According to researchers memory and other brain skills begin to decline at the age of 45. This is much earlier than previously thought.
Researchers from the Centre for Research in Epidemiology and Population Health in France and University College London in the UK studied more than 7,000 people over a 10-year period and show the brain's capacity for memory, reasoning and comprehension starts waning in middle age rather than in the 60s. This study was deemed important because younger people should be encouraged to boost their brain power with healthier living, while some may benefit from medicines to stave off further decline.
Further one in four Britons will be older than 65 by the year 2035 because of the rise in aging populations. Thus doctors claim “cognitive ageing will be one of the challenges of this century”.
The study looked at civil servants aged between 45 and 70 working in London when cognitive testing began in 1997 to 1999. Cognitive function was measured three times over 10 years to assess memory, vocabulary, hearing and visual comprehension skills. Tasks included recalling in writing as many words beginning with the letter S as possible and as many animal names as could be thought of.
All cognitive scores, except vocabulary, declined among all age groups during the study, and there was evidence of faster decline among older people. In men, there was a 3.6 per cent drop in reasoning after 10 years among those who were aged 45 to 49 at the start of the study and 9.6 per cent among those aged 65 to 70. In women, the decline was 3.6 per cent and 7.4 per cent in the same age groups, says a report published online in the British Medical Journal.
Dr Archana Singh-Manoux, who led the study, said there had been debate over when mental skills started failing, with some researchers concluding there was little evidence of problems before 60. But this was disproved by the study findings, she added. She said, “Cognitive decline is already evident in middle age, between 45-49 years. The results for all tests, except vocabulary, showed significant declines in all age categories in both men and women.”
The study says diseases such as dementia are believed to take at least 20 to 30 years to develop but promoting healthy lifestyles and good heart health could help. “There is emerging consensus that 'what is good for our hearts is also good for our heads', making aggressive control of behavioral and cardiovascular risk factors as early as possible key targets for clinical practice and public health” it said.
Previous research suggests around half of people with diagnosed mild cognitive impairment (MCI) develop Alzheimer’s. In cases of MCI, a person has cognitive or memory problems which are more marked than typical age-related memory loss, but not yet as severe as those found in Alzheimer’s disease.
Dr Simon Ridley, head of research at Alzheimer’s Research UK charity, said, “Experts believe that Alzheimer’s disease, the most common cause of dementia, begins to develop in mid-life. Although this study didn’t look at dementia, it would be important to follow up these participants to see which people go on to develop the condition, and it would be helpful to see similar studies carried out in a wider sample. Previous research suggests that our health in mid-life affects our risk of dementia as we age, and these findings give us all an extra reason to stick to our New Year’s resolutions. Although we don’t yet have a sure-fire way to prevent dementia, we do know that simple lifestyle changes – such as eating a healthy diet, not smoking, and keeping blood pressure and cholesterol in check – can all reduce the risk of dementia. With 820,000 people in the UK affected by dementia, it’s vital that we invest in research to find new ways to prevent and treat this devastating condition.”
Dr Anne Corbett, research manager of the Alzheimer’s Society, added, “This large, important study adds vital information to the debate over when cognitive decline begins. However, the study does not tell us whether any of these people went on to develop dementia, nor how feasible it would be for GPs to detect these early changes. More research is now needed to help us fully understand how measurable changes in the brain can help us improve diagnosis of dementia. An early diagnosis is essential as it can provide access to support and potential treatments which can vastly improve people’s quality of life.”
Professor Lindsey Davies, president of the Faculty of Public Health, said that people should not wait until their bodies and minds broke down before taking action. “This study provides extra encouragement to young and middle aged people to take care of their health – and not just for a few weeks in January. The risks to mental health and wellbeing can persuade people that it is unwise to only take action if and when their bodies and minds break down. There will be no single pill to help us do this: it's about the common sense approach of keeping fit and watching what we eat and drink,” she said. “Further research in this area would help public health experts be even more effective in taking preventative action to protect and improve older people's health. We need only look at the problems that childhood obesity rates will cause if they are not addressed to see how important it is that we take 'cradle to grave' approach to public health,” Davies said.
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