Walk 10,000 steps a day, cut down on alcohol, get a better night’s sleep, stay socially active — we’re told changes like these can prevent up to 40 percent of dementia cases worldwide.
Since dementia is still one of the most feared diseases, why aren’t we pushing our doctors and governments to support these lifestyle changes through new programs and policy initiatives?
The truth, however, is more complex. We know that changing lifestyles is difficult. Ask anyone who has tried to keep their New Year’s resolution to hit the gym three times a week. It can be doubly difficult when the changes we need to make now won’t show results for years or even decades, and we don’t really understand why they work.
Taking control of your health
Anyone who has watched a loved one live with dementia, dealing with the small and large indignities and decline that eventually leaves them unable to eat, communicate or remember, knows that it is a devastating disease.
There are several new drugs coming to the market for Alzheimer’s disease (one of the most common forms of dementia). However, they are still a long way from a cure and are currently only effective for early-stage Alzheimer’s patients.
So lifestyle changes may be our best hope for delaying dementia or not developing dementia at all. Actor Chris Hemsworth knows this. He watched his grandfather live with Alzheimer’s and make lifestyle changes after learning he has two copies of the APOE4 gene. This gene is a risk factor for Alzheimer’s disease, and having two copies greatly increases the risk of developing the same condition.
Research has identified modifiable risk factors that contribute to an increased risk of dementia:
- physical inactivity
- excessive use of alcohol
- less sleep
- Social isolation
- hearing loss
- less cognitive involvement
- bad nutrition
- traumatic brain injury
- air pollution
Our understanding of the biological mechanisms for these risk factors is varied, with some being better understood than others.
But there’s a lot we do know—and here’s what you need to know, too.
Cognitive reserve and neuroplasticity
Cognitive reserve is the brain’s ability to withstand damage or neurodegenerative disease. If there is tissue loss or functional loss in one part of the brain, other brain cells (neurons) work harder to compensate. In theory, this means that a lifetime of experiences and activities create a barrier against the damage of disease and aging in the brain.
Neuroplasticity is the brain’s amazing ability to adapt, learn and reorganize, creating new pathways or rewiring existing ones to recover from damage. The key point is that neuroplasticity can happen at any time and at any age, which means that learning and activities must be lifelong.
Many of the risk factors associated with dementia likely work in combination, so a holistic lifestyle approach is vital. For example, studies have shown that exercise, cognitive and social engagement stimulate your brain and maintain its plasticity by developing new neural connections and building cognitive reserve.
The mechanism behind this is a combination of factors: increased oxygen and blood flow to the brain, stimulation of growth factors that keep neurons healthy, and reduced inflammation.
The opposite is also true. Poor sleep, dieting, social isolation, and untreated depression are associated with reduced cognitive reserve.
The same reasoning applies to hearing loss, a key emerging risk factor for dementia. As a person’s hearing declines, it can make it difficult to socialize with others, resulting in a loss of sensory input. The brain has to work harder to compensate for this, possibly reducing its cognitive reserve and leaving it less able to cope with dementia.
The role of stress and inflammation
Stress responses and inflammation are the body’s complex response to injury. Inflammation is an important component of the body’s immune system, helping to defend against threats and repair tissue damage. While short-term inflammation is a natural and good response, chronic or prolonged inflammation disrupts normal function and causes damage to brain cells.
For example, one of the commonalities between dementia and depression that is not addressed is the inflammatory process. Prolonged exposure to stress hormones can lead to chronic inflammation. High blood pressure, physical inactivity, smoking and air pollution are also linked to chronic inflammation and stress, which can damage blood vessels and neurons in the brain.
In a newer area of research that is still being explored, social isolation has also been linked to inflammation. As we learned during the COVID-19 pandemic, the brain is wired to respond to social engagement as a means of connection and emotional support, especially in times of distress.
With research showing that more than one in three Canadians feel isolated, lack of social connection and loneliness can trigger the body’s stress response and neuroendocrine changes, and prolonged exposure to this inflammatory process can damage the brain.
Similar pathways in many diseases
Several of these risk factors and their biological pathways influence many chronic diseases. The accumulated evidence of decades of research supports the concept of “what’s good for your heart is good for your head.”
This means that making these lifestyle changes not only reduces your risk of dementia, but also your risk of diabetes, high blood pressure and heart problems. This highlights the complex nature of dementia, but also offers a single strategy to address the multiple health problems that can arise as people age.
It’s never too late
It’s never too late to change. The human brain and body have a remarkable capacity for adaptation and resilience throughout life.
Although there are benefits to being physically and socially active at any age, some research suggests that the reward for these gains may be greatest after age 40, when the body’s metabolism slows, risk factors increase, and cognitive reserve becomes even more necessary to protect against cognitive decline.
If making lifestyle changes means you can watch your child grow into adulthood, walk 20 blocks to your favorite coffee shop every day, and still live in your home, it might be worth it to walk 10,000 steps a day, change diet and keep your friendship network strong. At worst, you’ll be healthier and more independent with or without dementia. At best, you may avoid dementia and other major illnesses altogether and go on to live your best life possible.
This article is republished from The Conversation under a Creative Commons license. Read the original article.