Here she shares questions people ask her about brain health and what we can do to look after it.
Why do we feel mentally drained after a long day – and what can we do about it?
You might think if you’re not doing physical work all day, you shouldn’t feel tired – but making decisions, switching between tasks and managing your emotions all require sustained mental effort, Hulst says.
“We are constantly triggered by our emails, [by our] phones, by meetings, by messages, by conversations … often we are not giving our brains much opportunity to rest.”
This type of tiredness isn’t necessarily visible.
“So you just go on, and you’re not aware that you’re actually using your brain quite extensively.”
When you’re busy or stressed during the day, you might feel like you can’t stop and rest – but that’s the exact moment you should take a break, she says.
“Create a few moments without the demands – a chance to zoom out – and you can come back and think more clearly, prioritise better and work more efficiently.”
It can be easier to tell when someone else needs a break, so if you’re prone to pushing through, it might be worth recruiting a colleague, partner or friend to remind you to take a breather.
It’s important to remember that feeling mentally tired after a busy day is normal, but there’s a difference between that and burnout.
“When that exhaustion becomes too persistent or overwhelming, or really starts interfering with daily life, then it may be … something that deserves attention.”
How does stress affect the brain and what can we do about it?
Stress itself isn’t necessarily a bad thing, Hulst says, especially in the short term.
“It helps us to react, to focus, to perform when something important is happening,” she says.
But when that stress response is activated too frequently or for too long, it becomes a problem.
“Stress influences our cardiovascular response, our immune response, our hormonal systems. Over time, when stress becomes chronic, it means that all these systems can remain activated for prolonged periods, and that cumulative wear and tear is sometimes referred to as allostatic load.”
When everyday demands begin to affect sleep, exercise and eating habits, they impact your ability to recover.
“The effect of stress on sleep is very important, because during sleep it’s not that our brain just switches off, it is an active process of dealing with the information of the day,” Hulst says.
During sleep, your brain works to either reinforce or weaken information, so if stress disrupts your sleep, that affects this process and how well you perform the next day.
“We can’t remove all stress from our lives and that shouldn’t be the goal, but I think what matters is whether we have sufficient opportunities to recover,” Hulst says.
“Physical activity, good sleep, social connection and general downtime usually help.”
What can we do to maintain a healthy brain as we get older?
Being physically active, avoiding smoking, limiting alcohol, eating a healthy diet and staying socially connected all support a healthy brain.
And it’s important to monitor blood pressure, cholesterol, diabetes and hearing loss.
“From a scientific perspective, some of the most consistent evidence we have is for physical activity,” Hulst says.
“Older adults who are more physically active tend to have better cognitive as well as physical health. And obviously when you’re physically active, usually your cardiovascular system is healthier, and what’s good for your heart is usually good for your brain too.”
Should I be doing Sudoku or crosswords to train my brain?
Hulst says you should do Sudoku and other puzzles if you enjoy them, but becoming good at Sudoku in itself isn’t proven to improve brain health.
“I would much rather encourage people to think more broadly about how [to] keep your brain active, stay socially connected, curious and engaged with the world,” Hulst says.
Trying new activities is just as important for your brain as physical activity in general, she says. For example, if you’re a runner, increasing your running time will benefit your physical health, but won’t have as much effect on your cognitive health.
“There is value in learning something genuinely new, something that asks your brain to acquire a skill or approach information differently. It should be challenging enough that you are learning, but not so difficult that you give up.”
Learning new skills challenges your brain to form new connections or use existing connections differently. Over time, that builds cognitive reserve, which helps the brain cope with age-related changes or diseases.
That’s why you should be thinking about brain health when you’re young, Hulst says, though you’re never too old to start.
“The habits, experiences, environments that we’re exposed to throughout life all contribute to how resilient the brain is at later stages.”
I’m becoming more forgetful; do I need to be worried?
It’s normal to occasionally forget things when we’re tired, busy or stressed.
“What matters more is a clear and persistent change from how you normally function, particularly if it begins to interfere with everyday life,” Hulst says.
“That’s something worth discussing with a health professional. A sudden marked change in someone’s thinking or memory is different again and should be assessed promptly.”
Some of us just aren’t good at remembering some things, like people’s names.
“So if you’re 60 and you forget a name, then it’s nothing new – it’s just who you are and it’s probably nothing to worry about,” she says.
“When things really suddenly change, whether your partner or someone close to you is making comments about it, that’s usually when something is off.”
Professor Hanneke Hulst is giving a talk titled We don’t have a spare: keeping a healthy brain on August 25 as part of the University of Auckland’s Raising the Bar event.
Bethany Reitsma is a lifestyle writer who has been with the NZ Herald since 2019. She specialises in all things health and wellbeing and is passionate about telling Kiwis’ real-life stories.