#048 - Dementia Defence
Most Dementia Risk Is Modifiable
For many people, dementia feels inevitable.
If it runs in the family, the assumption is often that it’s simply a matter of time.
However, the science is becoming increasingly clear that a large proportion of dementia risk is actually modifiable.
Major global studies now estimate that between 45% and 70% of dementia cases could potentially be prevented through lifestyle factors.
That doesn’t mean prevention is guaranteed. Genetics still plays a role.
But it does mean that the way we live, how we move, eat, sleep, and challenge our brain has a significant influence on how our brain ages.
Think of it less like flipping a switch and more like stacking the odds in your favour over decades, like chipping away at a pension.
Here are some of the biggest levers we currently know about.
Movement Is One of the Best Brain Protectors
Exercise doesn’t just strengthen the body, it directly supports brain health.
When we exercise, the body releases a range of molecules that help support brain structure and function. One of the most important is BDNF (Brain Derived Neurotrophic Factor), often described as fertiliser for the brain.
BDNF supports the growth of new neurons and strengthens the connections between them, which is essential for learning and memory.
Research shows that aerobic exercise is particularly powerful for this. In fact, some studies have shown improvements in the hippocampus (the brain region most closely associated with memory) after structured aerobic training.
High-intensity interval training appears to be especially effective. One well-studied method is the 4x4 interval protocol, which involves four minutes of hard effort followed by recovery, repeated four times.
But intensity is only one part of the picture.
Activities that challenge coordination and reaction speed can be particularly beneficial for the brain.
Examples include:
Dancing
Tennis or racket sports
Martial arts
Team sports
Skiing or board sports
These are sometimes referred to as open skill activities, meaning the environment is constantly changing and the brain has to adapt in real time.
The brain thrives on movement that requires thinking.
The Brain Needs Challenge to Stay Healthy
Just like muscles, the brain adapts when it is pushed.
Activities that require learning, problem solving, and occasionally getting things wrong stimulate neuroplasticity, the brain’s ability to form new connections and reorganise itself.
Over time, this builds something called cognitive reserve.
Cognitive reserve refers to the brain’s ability to maintain function even when age-related changes occur. People with greater cognitive reserve often maintain their thinking and memory for longer, even if some structural changes in the brain have begun.
Some of the most powerful activities for building cognitive reserve include:
Learning a new language
Playing a musical instrument
Dancing or complex movement training
Strategy games or puzzles
Interestingly, bilingual individuals tend to perform better on tasks involving attention and response control, and some studies suggest they experience delayed onset of dementia symptoms.
The key isn’t simply staying busy, the key is continuing to learn things that are genuinely challenging.
The brain grows through effort.
Brain Health and Physical Health Are Closely Linked
Many of the biggest risk factors for dementia are the same ones that drive cardiovascular disease.
These include:
Smoking
High blood pressure
Obesity
Physical inactivity
In other words, protecting the brain often means protecting the body as a whole.
Sleep also plays a critical role.
During deep sleep, the brain performs a type of housekeeping process, clearing waste products that accumulate during the day. This includes proteins associated with Alzheimer’s disease.
Consistently poor sleep may interfere with this process and increase long-term cognitive risk.
Improving sleep quality doesn’t necessarily require drastic measures.
Some simple strategies include:
Maintaining a consistent sleep schedule
Reducing bright screens and artificial light in the evening
Keeping the bedroom cool and dark
Allowing time to wind down before bed
Good sleep isn’t simply about feeling rested. It’s an essential part of long-term brain maintenance.
Nutrition Plays an Important Role
The brain is an energy-hungry organ and requires a steady supply of nutrients to function well.
One group of nutrients that appears particularly important are omega-3 fatty acids, especially DHA.
DHA is incorporated directly into brain cell membranes and plays a role in communication between neurons, inflammation control, and overall brain structure.
A practical target is:
Two to three servings of oily fish per week, or
Around 1–2 grams of omega-3 supplementation daily
Other nutrients that appear supportive for brain health include:
B vitamins such as B12 and folate
Vitamin D
Magnesium
Polyphenols from foods like berries, tea, coffee, and nuts
Overall, the dietary pattern with the strongest evidence for long-term brain health is the Mediterranean-style diet. Rich in vegetables, healthy fats, fish, whole foods, and minimal ultra-processed food.
This style of eating supports both cardiovascular health and brain function.
Don’t Ignore Hearing and Vision
One of the most overlooked risk factors for dementia is hearing loss.
Reduced hearing doesn’t just affect communication. It also reduces sensory stimulation to the brain and can lead to reduced social interaction.
Over time, this combination may accelerate cognitive decline.
Encouragingly, research suggests that using hearing aids can significantly reduce this risk, particularly in people already at higher risk of dementia.
Vision also plays a role. Cataract surgery, for example, has been associated with a lower risk of cognitive decline.
Sometimes protecting the brain simply means making sure it continues to receive clear information from the world.
Small Habits Provide Big Returns
One of the most interesting findings from recent research is that even moderate levels of daily movement can make a difference.
Walking around 4,000 steps per day has been associated with roughly a 25% reduction in dementia risk, with benefits continuing to increase up to around 10,000 steps per day.
This reinforces an important point. You don’t need extreme interventions or complicated routines. Consistency matters far more than perfection.
The Bottom Line
Brain health isn’t determined by a single habit.
It’s the result of many small behaviours interacting over decades.
Movement, nutrition, sleep, cognitive challenge, social engagement, and overall health all contribute.
When these habits stack together, they can significantly shift the odds in your favour.
Ageing is inevitable, but cognitive decline is far more modifiable than most people realise
The earlier these habits are built, the more powerful their long-term effect can be.
James Royle
Co Founder