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Stress is an unavoidable part of life, and while it often carries a negative connotation, it is actually a fundamental survival mechanism. When faced with a perceived threat, whether physical or emotional, the body instinctively reacts to protect itself. This automatic response is commonly known as the "fight, flight, or freeze" response. While it serves an essential function in dangerous situations, chronic activation of this response due to daily stressors can have significant consequences for mental and physical health.
The body’s response to stress is rooted in human evolution. When our ancestors encountered a predator, their nervous systems immediately prepared them to either confront the threat (fight), escape to safety (flight), or become still and unnoticed (freeze). While modern-day stressors may not include wild animals, our nervous system reacts similarly to job pressures, financial worries, or social conflicts.
According to the Cleveland Clinic, stress is the body's response to change, activating a physiological reaction that helps us adapt and protect ourselves. While short-term stress can be beneficial, prolonged exposure can lead to an overactive stress response, negatively impacting overall well-being.
The fight response prepares the body for direct action. When triggered, the nervous system releases adrenaline, increasing heart rate, blood pressure, and muscle tension. While this reaction once helped early humans fend off predators, today it manifests as irritability, frustration, or aggression.
For instance, the employee who has experienced too much workload may work extremely long hours just to succeed. In short term, the action may produce good results but mostly ends in burnout, anxiety, and physical illness, for example, tension headache or digestion problems.
The flight response triggers an intense need to remove oneself from a stressful situation. Just as our ancestors would flee from danger, modern individuals may avoid conflict, quit jobs impulsively, or detach from relationships when overwhelmed.
Flight mode is linked with restlessness and anxiety. Individuals may have a sense of needing to get up and go-pacing, changing environments constantly, or avoiding tasks that seem too overwhelming. Someone with a flight response might have the desire to change jobs constantly, relocate constantly, or become reclusive in order to avoid perceived dangers.
The freeze response occurs when the nervous system perceives a threat as too overwhelming to fight or flee. Rather than taking action, individuals shut down, feeling numb, disconnected, or paralyzed by fear.
Unlike fight or flight, which involve heightened activation, freeze mode slows down physiological functions. A person experiencing freeze mode may feel physically unable to move, struggle to make decisions, or find themselves dissociating from their emotions. This can manifest in situations such as public speaking anxiety, where someone might "blank out" or feel stuck in the moment.
When faced with a stressor, the autonomic nervous system (ANS) activates, triggering physiological changes, including:
For those experiencing the freeze response, the body undergoes a different reaction, often reducing heart rate and causing physical immobility rather than heightened activation.
While the stress response is necessary for survival, frequent activation due to daily stressors can take a toll on health. Recognizing your default response—whether fight, flight, or freeze—can help in developing effective coping mechanisms.
If possible, changing your environment can help signal to your brain that the threat has passed. Stepping outside for fresh air, finding a quiet place, or distancing yourself from overwhelming stimuli can help regulate emotions.
Deep, slow breathing can be used to counteract the stress response by engaging the parasympathetic nervous system, which promotes relaxation. Techniques such as diaphragmatic breathing or the 4-7-8 method (inhale for four seconds, hold for seven, exhale for eight) can be particularly effective in calming the body.
This helps release pent-up energy and aids in the endorphin cascade, natural boosters for our mood.
Relieving oneself from stress can come in many ways, but sharing it with trusted friends, a family member, or a good therapist will sure give that psychological boost of hope. Social support is an especially effective way of cushioning people against the stressors that they are subjected to in chronic forms.
While occasional stress is normal, chronic activation of the fight, flight, or freeze response can indicate underlying mental health concerns, such as anxiety disorders or post-traumatic stress disorder (PTSD). If stress is affecting daily life—leading to sleep disturbances, difficulty concentrating, or persistent feelings of fear—it may be time to consult a mental health professional.
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Through the first quarter of the twenty-first century, it has been clear that the global menace of infectious diseases has become very different in terms of their causal factors and predictability.
