We all know the drill: get moving, stay active, and you’ll keep your mind and body in good shape as you age. For years, health experts have told us that 150 minutes of exercise a week is the golden ticket to staving off a host of chronic illnesses, including dementia.
But what if we told you that even if you’re hitting your exercise targets, there’s another, much sneakier habit that could be quietly increasing your risk of Alzheimer’s disease?
A new study from Vanderbilt University Medical Center in Nashville has thrown a spanner in the works for those who thought a brisk daily walk or a few gym sessions were enough to keep our brains healthy. The culprit? Sitting—or lying down—for long stretches of the day.
We’ve all heard the phrase ‘sitting is the new smoking’ when it comes to heart health, but it turns out our brains might be just as vulnerable.
The Vanderbilt study, published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, tracked over 400 adults over 50 who were free from dementia.
Participants wore activity monitors for a week, giving researchers a clear picture of how much time they spent moving versus being sedentary.
The results were eye-opening. Even among those who met or exceeded the recommended 150 minutes of exercise per week, those who spent more time sitting or lying down had worse scores on cognitive tests and showed more brain shrinkage in areas linked to memory and learning, classic hallmarks of Alzheimer’s disease.
The risk was even higher for people carrying a particular gene variant called APOE-e4, which is known to increase the risk of Alzheimer’s by up to ten times.
About one in 50 people, including some well-known faces like actor Chris Hemsworth, carry this gene.
Professor Angela Jefferson, fellow author and expert in neurology, explained: ‘This research highlights the importance of reducing sitting time, particularly among ageing adults at increased genetic risk for Alzheimer’s disease.’
While the study can’t say why sitting is so harmful, the researchers have a theory.
Long periods of inactivity may reduce healthy blood flow to the brain, which over time could lead to structural changes and make the brain more vulnerable to the toxic protein buildups that cause Alzheimer’s.
Here in Australia, dementia is the second leading cause of death, and Alzheimer’s disease is the most common form.
Alzheimer’s is believed to result from a buildup of proteins in the brain that create clumps, making it challenging for the brain to function optimally.
As the brain grapples with this issue, symptoms of dementia can emerge. Early signs often include memory challenges, difficulties with thinking and reasoning, and language issues, which may become more pronounced over time.
Lead author Dr Marissa Gogniat sums it up: ‘Reducing your risk for Alzheimer’s disease is not just about working out once a day. Minimising the time spent sitting, even if you do exercise daily, reduces the likelihood of developing Alzheimer’s disease.’
Her colleague, Jefferson, added: ‘It is critical to our brain health to take breaks from sitting throughout the day and move around to increase our active time.’
Have you found ways to break up your sitting time, or do you struggle to stay active throughout the day? Have you noticed any changes in your memory or thinking as you age? We’d love your tips, experiences, and questions in the comments below.
Also read: Dementia risk depends on more than lifestyle factors. Overstating this can cause stigma and blame
