World Alzheimer’s Day: Why are more Indians at risk of developing Alzheimer’s?

The increasing lifespan and very high burden of diseases such as diabetes, hypertension and obesity are expected to “dramatically” increase the prevalence of dementia in India, according to a 2021 Nature study by researchers from the Indian Institute of Science, looking at the changing demography. Dementia is an umbrella term for a group of disorders that lead to impaired memory, decision-making and social skills – Alzheimer’s is one of the most common types of dementia.

The disease usually occurs in people over the age of 65 years with a very small proportion getting early-onset. “Yes, the burden of dementia is on the rise. This is because our population is living longer and it is ageing. When the average life expectancy was less than 50 years, not many had the chance of developing Azheimer’s or other diseases of the old age. Now, more and more people are living to be over 70 years of age, creating a larger pool of population that can get the disease,” said Dr Rajinder K Dhamija, director, Institute of Human Behaviour and Allied Sciences.

The Dementia in India report 2020 estimates that there are 5.3 million people over the age of 60 years living with dementia, with the prevalence projected to increase to 14 million by 2050.

“The government is aware of the magnitude of the problem. Brain health is one of the important components of the 2047 vision for India’s healthcare. What we need to do is train more doctors, nurses, and paramedical personnel to work with and look after the elderly. Other countries are heavily investing in this care sector. This is important for us as well because we are right now in a transitioning society where many elderly live on their own, with their children living abroad. And, we have to plan to be able to take care of them as well,” said Dr Dhamija.

Have the doctors seen an increase in Alzheimer’s incidence after the pandemic?

Dr Achal Kumar Shrivastava, professor of clinical neurophysiology at the All-India Institute of Medical Sciences, estimates a 15 per cent increase in the number of people getting Alzheimer’s, adding that such studies are not available from India. “The way we have been observing cases post pandemic, it seems that the Coronavirus pandemic has unmasked several neuro-degenerative diseases and Alzheimer’s is one of them. Post-Corona, a number of people have also been facing memory impairment,” he said.

Dr Praveen Gupta, Head of the Department of Neurology at Fortis Memorial Research Institute, Gurugram, said that the pandemic lockdown led to significant confinement and isolation of elderly people which broke down their social ties and cultural ties.

“Covid prevented a lot of Alzheimer’s patients from accessing mentally stimulating activities or doing behaviour and socio-culture therapies. This worsened their condition. A lot of elderly people were confined to their homes and continued to deteriorate in terms of their memory and behaviour. Also, a lot of elderly people, who get memory difficulties, are not evaluated in the early stages or get treated because we consider forgetfulness as normal with age. If these people were to be evaluated at the right time, say within three to four years of the disease, we could possibly help them better. Early diagnosis allows us to treat these patients in the window of opportunities when medicines and behaviour therapies may help,” says Dr Gupta.

How does Covid-19 impact the brain and lead to Alzheimer’s?

A recently published small study from Columbia University of patients who died of Covid-19 found similar molecular changes in their brain as seen in Alzheimer’s patients – the researchers said that a type of defective receptor in the neurons led to an increase in a kind of protein in the brain that is the hallmark of Alzheimer’s disease. This, they say, could be the reason Covid-19 patients experience brain fog. Whether contracting Covid pre-disposes people to get Alzheimer’s later in life or not, the researchers are yet to find out.

Another study detailing ways in which Covid-19 may have impacted the brain says that the infection could be leading to small asymptomatic strokes damaging parts of the brain. So the inflammatory response to the viral infection may be promoting the progression of the disease and long hospitalisations, especially ICU care, could result in cognitive impairment.

Dr Gupta said, “There may be an increase in the risk of Alzheimer’s in the elderly people post Covid because it leads to subtle brain damages as reported in several studies. The damage can be either due to lack of oxygen, alternation in blood pressure, causing mini strokes or seizures or just because of the significant psychological morbidity that it imposes on elderly people.”

Several studies have now shown an increased diagnosis of Alzheimer’s after the pandemic, with a large cohort-based study from the United States showing that seven new cases of Alzheimer’s were diagnosed for every 1,000 old people who had Covid-19 as compared to five new diagnosis for every 1,000 among those who did not have the infection.

What should we do to keep Alzheimer’s at bay?

The most important thing, Dr Dhamija says, is to keep the brain active. Just like physical exercise, exercising the brain every day is also important. “Learning new languages, developing hobbies like music, solving puzzles like Sudoku keep the brain active and cognitively fit. It is also important for the elderly to go out, make new friends and socialise,” said Dr Dhamija.

The disease can also be kept at bay by mitigating risk factors such as diabetes, hypertension, and obesity through a good diet, exercise, enough sleep, and doing away with smoking.