Mind your brain health: How to protect your cognitive abilities

“The reason the number of people with dementia is rising is because we’re living longer, and the likelihood of dementia gets higher with age,” he says.

What the statistics don’t tell us is that our dementia risk is falling. “Data from dementia registries worldwide reveal that the risk of an 80-year-old developing dementia now is 40% lower than it was 40 years ago,” says Kennelly.

 “Overall dementia rates may be rising because the global population is living longer, but our individual dementia risk is lower than it’s ever been thanks to better diets, better control of high blood pressure and cholesterol levels and better treatment of diabetes.”

Let’s clarify what dementia is before we dig deeper. Brian Lawlor, a professor of old age psychiatry and site director of the Global Brain Health Institute at Trinity College Dublin, explains that it’s an umbrella term for various brain diseases.

“These diseases impair a person’s ability to think, plan and organise,” he says. “They affect memory, language and behaviour and interfere with day-to-day function. Alzheimer’s disease is one of the most common.”

These diseases have a genetic component. Some, like familial frontotemporal dementia, are highly genetic,” says Lawlor. “But for most, the genetic contribution isn’t definitive. Having the gene doesn’t mean you will develop dementia. It just makes you more susceptible.”

Dr Jonathan Rosand, a neurologist at the Massachusetts General Hospital McCance Centre for Brain Health in the US, elaborates further on the role genes play in dementia and other conditions that affect the brain, like stroke and depression.

“Genes aren’t destiny,” he says. “Lifestyle is important too. It’s estimated that as much as 40% of dementia cases, 60% of stroke cases and at least 35% of depression cases could be prevented by the choices we make daily. To some extent, the health of our brains is in our own hands.”

The FINGER study, published in 2015, was one of the first to prove this. Carried out in Finland, it followed 1,260 people aged between 60 and 77 identified as being at possible risk of dementia.

Half were enrolled in a two-year programme that involved interventions in diet, physical activity, cognitive training, social activity, and monitoring of cardiovascular risk problems. The other half received regular health advice.

There was a significant difference in outcome at the end of the two years, with the second group demonstrating a 30% higher risk of developing cognitive impairment.

A Lancet Commission report issued in July of this year further reinforced the influence of lifestyle factors. It concluded that 45% of dementia cases could be delayed or have their symptoms reduced if specific lifestyle factors were addressed.

One of these relates to our early years education. “The longer we remain in education, the more we build up a cognitive reserve and the less likely we are to develop dementia,” says Kennelly. 

“The fact that some 90% of people in Ireland now complete secondary school should have a massive dividend in terms of cognitive health in years to come.”

Middle-age effects

Dr Seán O’Dowd is a consultant neurologist at Tallaght University Hospital and the clinical lead of Ireland’s National Dementia Services. 

He points out that several factors that kick in during middle age relate to heart health.

“What affects the heart affects the brain,” he says. “The factors associated with cardiovascular risk are also associated with dementia, so if we mind our hearts, we reduce our dementia risk, and as an added bonus, we reduce our stroke risk too.”

Quitting smoking is critical to improving heart health, as is monitoring and treating high blood pressure and cholesterol.

“Managing diabetes, maintaining a healthy weight and avoiding excessive alcohol consumption are also important,” says O’Dowd. 

“We should start addressing these modifiable risk factors in mid-life, particularly from 45 onwards.”

Other factors that come into play in middle age are depression, traumatic brain injury and hearing loss.

“Hearing loss surprises people but is consistently associated with dementia,” says O’Dowd. “Perhaps it’s because not being able to hear well means you’re less inclined to engage in group activities or conversations and have less cognitive stimulation as a result. Whatever the case, hearing aids can mitigate the risk.”

One of the best ways to improve brain health is to engage in more physical exercise. Kennelly’s Institute of Memory and Cognition at Tallaght Hospital runs a brain health clinic to help people experiencing minor memory issues prevent further cognitive decline. 

Graham Knight, an advanced nurse practitioner in the clinic, recommends 150 minutes of intense exercise weekly to his patients.

“This gets the heart rate up and increases blood flow, delivering more oxygen and nutrients to the brain,” he says. 

“You can achieve this by walking fast, running or doing other aerobic exercises, but you’ll know you’re doing it right when you’re breathing harder than you normally do.”

The Lancet Commission identified social isolation as a detrimental factor among older people. An international study involving researchers from the University of Limerick published this October showed just how damaging isolation can be. 

"Using data from 608,561 people around the world, it found that feeling lonely increased the risk of dementia by 31%.

