRIs first up, but for at least a quarter there are better circadian-focused medical and behavioural options to help treat and manage their condition.”

The findings suggest that identifying circadian depression could help clinicians consider more tailored treatment approaches. However, the study does not establish that body-clock disruption causes depression or that every person identified with this subtype will respond better to circadian-focused treatments. Patients should consult their clinicians before making any changes to prescribed medication, the experts said.

In India, breast cancer is the most diagnosed cancer among women and the leading cause of cancer-related deaths in women. According to the International Agency for Research on Cancer’s GLOBOCAN 2024 estimates, the country recorded approximately 237,231 new cases and 96,100 deaths. Across both sexes, it is the second leading cause of cancer death.

The median age of diagnosis among Indian women is 51, nearly a decade younger than in most developed countries. One hospital-based study estimates that 25% of cases occur in women under 40, underscoring the importance of breast awareness, timely symptom evaluation, clinical examination and individual risk assessment. The Breast Imaging Society of India recommends mammography screening from age 40, considering individual risk and available resources.

Breast cancer risk does not suddenly begin at a particular birthday, and two women of the same age may have very different risk profiles. Women should be encouraged to become familiar with the usual appearance and feel of their breasts and to seek prompt clinical evaluation for unexplained breast changes. In India, where breast cancer often presents at a comparatively younger age and access to high-quality imaging is uneven, discussions about early detection should extend beyond age alone. Family history, inherited susceptibility, previous breast findings and other recognized risk factors can help determine whether a woman may benefit from earlier assessment, specialist referral or additional imaging.

Why individual risk matters

A risk-informed approach should consider several factors:

• Family history: Breast or ovarian cancer in close relatives, particularly diagnoses at younger ages, cancer affecting both breasts, male breast cancer, or multiple affected relatives may indicate inherited susceptibility. This may warrant earlier risk assessment before age 40.

• Genetic factors: Women with BRCA1 or BRCA2 gene variants may also require earlier than average-risk screening, starting as early as age 25.

• Breast density: Dense breast tissue can lower the sensitivity of mammography and is independently associated with breast cancer risk. Supplemental imaging such as MRI may be considered in selected women, based on the overall risk, the quality of available imaging and the potential for false-positive results and unnecessary biopsies.

• Previous breast findings: A previous high-risk breast lesion, atypical biopsy result or suspicious imaging finding may change the recommended screening frequency or method. Women with such findings should follow an individualized plan developed with their physician.

Also read: Breast Cancer: Are Women in India Being Diagnosed Too Late?

Persistent inequalities in access

Access to breast assessment, imaging and specialist interpretation remains highly unequal across India. The lifetime prevalence of breast cancer examination is only 8.8 per 1,000 women, with uptake varying by education, economic status and geography. High uptake among educated, affluent, and urban women, especially in southern India, highlights how social determinants and health system barriers shape access to breast cancer screening. India also faces shortages and maldistribution of imaging specialists, with approximately one radiologist per 100,000 people, compared with one per 10,000 in the US. Specialists are disproportionately concentrated in urban areas.

Addressing these inequalities requires more than awareness campaigns. Priorities include strengthening clinical breast examination and referral pathways, training frontline health workers, expanding access to diagnostic imaging and pathology, ensuring timely follow-up after abnormal findings, and monitoring outcomes across socioeconomic and geographic groups.

Also read: World Breast Cancer Day 2026: Life After Breast Cancer, The Fear No One Sees

Where artificial intelligence could support early detection

Artificial intelligence (AI) is being evaluated as a potential support for breast cancer detection in settings where imaging capacity and specialist availability are limited. Depending on the technology and clinical context, AI may assist with triage, image interpretation, workflow prioritization or risk estimation. Its clinical value depends on appropriate validation, reliable referral pathways, diagnostic confirmation, quality assurance and ongoing monitoring for unequal performance across population groups.

Integrating community health workers, portable AI technology and digital referral pathways within primary health care could potentially help reach women who face geographic, financial or health-system barriers. The most important feature is not the algorithm alone, but the complete pathway linking awareness, initial assessment, referral, diagnostic confirmation and treatment. AI output is not a diagnosis. It must be interpreted alongside the patient’s clinical history, risk factors, examination findings and appropriate diagnostic imaging.

Translating personal risk into informed screening decisions

For women, a more personalized approach does not mean performing more tests in every case. It means identifying those who may benefit from earlier, more frequent or different forms of assessment while avoiding unnecessary imaging and procedures among women unlikely to benefit.

As part of a shared decision-making conversation, women may wish to ask their physician:

• Based on my age and personal risk factors, when should breast cancer screening begin?
• Does my family history suggest that I need a formal risk assessment?
• Would referral for genetic counselling be appropriate for me?
• If I have dense breasts, how does that affect the interpretation of my mammogram and my overall risk?
• Do previous breast symptoms, imaging findings or biopsy results change my follow-up plan?
• Which screening or diagnostic services are available locally, and what follow-up will be provided if an abnormality is found?
• Would a formal breast cancer risk-assessment help guide my screening plan?

Breast Cancer Awareness Month is an opportunity to advocate for equitable care pathways, from risk assessment and early detection to diagnosis and timely treatment. In India, a key challenge is ensuring every woman with a concerning symptom or abnormal finding receives appropriate assessment, diagnostic confirmation and treatment without avoidable delays.

Preparing future physicians for evolving healthcare needs is central to medical and public health education at St. George’s University School of Medicine. Through a diverse, international learning environment and clinical exposure, students develop the medical knowledge, clinical skills and professional competencies needed to care for diverse patient populations.

By Dr. Tonia Frame, Assistant Professor and Director of the Global Health Unit in the Department of Public Health and Preventive Medicine at St. George’s University