New Delhi: Early-onset diabetes, hearing loss, physical inactivity and undernourishment are among the most significant modifiable risk factors contributing to dementia in India, according to a new study reviewing 25 years of research on dementia prevalence and associated health risks.
The study, led by researchers from Rutgers University in the United States and published in the journal Alzheimer’s & Dementia, analysed research conducted among the Indian population between 2000 and 2025. The review assessed the prevalence of dementia in India and examined how various lifestyle and health factors influence the risk of developing the condition.
Researchers said identifying and addressing these risk factors could help delay or prevent a substantial proportion of dementia cases.
Women and rural populations more affected
The study found that, similar to trends observed in many Western countries, dementia is more prevalent among women in India.
Researchers also reported a higher prevalence of dementia among people living in rural areas, which they believe may partly be due to the underdiagnosis and inadequate management of conditions that increase dementia risk.
They stressed that improving access to healthcare and early screening in rural communities could help identify risk factors before cognitive decline develops.
Diabetes a major contributor
Among the strongest risk factors identified was diabetes, particularly because South Asians tend to develop the condition at a younger age and often at lower body weights than many other populations.
According to the researchers, diabetes can double or even triple the risk of developing dementia.
India is among the countries with the highest number of people living with diabetes, alongside China and Pakistan, making effective diabetes prevention and management a key public health priority.
Experts say maintaining healthy blood sugar levels through balanced nutrition, regular physical activity and appropriate medical treatment may also contribute to better long-term brain health.
Hearing loss linked to higher dementia risk
The review also identified hearing loss as an important and potentially preventable risk factor.
Researchers found that hearing impairment, which affects around 41 per cent of adults in India, was associated with a 59 per cent higher risk of developing dementia and nearly double the risk of Alzheimer’s disease.
They noted that timely diagnosis and treatment of hearing problems through hearing aids or other interventions may help reduce cognitive decline in some individuals.
Physical inactivity raises concern
The study highlighted physical inactivity as another significant modifiable risk factor.
Researchers cited evidence showing that as little as 35 minutes of physical activity per week is associated with a 41 per cent lower risk of dementia.
Despite this, around 57 per cent of Indian adults do not meet recommended levels of physical activity.
Healthcare experts continue to recommend regular exercise as part of a healthy lifestyle, noting that physical activity benefits both cardiovascular and brain health.
Undernutrition also plays a role
Unlike many Western countries, where obesity is considered a major contributor to dementia risk, researchers found that being underweight and undernourished also appears to increase the likelihood of developing dementia in India.
They said nutritional deficiencies may affect brain function and overall health, underscoring the importance of balanced nutrition throughout life.
Education and vision impairment identified
The review also identified limited education and untreated vision impairment as notable risk factors.
According to the findings, limited education accounts for around 22 per cent of modifiable dementia risk in India, compared with 8 per cent globally.
Untreated vision loss was estimated to contribute to approximately 14 per cent of dementia cases in the country.
Researchers said improving access to education and timely eye care could play an important role in reducing future dementia burden.
Need for long-term research
The findings have paved the way for the South Asian Middle Age Risk Tracking for Brain Health (SAMARTH) study at Rutgers University, which aims to investigate brain health among South Asian populations and identify both risk and protective factors associated with Alzheimer’s disease and related dementias.
Researchers concluded that more longitudinal studies are urgently needed to better understand dementia in the Indian population and to develop effective prevention strategies.
They added that addressing modifiable risk factors through early intervention, improved healthcare access and healthier lifestyles could significantly reduce the future burden of dementia in India.