EXERCISE HELPS PROTECT OUR BRAIN CELLS in ways we do not fully understand. A new study indicates that physical activity plays a role in maintaining our insulin levels and body mass index, helping us fend off dementia by protecting our brain’s gray matter. Let’s look at the relationship between exercise and mental health.
Let’s look at this new research report, published in the April 2022 online issue of Neurology. First, I want to provide you with a brief overview of dementia.
Dementia by the numbers
Dementia is marked by cognitive impairment, usually affecting memory and at least one other cognitive domain (such as executive function, language, or visuospatial sense).
With dementia, there is a decline from previous levels of function, with the impairment sufficiently severe to interfere with daily function and independence.
I previously wrote about Alzheimer’s dementia, quoting the US Centers for Disease Control and Prevention: Alzheimer’s disease risk rises with age — the number of people with the condition doubles every year after 65 years old.
The number of individuals with the condition (and other dementia forms) will triple worldwide over the next few decades: The incidence will rise from an estimated 57 million in 2019 to 152 million by 2050.
Dementia — Potentially modifiable risk factors
While we do not have high-level evidence to optimize dementia risk reduction, I have some optimism that if we modify our lifestyle (particularly in mid-life), we may delay or prevent many cases of dementia.
Some good news: Large population-based research studies point to a decline in dementia incidence in high-income countries over the last several decades. For example, among subjects in the Framingham Heart Study (USA), dementia incidence has dropped in the last 30 years.
We have some hints that there are modifiable risk factors for dementia and other conditions associated with memory loss. A 2017 review of the clinical literature offers promise. The authors assert that we should “be ambitious about prevention.”
More specifically, they give us this key message: Be ambitious about prevention. The experts from The Lancet Commission recommend:
- Active treatment of high blood pressure from age 45 years to reduce dementia incidence.
- More childhood education
- Exercise
- Social engagement
- Avoiding smoking
- Managing hearing loss, depression, diabetes, and obesity
In their view, such interventions may delay or prevent one-third of dementia cases.
Dementia and exercise
Physical activity may lower the risk for dementia, but the mechanisms underlying this association are unclear. Researchers recently assessed cardiovascular risk factors and their relationship to brain integrity markers in older adults.
At study entry, participants from the Age-Well study completed a physical activity questionnaire. They also analyzed cardiovascular risk factors, with assessments of systolic blood pressure, body mass index, current smoker status, HDL (“good”) cholesterol, and insulin levels.
Each study participant also had multiple imaging forms, including two forms of MRI and two types of PET scans. The researchers then assessed the association between physical activity, cardiovascular risk factors, and brain imaging.
Let’s look at the remarkable findings:
Changes in insulin level and body mass index mediate the associations between physical activity and brain gray matter (including a structure central to memory, the hippocampus).
Older adults practicing physical activity get cardiovascular benefits by maintaining lower insulin levels and BMI, which is associated with greater structural brain integrity.
On the other hand, the association with brain glucose metabolism appears to be independent of cardiovascular risk factors.
The brain, dementia, and exercise
I write a lot about the effects of midlife cardiovascular risk factors on brain health. The current study of a relatively healthy population (without serious cardiovascular risk factors) has strong implications: We now better understand how physical activity affects brain health.
The findings may help us develop better strategies to prevent or delay brain declines. For now, I will continue to walk my way throughout each day. It is a glorious day today in the United States Pacific Northwest.
Thank you for joining me today in this look at exercise and mental health.
The information I provided in this blog is for educational purposes only and does not substitute for professional medical advice. Please consult a medical professional or healthcare provider if you seek medical advice, diagnoses, or treatment. I am not liable for risks or issues associated with using or acting upon the information in this blog.