A 2022 review in Nature Reviews Microbiology by Princeton professors Rachel Baker and Jessica Metcalf aptly pointed out how climate change, urbanization, and wider travel and trade determine when, where, and how outbreaks of infections happen. Examples of such outbreaks are numerous globally, viz. SARS, H1N1, MERS, Ebola, Zika, and COVID-19 outbreaks. It has also been realized by biomedical scientists that more than half of all known pathogenic diseases have at some point been worsened by climate-change-related events.
As a result, research on climate-disease links has surged since the recent pandemic.
Evidence supporting this climate-disease relationship is also abundant in the Indian context. A major example is our experience with dengue infections, which are clearly losing their seasonal predictability. Contrary to its usual temporal link with the monsoon, India has encountered an unusually early transmission in 2026, with nearly 7,000 cases reported by end-February, as per the National Center for Vector-Borne Diseases Control data. The vector has also expanded its geographical distribution, for example into Himalayan towns such as Darjeeling over the past decade.
Meanwhile, the Integrated Disease Surveillance Program in India also reports bimodal waves of influenza transmission and infections with respiratory syncytial virus (RSV) surge during the monsoon. These provide evidence that overlapping and compressed disease seasons are becoming more common.
Warming temperatures and erratic rainfall alter mosquito breeding cycles and pathogen incubation periods, while floods can create sudden transmission spikes in a population. On the other hand, rapid urbanization increases overlap among human, animal, and vector habitats. India is expected to have an urban population of close to 600 million by 2031. This will further intensify livestock density, land-use change, and human-wildlife contact, raising the risk of zoonotic spillovers.
As is evident globally now, global travel and trade will carry the pathogens across borders way faster than health systems can respond. Thus, reactive outbreak responses, of testing, isolating, and reporting only after cases show a surge, are strategically too slow. However, genomic and wastewater surveillance offer scalable alternatives. For example, such efforts in India could detect SARS-CoV-2 variants in sewage much before case counts rose in a population.
Similar experience has been gathered in cities like Bengaluru, wherein wastewater monitoring could track influenza and RSV circulation independent of individual testing. Artificial intelligence and machine learning models further add to the forecasting capacity. Modelling climate, land-use, and animal-movement data can flag likely zoonotic spillover risks well before an outbreak begins.
India's national zoonotic disease prioritization exercise and state-level One Health pilot studies in Gujarat and Rajasthan show that human, veterinary, and environmental data must be integrated. Such interdisciplinary cohort research, tracking populations across seasons and geolocations, can achieve usable forecasts integrating discrete data. Thus, building such predictive, One Health-oriented research and surveillance infrastructure will be imperative for India to achieve optimal pandemic preparedness.
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It has been long suspected that Western diets could contribute to the risk of colorectal cancer. The theory may finally have a clearer scientific explanation.
A new study suggests that gut bacteria can convert compounds produced by high-fat, low-fibre diets into cancer-causing chemicals. The research sheds light on how unhealthy eating habits may lead to cancerous tumour growth in colon in the long term.
Published in the journal Gut, the research was led by Dr. Annika Osswald (first author) and Dr. Soeren Ocvirk (corresponding author), along with a large team of international scientists.
The collaboration included researchers from Technical University of Munich (TUM), Germany, German Institute of Human Nutrition (DIfE), RWTH Aachen University, Freie Universität Berlin, University Hospital of Regensburg, and other institutions.
Researchers found that a western-style diet, which is commonly high in red and processed meat, saturated fats, refined carbohydrates and ultra-processed foods, significantly changes the composition of the gut microbiome.
These altered bacteria then modify bile acids in ways that promote inflammation and create an environment that accommodates the development of colorectal cancer tumours.
According to the researchers, diet alone is not the only factor. The trillions of microbes living in the intestine determine how food is processed, producing metabolites that can either protect the gut or damage it.
The study found that specific bacterial groups transformed bile acids into compounds that stimulated tumour growth in the colon.
