If you adopt a healthy diet and lifestyle, your risk of dementia is reduced compared to those couch potatoes, junk food addicts, smokers, and heavy drinkers. This is known to be accurate, but why is it true? By what mechanism is the brain safeguarded? It’s something called cognitive reserve.
Researchers turned to a long-running study that continued throughout the participants’ lives to discover why cognitive reserve matters and how to build up yours.
The research team, which includes scientists at Rush University Medical Center in Chicago, is one of the most highly regarded in the nation for brain health.
Lowering Dementia Risk Through Lifestyle
One of the Rush team’s primary research avenues is lowering the risk of dementia through diet and lifestyle strategies. They were behind the MIND diet, which substantially slows cognitive decline with age, and they’re part of the Protect Brain Health Through Lifestyle Intervention to Reduce Risk (POINTER) trial, which is currently in progress.
The hope is that this trial will confirm and expand the exciting findings of the FINGER study, which stands for the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability. The first randomized controlled trial (RCT) shows that preventing cognitive decline is possible using a multi-domain lifestyle intervention among older at-risk individuals. The results from this trial highlighted the value of addressing multiple dementia risk factors as a strategy to protect brain health, promote overall health and functioning, and reduce the risk of developing new chronic diseases.
Now, back to the Rush team and the latest findings…
Good Choices = Fewer Plaques + Better Cognition
Their new study, published in JAMA Neurology in February, included 586 men and women who participated in the Rush Memory and Aging Project between 1997 and 2022. Each year, they completed a questionnaire on their lifestyles, had regular physical checks, and took nineteen standardized cognitive tests until their death.
The Rush team gave each participant a lifestyle score and placed them in the top category if they:
- Ate a healthy diet based on the Mediterranean-DASH or MIND diet.
- Exercised for at least 2½ hours a week.
- Refrained from smoking.
- Had one or fewer alcoholic drinks (female) per day or two drinks (male).
- Stimulated the brain with games, puzzles, reading, museum visits, etc.
Each participant donated their brain to medical research and was aged 91 on average upon death. Autopsy analysis included searching for both hallmarks of Alzheimer’s disease– beta-amyloid plaque load and tau tangles - as well as analyzing cerebrovascular pathology (the blood vessel structure and function) and other brain pathologies that have been linked to Alzheimer’s disease.
Their findings showed that each one-point higher lifestyle score was associated with a 0.12-unit lower beta-amyloid load in the brain and a 0.216-unit higher score in overall cognitive performance.
But here’s the most important part: All that talk from doctors and scientists over the years about the importance of beta-amyloid plaque and tau tangles? The study shows those don’t hold a candle to the power of your lifestyle choices.
Brain Pathologies are Irrelevant
The researchers weren’t surprised to discover that their study demonstrated that a healthier lifestyle was linked to better cognitive function before death. What was of greater interest was this: “The lifestyle-cognition association was independent of Alzheimer disease pathology burden; that is, neither the strength nor the significance of the lifestyle-cognition association changed substantially when beta-amyloid load, phosphorylated tau tangle, or other dementia-related brain pathologies were included.”
In other words, lifestyle improves people’s memories regardless of the amount of plaque or tangles in their brains. Since brain pathologies proved largely irrelevant, and no mechanism was uncovered to explain the findings, the Rush team concluded that “lifestyle factors may provide cognitive reserve in maintaining cognitive abilities in older adults.”
Cognitive reserve refers to the brain’s ability to build resilience to adapt and cope with challenges such as the growth of plaques, tangles, or vascular changes with aging.
Trying to come up with some kind of mechanistic explanation the research team suggested their findings might be partly attributable to the antioxidant and anti-inflammatory capacities of each lifestyle factor.
Plaques and Tangles: Effects, Not Causes
The study doesn’t get us any closer to discovering the cause of cognitive decline and dementia, but it does show that scientists need to look beyond brain plaques and changes in blood flow as an explanation.
This lesson should have been learned eight years ago.
Back in 2016, Northwestern Medicine researchers, also based in Chicago, studied the brains of people over 90 who had sharp memories until they died. Autopsies revealed widespread and dense Alzheimer’s plaques and tangles in some of the nonagenarians that would be considered full-blown Alzheimer’s pathology.
Lead investigator Changiz Geula said, “This is amazing. We never expected it. It tells us there are some factors that are protecting their brains and memories against the Alzheimer’s pathology of plaques and tangles. Now we have to find out what those are.”
We couldn’t agree more.
Our Takeaway
We’ve long reported on research that reveals autopsy results confirming that some people die with memories intact and brains chock full of plaque and tangles. While the mystery still isn’t solved, the conclusion of the latest research is undoubtedly a good one: Your diet and lifestyle are the most important components of building cognitive reserve and maintaining a sharp, clear memory as you age.
So, look at the list from above—the five ways the participants in the Rush study maintained cognitive reserve throughout their lives. See how your lifestyle stacks up. Also, two more lifestyle choices are clinically proven to build cognitive reserve…
- Manage your stress level with regular stress relief techniques such as spiritual practices, meditation, exercise, or therapy.
- Get enough sleep. It’s easier to achieve a good night’s sleep when you go to bed and wake up around the same time each day.
Adopting a brain-saving, cognitive-reserve-building lifestyle is easier than you think. Give it a try this week.
