According to an elongated study conducted at the University of Washington, air pollution raises the risks of dementia, lending fears that the bulk of India’s population could be rendered far more prone to developing the condition.
The study used data from two long running datasets — one that began in the late 1970s charting air pollution changes and another on risk factors for dementia that began in 1994 — and found that even a small increase in the levels of PM2.5 (particulate matter 2.5 micrometres or smaller) averaged over a decade at specific addresses in the Seattle area was associated with a greater risk of dementia.
“We found that an increase of one microgram per cubic meter of exposure corresponded to a sixteen percent greater hazard of all-cause dementia. There was a similar association for Alzheimer’s-type dementia,” said lead author Rachel Shaffer, who conducted the research as a doctoral student in the University of Washington Department of Environmental and Occupational Health Sciences.
The study looked at more than 4,000 Seattle-area residents enrolled in the Adult Changes in Thought (ACT) Study run by Kaiser Permanente Washington Health Research Institute in collaboration with the University of Washington. More than 1,000 of these individuals have since been diagnosed with dementia. The study assessed all residents and compared the pollution levels of their address for the decade prior to their diagnosis. “We know dementia develops over a long period of time. It takes years – even decades – for these pathologies to develop in the brain, and so we needed to look at exposures that covered that extended period,” Shaffer said.
The capacity to study the effects of pollution levels over a period of more than forty years is all but unprecedented, and offers an invaluable insight into the effects of pollution on the development of dementia. In recent years our understanding of the effects of air pollution on the body have improved drastically. While previously it was largely assumed that air pollution was only responsible for respiratory pathologies, it is now known that the particulate matter is absorbed through the lungs and into the blood. As a result of the inflammation this causes, numerous conditions are exacerbated, or are caused by the effects, such as heart disease, diabetes, and now, dementia.
India remains top of the list of the world’s air pollution hotspots. This new study presents an ever more dire picture of the effects this is having on the Indian population. For many who have dwelled within an urban, “smog chamber” environment for their whole lives, there lies a grave potential for either a life cut tragically short, or for chronic conditions such as dementia and diabetes to take their toll on them, as well as their family.
Dr Amit Dias, a lecturer at the department of Preventive and Social Medicine at Goa Medical College (GMC) and one of the authors of the Lancet study entitled “40% of dementia cases could be prevented or delayed by targeting 12 risk factors throughout life”, previously provided Health Issues India with a greater insight into the situation in India regarding dementia and neurodegenerative conditions. Dias said
“With the demographic transition, the numbers of people with dementia are rising very rapidly in the low and middle income countries such as India. India is a large country, so though we have a comparatively younger population, in terms of total numbers we are estimated to have around four million people with dementia in the country. Moreover, it’s a myth to say that we are equipped to deal with the situation. We had done a study on the care arrangements for people with dementia and it revealed that due to stigma and lack of awareness more than ninety percent of the people with dementia in India do not even get a diagnosis and deal with the condition without a clue, and this adversely affects the life of the person with dementia as well as the caregivers. Yes, our strength is that people with dementia are still looked after by their families, but with the family structure breaking down, people are finding it difficult to cope and this often leads to abuse and a tremendous amount of caregiver burnout.”
Alzheimer’s disease, as well as other forms of dementia, are a group of conditions for which the risk is increased with age. India is home to an ageing population – a statistic that is a double-edged sword. On the one hand, it is undoubtedly good that life expectancy is increasing thanks to advances in medical technology, healthcare, diagnostics, and treatments. On the other hand, it means that rates of conditions such dementia have increased – necessitating awareness and support for both patients and their loved ones.
This combination of an aging population, as well as both urban and rural individuals growing up in an environment where they may very rarely see pollution levels drop to a safe level, has formed a ticking time bomb. Dementia cases in India are already rising. According to the Alzheimer’s Association, “in India, more than four million people have some form of dementia.” By 2030, the number is projected to rise to 7.6 million. In the future beyond 2030, a combination of an aging population, along with individuals who were born and have grown up following India’s rapid industrialisation that saw pollution levels skyrocket will likely see these numbers swell to unprecedented levels.