This provides one of the strongestt explanations yet for why western dietary patterns have consistently been associated with higher risk of colorectal cancer.
"Our findings highlight the critical interaction between diet, gut microbes and cancer biology," the researchers noted, adding that targeting the microbiome could become a future strategy for preventing colorectal cancer.
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A western diet typically includes:
Previous research has repeatedly linked this eating pattern with obesity, diabetes, heart disease and colorectal cancer, but scientists have long found it challenging to explain the exact cause until now.
The human gut is home to trillions of bacteria that help digest food, regulate immunity and produce beneficial compounds like fatty acids.
A fibre-rich diet supports good bacteria that reduce inflammation, whereas diets high in fat and processed foods can cause microbial imbalance.
The new findings suggest this imbalance changes how bile acids are metabolised, increasing the production of molecules capable of damaging the colon and supporting cancer growth in the long run.
Also read: WHO Cancer Agency Flags 3 Common Medicines As Carcinogenic: What It Means For Millions Of Patients
Earlier research has linked harmful gut bacteria, including toxin-producing E. coli, with DNA damage that may begin early in life and contribute to the rise of colorectal cancer among younger people.
However, the latest findings do not prove diet alone causes cancer. Genetics, obesity, physical inactivity, sedentary life, smoking and alcohol consumption also influence risk.
However, they say maintaining a fibre-rich diet with fruits, vegetables, legumes and whole grains may help preserve a healthier gut microbiome and lower long-term colorectal cancer risk.
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Could air pollution may do more than harm the lungs and heart? A new study has found that exposure to polluted air could trigger painful flare-ups in people living with rheumatoid arthritis (RA).
The study comes when evidence is mounting that environmental factors contribute significantly to autoimmune diseases.
The study, published in the Annals of the Rheumatic Diseases, found that excessive exposure to air pollutants, particularly fine particulate matter (PM2.5), was associated with increased rheumatoid arthritis activity and a greater risk of flare ups.
Researchers say the findings suggest that improving air quality should become an important part of managing the chronic condition, alongside treatment, medications and lifestyle changes.
"Our findings highlight that environmental exposure, especially air pollution, may significantly influence rheumatoid arthritis disease activity and flare risk," the researchers said, noting that patients and clinicians should consider air quality as a modifiable risk factor.
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Rheumatoid arthritis is an autoimmune disease in which the immune system attacks healthy joints, causing pain, swelling, stiffness and, over time, permanent joint damage.
While genetics, smoking and infections have been recognised as risk factors, scientists are investigating how environmental pollutants may worsen the disease.
The latest findings are particularly relevant for countries such as India, where millions are exposed to unhealthy air for large parts of the year. Previous reports have already linked poor air quality in cities like Delhi to rising concerns over autoimmune diseases.
Also read: Severe COVID-19 Can Reactivate Dormant Viruses, May Fuel Long COVID Symptoms: Study
A flare is a period when rheumatoid arthritis symptoms suddenly worsen. During this time, people may experience:
Flares can last from a few days to several weeks and are often triggered by infections, stress, missed medications or other environmental factors.
Researchers believe tiny airborne particles like PM2.5 can enter the lungs and bloodstream, triggering inflammation throughout the body.
This inflammatory response may overstimulate the immune system, making rheumatoid arthritis symptoms worse and increasing the likelihood of painful flare-ups.
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The researchers emphasised that the study shows an association rather than proving that air pollution directly causes rheumatoid arthritis flares.
However, the consistent link suggests reducing exposure to polluted air may help lower the chances of flare-ups in high-risk individuals.
Experts advise patients to continue prescribed medications, constantly monitor local air quality, avoid outdoor activities during periods of severe pollution when possible, and discuss symptom changes with their rheumatologist.
The findings add to a growing body of research linking air pollution with autoimmune diseases.
Earlier studies have suggested that long-term exposure to pollutants may increase the risk of developing rheumatoid arthritis, while the new research indicates polluted air may also worsen symptoms in people already living with the disease.
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