How Can Lifestyle Habits Help Prevent Cognitive Decline? | Neuroscientist Dr Tommy Wood

TL;DR

Cognitive decline can be slowed by supporting general health and repeatedly challenging the brain with unfamiliar, difficult tasks. Although most measured cognitive functions decline on average from the 20s or 30s onward, the brain can still form new connections and produce new cells in parts of the hippocampus. Read on to understand cognitive reserve, age-related dementia, and why decline is not a fixed trajectory.

Transcript

I think that the common view in society is that as we get older our brain function has to decline what's your view I think that it's true that it does on average and you can see that uh multiple large population studies show that pretty much every cognitive function that you can measure decreases fairly linearly over time except for memory about th... Read More

Key Insights

• Most measured cognitive functions decline fairly linearly with age across large population studies, including executive function and short-term memory. However, these averages describe populations rather than an unavoidable outcome for every individual, and the trajectory of decline can be changed substantially.
• The adult brain can continue adapting throughout life by producing new cells in some hippocampal areas and creating new connections among existing cells. Challenges can also alter surrounding brain structures, with some studies showing measurable enlargement of stimulated areas on MRI scans.
• Brain function responds to training in a way that resembles muscular adaptation. Asking the brain to perform unfamiliar or difficult tasks encourages structural and functional changes, while accepting the belief that decline is unavoidable can discourage the challenging activities needed to preserve capacity.
• Modern population studies often examine people with poor background health. The populations described are largely Westernized and industrialized, where most people have at least one metabolic syndrome component, average one prescription medication, and commonly have a chronic health condition.
• Poor systemic health is associated with worse brain health and a greater risk of cognitive decline. Because very healthy people are now difficult to find in sufficient numbers, researchers face challenges when trying to separate biological aging from the effects of widespread metabolic and chronic illness.
• Early-onset familial Alzheimer's disease accounts for less than five percent of cases and can appear from the 30s through the 50s. It is caused by a single mutation in one of several possible genes and typically produces a steady, relatively rapid decline.
• Late-onset age-related dementia is highly variable and may occur from the 60s through the 80s or later. Its expression differs according to each person's genetics, environment, lifestyle, and general health, making it distinct from the originally described familial Alzheimer's disease.
• Cognitive reserve is the capacity available beyond what everyday tasks require. Dementia becomes functionally apparent when declining capacity approaches the demands of daily life, leaving too little reserve for additional challenges and eventually making ordinary activities difficult to complete.

Questions & Answers

Q: How can you protect your brain from cognitive decline?

Support your general health and regularly ask your brain to perform unfamiliar or difficult tasks. These challenges encourage brain cells to form new connections and can change supporting structures, helping preserve cognitive capacity beyond routine daily needs.

Q: Is cognitive decline an inevitable part of aging?

Most measured cognitive functions decline on average with age, including executive function and short-term memory. Some decline is expected while aging continues, but its speed, trajectory, and eventual severity can be changed substantially.

Q: How does challenging the brain support cognitive function?

A new challenge requires brain cells and networks to adapt by forming connections and changing surrounding structures. Studies discussed here found that stimulated brain areas can become measurably larger on MRI scans, much as muscles adapt when trained.

Q: Can adults produce new brain cells as they age?

Adults can produce new brain cells in some areas of the brain, particularly parts of the hippocampus associated with memory. Existing cells can also create new connections, so the brain retains several ways to adapt later in life.

Q: When does age-related cognitive decline begin?

Average cognitive decline may begin after brain development finishes, generally in the 20s, mid-20s, or early 30s. Structural and functional changes can therefore start decades before dementia becomes detectable in everyday life.

Q: What is the difference between familial Alzheimer's disease and age-related dementia?

Familial Alzheimer's disease is caused by a mutation in one of several genes, can produce dementia from the 30s through the 50s, and represents less than five percent of cases labeled Alzheimer's. Age-related dementia generally appears later and varies according to genetics, environment, lifestyle, and general health.

Q: How does cognitive reserve relate to dementia?

Cognitive reserve is the brain's capacity beyond what routine daily activities require. Dementia becomes functionally apparent as declining capacity approaches everyday demands, leaving too little reserve for additional challenges and eventually making ordinary tasks difficult.

Q: Why is it difficult to separate aging from poor health in cognitive studies?

Many studies examine modern Westernized industrialized populations that are unhealthy on average. The vast majority have at least one metabolic syndrome component, while participants average one prescription medication and at least one chronic health condition, making the effects of aging and poor systemic health difficult to separate.

Summary & Key Takeaways

• Most measured cognitive abilities decline on average from the 20s or 30s onward, but the rate and eventual severity are modifiable. The brain retains an ability to adapt, form connections, and change its structure when challenged, so aging does not eliminate the possibility of improving or preserving cognitive function.

• Early-onset familial Alzheimer's disease is rare, strongly genetic, and caused by a mutation in one of several genes. Most cases labeled Alzheimer's occur later, vary substantially among individuals, and are influenced by genetics, environment, lifestyle, and general health. The discussion describes this more common condition as age-related dementia.

• Cognitive impairment develops along a continuum that may begin decades before dementia becomes detectable. As cognitive capacity falls, the brain gradually loses its reserve beyond routine demands. Maintaining that reserve requires unfamiliar challenges, continued learning, and opportunities to explore, attempt difficult tasks, make mistakes, and build new connections.