February is Heart Month. Did you know that heart-healthy living can reduce your risk of dementia? But why is still debated among researchers. Is it because heart health has a direct impact on dementia or because activities that benefit the heart also improve brain health?
I spoke with Dr. Jane Rylett, a researcher at Western University and Board Member at the Alzheimer Society of Ontario.
Is exercise beneficial for brain health because it is good for your heart or are there other factors at play?
“Initially, researchers believed that the link between exercise and dementia was directly related to its benefits to the heart. Because exercise increases blood flow throughout the body, more blood reaches the brain along with key nutrients, oxygen etc.
But now research is showing that other factors are involved:
- Animal models as well as human studies have shown that exercise increases brain stem cell growth and neuroplasticity (the ability of the brain to change neural pathways and synapses).
- The body’s metabolic rate increases during exercise, which helps regenerate the brain.
- Exercise has also been shown to benefit the brain’s nerves cells.
- Diabetes, which is linked to poor diet and lack of exercise, also seems to increase the risk of Alzheimer’s.
So the benefits of exercise appear to go beyond just having a healthy heart, although the two are certainly linked.”
Why does a heart-healthy diet, low in saturated fats and cholesterol, help protect against dementia?
“This is one of the most direct ways heart health impacts the brain. If a person has poor cardiovascular health, which can be the result of a poor diet and lack of exercise, blood flow to the brain decreases. The brain receives less oxygen and other key nutrients as a result.
This can also lead to mini-strokes in the brain. Mini-strokes are so small you may not even know you’ve had one. But over times, these can be detrimental to your brain health and is a cause of vascular dementia. ”
What’s the link between smoking, heart health and dementia?
“The link with smoking, which definitely harms vascular health, is less clear. It has been hard to prove that smoking leads to dementia. However, since it can compromise heart function and general health, the relationship may be linked in that aspect.”