Experts emphasize that environmental toxicity does not act in isolation. Chronic exposure combined with poor air quality, sedentary lifestyles, and metabolic diseases can create a “perfect storm” for brain degeneration.
Published Oct 03, 2025 | 7:00 AM ⚊ Updated Oct 03, 2025 | 7:00 AM
Synopsis: Dementia affects individuals physically, psychologically, socially, and economically, impacting both those living with it and their carers, families, and society. Limited awareness often leads to stigma and barriers to diagnosis and care, WHO notes.
India is confronting a silent but fast-approaching epidemic: dementia. Once brushed aside as the natural decline of old age, dementia, which includes conditions such as Alzheimer’s, Parkinson’s-related cognitive decline, and other neurodegenerative disorders, is now rising in alarming numbers with younger patients increasingly showing symptoms.
According to the Longitudinal Aging Study in India (LASI), the estimated prevalence of dementia among adults aged 60 and older in India is 7.4 percent, equating to approximately 8.8 million individuals currently living with dementia.
If this prevalence remains constant, demographic aging alone is projected to increase this number to about 16.9 million by 2036, effectively doubling the dementia burden within a little over a decade.
Meanwhile, India is projected to experience a significant surge in Parkinson’s disease (PD) cases by 2050. According to a study published in The BMJ, the global number of people living with PD is expected to reach 25.2 million by 2050, marking a 112 percent increase from 2021.
In India, the prevalence is anticipated to rise by 168 percent , with approximately 2.8 million individuals affected, accounting for 10 percent of the global burden.
At the same time, in cities like Bengaluru, where studies have already detected dangerous levels of heavy metals like manganese and nickel in the air, the environmental risks compound the crisis.
According to the World Health Organisation (WHO), Dementia is a syndrome caused by various diseases that gradually destroy nerve cells and damage the brain, leading to cognitive decline beyond normal ageing.
Consciousness remains unaffected, but cognitive impairment is often accompanied, or sometimes preceded, by changes in mood, behaviour, or motivation.
Dementia affects individuals physically, psychologically, socially, and economically, impacting both those living with it and their carers, families, and society. Limited awareness often leads to stigma and barriers to diagnosis and care, WHO notes.
It is an umbrella term encompassing a range of neurodegenerative disorders, including Alzheimer’s disease, which affects memory, and Parkinson’s, which can impair both movement and cognition.
India is entering what experts are calling an “age of dementia,” as cases of memory loss and neurodegenerative disorders rise at a pace the healthcare system is unprepared for.
“Dementia is no longer just a medical condition, it reflects a larger social and environmental crisis,” said Dr Srividhya S, Associate Consultant in Neurology at Rela Hospital, Chennai.
She explained that urban centres like Bengaluru are witnessing sharper increases because of factors ranging from stress-filled routines to worsening air quality. Families often misread dementia symptoms as “normal ageing,” delaying diagnosis and treatment.
Parkinson’s disease is becoming the fastest-growing contributor. “The worldwide prevalence of Parkinson’s is expected to double by 2040, outpacing even Alzheimer’s,” said Dr. Akhil Raj, Neuro & Spine Surgeon at the Nonpareil Centre for Neuro and Psychosomatic Development.
The impact, he warned, will not be confined to the elderly. With rising environmental triggers and changing lifestyles, “We may see many productive citizens in their 30s and 40s suffering from Parkinson’s or dementia in the next two decades.”
While dementia is often associated with older adults, an increasing number of younger people are being diagnosed with the condition. Known as Young-Onset Dementia (YOD), it refers to dementia whose symptoms appear before the age of 65.
Dr. Ravi Kumar K, Consultant, Neurology, MGM Healthcare, Chennai, explained, “Young-onset dementia refers to dementia whose symptoms appear before 65 years of age,” and added that, “Though it’s much less common than dementia in older age, its impact is large: affecting work, family, finances, caregiving roles over many potentially productive years and delays in diagnosis and misdiagnosis are frequent.”
Scientific studies indicate that among people aged 30–64, “The prevalence of young-onset dementia is approximately 120 per 100,000, corresponding to about 3.9 million people worldwide,” said Dr. Ravi Kumar.
“New cases for people aged 30–64 occur at a rate of approximately 11 per 100,000 person-years, with incidence increasing sharply as age nears 65,” he added.
YOD often presents differently than dementia in older adults. Dr Ravi Kumar noted that younger patients may show non-memory symptoms early, such as language problems, visual-spatial disorientation, or behavioural changes, rather than classic memory loss.
Psychiatric or neuropsychiatric features, changes in mood, behaviour, or personality, can be misattributed to stress or psychiatric illness, leading to diagnostic delays. “Symptoms in younger people are often overlooked or attributed to other causes, delaying interventions,” he said.
Emerging research offers hope for early detection. “New blood biomarkers such as tau-217, NfL, and GFAP are showing promise to predict dementia years before symptoms develop,” Dr. Ravi Kumar said.
Trials are underway to integrate blood tests for Alzheimer’s pathology (e.g., p-tau217) into broader clinical use, potentially allowing interventions even in younger patients.
