People over 50 years of age had a 50 per cent faster decline in cognitive functions during the first year of the COVID-19 pandemic than earlier, finds a study.

Alarmingly, this was the case even if the adults didn't have COVID-19.

However, the figure was higher in those who already had mild cognitive decline before the pandemic, according to the research published in The Lancet Healthy Longevity.

Researchers looked at results from computerised brain function tests from more than 3,000 participants, who were aged between 50 and 90 and based in the UK.

The study checked the participants' short-term memory and ability to complete complex tasks. They found that cognitive decline quickened 50 per cent significantly in the first year of the pandemic.

This continued into the second year of the pandemic, suggesting an impact beyond the initial 12-month period of lockdowns.

The researchers believe this sustained impact to be particularly relevant to ongoing public health and health policy. The cognitive decline seems to have been exacerbated by a number of factors during the pandemic, including an increase in loneliness and depression, a decrease in exercise, and higher alcohol consumption.

Previous research has found that physical activity, treating existing depression, getting back into the community, and reconnecting with people are all important ways to reduce dementia risk and maintain brain health.

"Our findings suggest that lockdowns and other restrictions we experienced during the pandemic have had a real lasting impact on brain health in people aged 50 or over, even after the lockdowns ended. This raises the important question of whether people are at a potentially higher risk of cognitive decline which can lead to dementia," said Anne Corbett, Professor of Dementia Research at the University of Exeter.

"It is now more important than ever to make sure we are supporting people with early cognitive decline, especially because there are things they can do to reduce their risk of dementia later on. So if you are concerned about your memory, the best thing to do is to make an appointment with your GP and get an assessment. Our findings also highlight the need for policymakers to consider the wider health impacts of restrictions like lockdowns when planning for a future pandemic response," she added.

Currently, dementia affects about 50 million people worldwide and is projected to triple by 2050. The researchers called for lifestyle changes and improved health management to positively influence mental functioning.