Walk 10,000 steps daily, reduce alcohol consumption, improve sleep, and maintain social engagement — we often hear such lifestyle alterations can prevent up to 40 percent of dementia cases globally. Considering dementia remains one of the most dreaded illnesses, why are we not urging doctors and governments to promote these lifestyle changes through new programs and policy initiatives? The reality is more intricate. We understand that altering lifestyles is challenging. Anyone who has attempted to stick to a New Year’s resolution of going to the gym three times weekly would agree. It is even harder when the necessary changes won’t manifest results for many years and we do not fully understand why they are effective.
Anyone who has witnessed a loved one suffer from dementia, experiencing the small and significant losses that ultimately prevent them from eating, communicating, or remembering, knows it to be a heart-wrenching condition. There are several new medications on the verge of being available for Alzheimer’s disease, a prevalent type of dementia. However, they are far from a cure and are presently only suitable for early-stage Alzheimer’s patients.
Lifestyle changes might be our best chance to delay dementia or avoid it altogether. Actor Chris Hemsworth is aware of this. He saw his grandfather live with Alzheimer’s and is adopting lifestyle changes after discovering he possesses two copies of the APOE4 gene, a risk factor for Alzheimer’s, which greatly increases his likelihood of developing the condition. Research has pinpointed modifiable risk factors that raise the likelihood of dementia: Our knowledge of the biological mechanisms behind these risk factors varies, with some being better understood than others. Yet, there is much known — and here’s what should be understood too.
Cognitive reserve refers to the brain’s capacity to resist harm or neurodegenerative disease. If one area of the brain suffers tissue or functional loss, other neurons work extra hard to compensate. Theoretically, this signifies that lifelong experiences and activities construct a barrier against disease and aging damages in the brain. Neuroplasticity denotes the brain’s incredible ability to adapt, learn, rearrange, create new pathways, or rewire existing ones to recover from damage. The essential takeaway is that neuroplasticity can occur at any age, meaning learning and engaging in activities should be lifelong. Many risk factors connected to dementia likely interact, which underscores the importance of an overall lifestyle strategy.
For instance, studies have demonstrated that physical, cognitive, and social engagement stimulate the brain and preserve its plasticity by generating new neural connections and enhancing cognitive reserve. The underlying mechanism involves increased oxygen and blood flow to the brain, stimulating growth factors that maintain neuron health and reducing inflammation. Conversely, poor sleep, a deficient diet, social isolation, and untreated depression correlate with reduced cognitive reserve. The same reasoning applies to hearing loss, an emerging critical risk factor for dementia. As someone’s hearing diminishes, social interactions become harder, resulting in a sensory input loss. The brain compensates by exerting more effort, potentially depleting cognitive reserve and making it less able to resist dementia. Stress responses and inflammation are the body’s intricate reactions to harm.
Inflammation forms a crucial part of the immune system, assisting in defending against threats and repairing tissue damage. While short-term inflammation is a natural and beneficial response, prolonged inflammation disrupts normal functioning and harms brain cells. For example, one shared aspect of dementia and untreated depression is the inflammatory process. Extended stress hormone exposure can lead to chronic inflammation. Hypertension, physical inactivity, smoking, and air pollution are also linked to persistent inflammation and stress, which can damage the brain’s blood vessels and neurons. A new research area still being explored connects social isolation to inflammation. As observed during the COVID-19 pandemic, the brain is designed to react to social engagement to facilitate bonding and emotional support, especially during distressing times. With over one-third of Canadians reporting feelings of isolation, the absence of social connections and loneliness can initiate the body’s stress response and neuroendocrine changes, with extended exposure to this inflammatory process potentially damaging the brain.
Several of these risk factors, along with their biological pathways, affect multiple chronic diseases. Decades of evidence back the concept “what’s beneficial for the heart is beneficial for the brain.” This implies that adopting these lifestyle changes not only lessens dementia risk but also reduces the risks of diabetes, hypertension, and heart problems. This underscores the intricate nature of dementia while also offering a unified approach to tackle multiple health issues that may emerge with aging. It is never really too late for change. The human brain and body possess an extraordinary capability for adaptation and resilience throughout life. While being physically and socially active is advantageous at any age, some research indicates that the gains from such activities can be greater after age 40, when metabolism slows, risk factors rise, and cognitive reserve becomes even more vital to guard against cognitive decline.