Regarding therapies, Dr. Ravi Kumar added: “Some of the newer Alzheimer’s drugs targeting amyloid (a type of protein linked to Dementia), such as lecanemab, have been approved for early Alzheimer’s disease and could eventually be relevant for younger-onset cases if used early. Research into non-amyloid/tau pathways, inflammation, vascular risk, and lifestyle modifications offers hope to alter disease course rather than just manage symptoms.”
Looking ahead, Dr. Ravi Kumar emphasized the need for a multi-pronged approach: “Increasing awareness among healthcare providers that dementia is not just an old-age disease is important. Young people with cognitive, behavioural, or psychiatric symptoms should be assessed for YOD when appropriate.”
He also highlighted the importance of structured evaluation: “Developing guidelines for evaluation of younger patients, including more thorough workup, neuroimaging, and specialist teams is essential.”
On the diagnostic front, he added, “Expanding blood-based biomarkers and simpler diagnostic tools that can be used more widely and early should be focused.”
Finally, he stressed, “Strengthening support systems, such as financial, workplace, caregiver, psychosocial, and legal, and tailoring services such as housing and counselling for younger people,” should be looked into.
While ageing and lifestyle changes contribute to dementia, environmental factors are increasingly recognized as critical triggers.
Heavy metals such as manganese, nickel, lead, and mercury are known to be neurotoxic, accumulating in the brain and triggering oxidative stress and inflammation.
“These metals can disrupt brain function, potentially accelerating cognitive decline and even contributing to Parkinson’s and Alzheimer’s,” explained Dr. Srividhya
Bengaluru presents a stark example of this risk. A 2019 study titled Choking in the Garden City, conducted across 27 locations in the city, revealed that airborne manganese levels exceeded WHO guidelines in several areas, while nickel and crystalline silica were alarmingly high in most samples.
Air purifiers have also been used to trap and analyze pollutants, confirming the presence of manganese and other neurotoxic metals in Bangalore’s air.
Dr. Akhil Raj warned, “Excessive exposure to metals like manganese can impair dopamine-producing neurons, increasing the risk of Parkinson’s disease and other neurodegenerative disorders.”
Manganese, although an essential nutrient in small amounts, can become toxic at higher levels. It interferes with cellular mechanisms in the brain, leading to oxidative stress, mitochondrial dysfunction, and neuronal death.
Noting that this dual nature makes urban exposure particularly hazardous, the doctor added, “While occupational or environmental exposure—such as in mining, welding, or industrial settings—can significantly increase health risks, dietary exposure alone is generally considered safe.”
He further pointed out that, high-risk occupations such as battery manufacture, organo-chemical fungicide use, and ore processing can further increase exposure to neurotoxic metals, putting workers at heightened risk for cognitive decline and Parkinson’s disease.
Experts emphasize that environmental toxicity does not act in isolation. Chronic exposure combined with poor air quality, sedentary lifestyles, and metabolic diseases can create a “perfect storm” for brain degeneration.
Dr. Srividhya added, “Understanding and mitigating environmental exposure is as important as lifestyle modification in protecting cognitive health, particularly in industrial urban centres like Bengaluru.”
Sedentary lifestyles, poor diets, chronic stress, and unmanaged medical conditions like diabetes, hypertension, and heart disease amplify the risk. “These chronic diseases damage blood vessels and, when combined with environmental toxins, accelerate cognitive decline,” explained Dr. Srividhya.
Lifestyle modifications can help counteract these risks. Regular physical activity, antioxidant-rich diets, proper sleep, stress reduction, and maintaining social connections strengthen brain and vascular health. “Even in polluted urban settings, adopting protective measures can buffer the brain against environmental and metabolic stress,” she added.
Dr. Akhil noted that these lifestyle and environmental factors interact at a cellular level. Heavy metals can exacerbate oxidative stress, mitochondrial dysfunction, and neuroinflammation, while poor metabolic health weakens the brain’s resilience.
This combination increases vulnerability to both Parkinson’s and Alzheimer’s disease, demonstrating how intertwined lifestyle and environmental exposures are in shaping neurological outcomes.
Beyond medical implications, dementia imposes a profound social and economic burden.
Families often become primary caregivers, navigating daily care, medications, and mobility challenges, all while confronting stigma and a lack of support. “Families frequently misinterpret dementia as normal ageing, delaying treatment and increasing emotional strain,” said Dr. Srividhya.
“Moreover, screening tools like cognitive assessments, neuroimaging, and biomarker tests exist but are not widely accessible. Community-level programs could play a critical role in detecting dementia and heavy metal-related neurological risks earlier, especially in urban areas,” she added.
Experts warn that India’s healthcare system is ill-prepared for the coming surge. Dr. Akhil emphasized that urban centres like Bengaluru, with rising heavy metal exposure, face a looming crisis of Parkinson’s and dementia in the 30–50 age group.
Addressing this requires comprehensive action: stricter environmental regulations, national registries to track neurotoxic exposures, public awareness campaigns, caregiver support networks, and the expansion of memory and elderly clinics.
“Preventive health, early detection, and environmental regulation are key pillars to curb this emerging wave of dementia,” Dr. Srividhya stressed. Without coordinated action, India risks not only a health crisis but a societal and economic one, affecting millions of families across urban and rural areas.
With dementia robbing not only memory but also productivity and quality of life, the challenge before India is as social as it is medical.
(Edited by Sumavarsha)
