Keeping the brain active through your middle age may help delay the symptoms of Alzheimer’s disease in those most at risk, new research reveals.
But for most people, physical and mental activity does not affect the underlying disease changes in the brain caused by a build up of plaques.
However a fifth of the population who are carriers of a gene linked to Alzheimer’s, called APOE4 can affect the progression of the disease through lifelong learning.
Those with the gene who stay in school and continue to read, write, play games or use computers through their middle age had less proteins, called amyloid plaques, than those with a similar education who do not.
Among the APOE4 high education individuals, the predicted amyloid levels in a 79-year-old who kept mentally active would be the same as the predicted amyloid levels in a 74 year-old who did not.
Dr Prashanthi Vemuri of the Mayo Clinic in Rochester, Minnesota, said: “Recent studies have shown conflicting results about the value of physical and mental activity related to the risk of developing Alzheimer’s disease, and we noticed that levels of education differed in those studies.
“When we looked specifically at the level of lifetime learning, we found that carriers of the APOE4 gene who had higher education and continued to learn through middle age had fewer amyloid deposition on imaging when compared to those who did not continue with intellectual activity in middle age.”
She added the overall findings for people who do not carry the gene should not discourage people from exercising and taking part in mental activities.
She said: “There is substantial evidence that these activities help to delay the onset of memory and thinking problems.
“What we don’t know is how this process works.”
The study published in Neurology, the medical journal of the American Academy of Neurology, evaluated 393 people without dementia who were part of the Mayo Clinic Study of Ageing.
Of those, 53 had mild cognitive impairment.
All were over 70 and divided into two groups, those with more than 14 years of education and those with less.
Brain scans then looked for biomarkers of Alzheimer’s disease and questionnaires to evaluate weekly intellectual and physical activity in middle age.
For the group as a whole, education, occupation and mental and physical activity in middle age appeared to have little to no effect on the rates of worsening amyloid plaques, brain glucose metabolism and brain volume.
But for APOE4 carriers with high education and continued lifetime learning, there was less amyloid deposition in the brain than those with high education who did not continue to learn.
Dr Vemuri said: “It is possible those who did not continue intellectual activity in middle age did so because they had higher levels of amyloid plaques.
“While there are many limitations with this study, our findings show further study is needed and suggest that differing education levels in other recent studies may explain the conflicting results seen in the research literature.”
The UK’s Alzheimer’s Society said the findings supports previous studies that suggested more education and keeping the mind active in mid-life can help to reduce the risk of dementia for some people.
While the underlying reasons remains unclear, the study indicates genetics could play a part.
Director of Research and Development Dr Doug Brown said: “Alzheimer’s disease is caused by a complex mix of genetics and lifestyle, and it could be that particular groups of people may benefit from making certain lifestyle changes to reduce their risk.
“This research supports this suggestion by showing that people with the APOE4 gene – which increases the chances of developing Alzheimer’s disease – seem to have better brain health if they keep their minds active throughout their lives.
“Although people with the APOE4 gene have a higher risk of dementia, there are things they, and indeed all of us, can do to cut that down.
“This might include staying fit and active, not smoking, and keeping the brain busy – this could be through reading or playing games and puzzles.”
By Tony Whitfield