This doesn’t surprise Kennelly. “Socialising is how we take our brain to the gym,” he says. “In conversations with others, we’re drawing on wells of information based on our previous interactions with them. 

"We’re moving from one topic to another and trying to keep several things in mind at once. It’s a cognitive workout.”

In his clinic, Kennelly adds other lifestyle factors to the list outlined by the Lancet Commission.

Diet is one. “The Mediterranean diet, in particular, with its emphasis on fruit and vegetables, whole grains, olive oil, beans and fish, has been associated with slowing cognitive decline and lower risk of Alzheimer’s,” he says.

Sleep quality is another. “Sleep disturbances and disorders can definitely have a role to play in memory problems,” says Kennelly.

Finally, there is stress. Kennelly outlines how our stress response evolved to focus all our thoughts and actions on evading immediate threats.

“That worked fine when the threat was a tiger,” he says. “But many of us now deal with chronic stress, and that single-minded focus on one thing can affect our memory function by making it harder to make and store memories. 

"Stress is also associated with chronic inflammation, which is associated with the accumulation of proteins that are a risk factor for Alzheimer’s.”

At the brain health centre where he works, Rosand has incorporated all these lifestyle factors into a questionnaire he calls the Brain Care Score, which he uses to predict people’s risk of developing dementia, stroke and depression.

“It’s a score to make prevention simple by highlighting what we can do to protect our brains daily and to blunt the effects of any genetic susceptibility we may have been born with,” he says.

Because the body is an interconnected system, he reminds us that improving brain health will improve overall health. “Your risk of heart disease and lung, breast, and colorectal cancer will reduce, too,” he says.

The team in Tallaght’s brain health clinic follow a similar approach to Rosand, measuring each person’s risk factors to determine a risk score.

“We identify how they can address those risks and devise a personalised prevention plan to help them do so,” says Knight. “This leads to cognitive improvements for some and prevents further decline in others.”

Prevention is best

There is a growing understanding of the need to take a preventative approach to brain health throughout the health service. 

The HSE has a brain health working group, and they are currently carrying out a large-scale survey to establish what the population knows about brain health and how it can be optimised.

“The findings will form the foundation of future public health campaigns and programmes for brain health interventions,” says O’Dowd.

Lawlor believes that brain health is where heart health was two or three decades ago. “When I was younger, people dropped dead of heart attacks right, left and centre,” he says. 

“This doesn’t happen anymore because we know what we can do to prevent it. We need to do the same with brain health. Our brains are our most important assets. We shouldn’t wait until we are older and at increased risk of cognitive decline or dementia before we start looking after them. People need to be told what they can do to keep their brains sharp long before that.”

With this in mind, the Global Health Institute launched My Brain Robbie in 2019. These animated videos help children between the ages of six and 12 learn how to keep their brains healthy.

“They show that it’s never too early to start looking after your brain,” says Lawlor.

Nor is it ever too late, adds O’Dowd. “Improving our physical, cognitive and social activity levels will help to protect our brain at any age,” he says. “It will benefit our overall health too, allowing us to maximise our chances of ageing well.”

Minimising dementia risk

The message regarding age-related dementia and cognitive decline is a hopeful one. There is a lot that we can do to minimise our risk.

Dr Jonathan Rosand, a neurologist at the Massachusetts General Hospital McCance Centre for Brain Health, has devised a brain care score that makes 12 recommendations.

• Monitor your blood pressure and take steps to lower it if it’s high.
• Control your blood sugar levels and any associated risk of diabetes.
• Keep cholesterol levels under control.
• Maintain a healthy weight.
• Eat a diet rich in fruit and vegetables, lean proteins, whole grains, and low in salt and sugar.
• Drink alcohol in moderation.
• Don’t smoke.
• Get the recommended amount of physical exercise.
• Aim for over seven hours of sleep a night and treat any sleep disorders.
• Manage your stress levels.
• Prioritise your connections with family, friends and members of your wider community.
• Try to find something that gives you purpose and meaning in life.

Prof Seán Kennelly, consultant physician in geriatric medicine and director of the Institute of Memory and Cognition at Tallaght University Hospital, adds that menopausal women should take care of their health.

“We know that women suffer from cognitive symptoms, including memory problems and brain health as they approach menopause, and we also know that Alzheimer’s affects women twice as much as it affects men,” he says. 

“We don’t know why this is, but it does show the importance of attending to women’s health.”

Also, keep up to date with flu vaccinations. “There is now a clear link that shows that getting the flu vaccine on an annual basis reduces the risk of dementia in later life,” says Kennelly. 

“It could be because by avoiding the flu, you avoid inflammation in the brain, which is a big part of developing dementia.”