Sabina Brennan directs a dementia research programme at Trinity College Dublin (TCD), so she knows a lot about how the brain functions and how to keep it in working order. She has five tips for hanging on to our brain power as we age.

1 GET PHYSICALLY ACTIVE: “Your brain is the biggest consumer of nutrients and oxygen, so regular physical exercise is needed to maintain brain health,” she says.

2 STAY SOCIALLY ENGAGED: “It is hugely important to stay socially connected as there is a direct correlation between the density of your social network and the density of the neural network in your brain.

“If you are talking to people and having stimulating conversations, you are keeping your brain engaged. We have a problem in western society – not just in Ireland – in that we have very little inter-generational contact,” she says. “We spend most of our lives with people of our own age. However, in Italy, for example, you’d see three or four generations on holiday together.”

This sticking with our own cohort causes problems in later life, she believes.

“The problem is that, as you age, you have these ever decreasing social circles and – there is no nice way to put this – they start to die off. That then compounds your isolation. You’re not as socially engaged, so your cognitive function can decline. It is really important from a lot of angles that within communities we try and set things up so that the generations find ways to mix. All generations benefit from this interaction.”

3 CHALLENGE YOUR BRAIN: “Doing the crossword or Sudoku every day may not be enough because your brain can get used to doing these things. You need to rev-up your brain by regularly presenting it with a new challenge. The new hobby itself is not important and doesn’t have to be rocket science, just something that motivates you or that you love doing. The key element is that it challenges you and you’re learning something new, because these are the things that stimulate plasticity in your brain (the ability to learn more new things).”

4 MANAGE STRESS AND THINK POSITIVE: “Stress has a huge impact on your brain and your brain function. While it is impossible to avoid stress, you have to control how you manage it. Being present minded is something that helps very much with this. Never think too far forward or too far back. A lot of stress is around worrying about the past or the future, so focusing more on living in the moment can help you manage stress. Thinking young and thinking positive are also very important.”

5 MANAGE LIFESTYLE FACTORS: “What’s good for heart health is also good for brain health because it’s your heart that pumps the blood that delivers oxygen and nutrients to your brain. Limiting alcohol consumption, not smoking, eating healthily, avoiding obesity and managing high blood pressure are important for the brain too. Controlling blood sugars is also vital if you have diabetes. Type two diabetes has been associated with an increased risk of Alzheimer’s disease and dementia in several studies, including Barnes and Yaffe 2011.

“An increasing number of people in Ireland have diabetes, which itself has modifiable risk factors (obesity, blood glucose, physical activity, hypertension, smoking). I believe if people knew that having diabetes puts them more at risk of developing dementia, they would make more informed decisions about their health and risk factors for diabetes.”


Dr Brennan believes that we should all be aware of these three key messages related to brain function:

  • 1. Cognitive decline is not an inevitable part of ageing. Some changes happen, such as absentmindedness, but a major decline in brain function is not automatically part of ageing.
  • 2. Your brain is plastic and can learn as you age.
  • 3. You can build up a cognitive reserve, starting now, to make you more resilient to brain disease.

    “Neuroplasticity is one of the most exciting discoveries of the last 30 years,” she says.

    “Knowing that our brain can change, even in later life, is really reassuring. Scientists used to think that it was set like concrete but it is actually plastic, like putty – it can bend and adapt when faced with a challenge. That challenge can be a stroke or a brain injury in a car crash or ageing or a neurodegenerative disease (like Alzheimer’s disease).

    “Neuroplasticity also allows us to cope with increasing task difficulty. If someone gets a new computer game, for instance, they can’t complete level one at first, but if they keep trying, the plasticity in their brain allows them to learn how to do it and then they progress to the next level. Not all areas of the brain are plastic but some areas involved in memory formation are, so that’s positive.”


    “You can build up this reserve or cognitive capacity across your life span so that in later life – the rainy day where you may get brain disease – you can draw on these reserves. It’s like a pension fund.

    “This allows you to preserve levels of cognitive functioning that might otherwise not be possible. You have to build up those reserves as you go along. You should start building them up now, no matter what age you are.

    “We need to invest in our brain health the same way as we teach our kids to invest in their dental health by washing their teeth everyday to prevent decay and pain. The exact same principles apply. We need to work on them as early as we can.”

    The notion of cognitive reserve comes from studies that show that although we may have some degree of brain disease, we may not actually develop the functional symptoms of the disease.

    “Two people can have that pathology yet only one develops full-blown dementia symptoms. One of them has something that has allowed them to remain resilient in the face of the pathology and to maintain their cognitive functioning. We refer to that something as cognitive reserve. We know that the lifestyle factors mentioned above can influence this reserve. This is really exciting and optimistic.”

    A Hello Brain app, developed as part of an EU-funded project led by TCD, offers suggestions for daily brain buffing. It is available from It is available here.

    You can watch a two-minute film by Dr Brennan called Why Is Attention Important? on Dr Sabina Brennan leads the Freedem Films Projects as well as the Hello Brain campaign.