Researchers in the US have found that staying mentally active during midlife may only impact on biological markers of Alzheimer’s in particular groups of people carrying a risk gene for the disease. The research was published in the journal Neurology on 24 February 2016.
The research team from the Mayo Clinic studied a total of 393 people with an average age of 78. Of those studied, 340 people had no memory problems, while 53 people had mild cognitive impairment – mild memory and thinking difficulties not severe enough to be diagnosed as dementia. The study reports that 109 volunteers carried the APOE4 gene, which can increase the risk of Alzheimer’s more than threefold. The researchers collected information on mental activity, including years of formal education, former occupation and a questionnaire about cognitive activity during midlife (50-65 years of age). They also investigated physical activity and asked volunteers about exercise during midlife.
As well as information about lifestyle, the researchers investigated biological changes in the brain. Using sophisticated brain scans, the scientists looked for evidence of amyloid (an Alzheimer’s hallmark protein) as well as other features such as nerve cell activity and brain shrinkage. The scans were performed at two different points, to look at changes over time.
The team found that amyloid built up faster in people with the APOE4 gene. Looking across all volunteers, mental and physical activity had no impact on amyloid levels. However, when the research team looked solely at people with the APOE4 risk gene, those who were more highly educated had less amyloid in the brain than those with fewer years of formal education. Highly educated people who stayed cognitively active in midlife had less amyloid than highly educated people who did not remain as mentally active. Physical activity in midlife had no impact on amyloid levels in people with the APOE4 gene.
Dr Simon Ridley, Director of Research at Alzheimer’s Research UK, said:
“Increasing evidence suggests that staying mentally active as we age can play a role in reducing dementia risk. In this small study, higher education levels and taking part in mentally challenging activities during midlife only had an impact on hallmark features of Alzheimer’s in a subset of people with a risk gene for the disease. As none of the volunteers in the study had symptoms of dementia, it is difficult to make conclusions about the long-term impact of these factors on dementia risk. We know that amyloid, a toxic protein in Alzheimer’s, can build-up in the brain but not cause someone to experience symptoms and it is very important to explore why some people are more susceptible to the impact of the toxic protein than others.
“With the number of people in the UK living with dementia set to rise to 1 million by 2020, it’s important that we understand the steps we can take to reduce our risk of the condition as we age. Best current evidence suggest that maintaining a healthy weight, staying physically active, keeping blood pressure and cholesterol in check, eating a healthy diet and not smoking, could all help reduce dementia risk.”