“I’m a neuroscientist – this is how I banish my brain fog”
Neuroscientist Dr Sabina Brennan shares seven ways she tackles brain fog, from forgetfulness and fuzzy thinking to problems concentrating.
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Neuroscientist Dr Sabina Brennan shares seven ways she tackles brain fog, from forgetfulness and fuzzy thinking to problems concentrating.
Brain fog happens to the best of us. Anyone who has suddenly forgotten why they came into a room, lost their train of thought, or grasped for a name that was on the tip of their tongue, will recognise this foggy feeling.
A recent survey by the supplement company Blue Iron found that one in five women (20%) experienced brain fog every day, and 94% at least occasionally. In one study, it’s estimated that women have 20% higher odds of suffering it than men.
“Brain fog isn’t a disease, disorder, or diagnosis in itself, but a sign that something is amiss,” says neuroscientist Dr Sabina Brennan, former director of a dementia research programme at Trinity College, Dublin, and author of Beating Brain Fog.
“Brain fog is often temporary, although its duration depends on the underlying cause and it can sometimes persist. Thankfully there are things you can do to alleviate or even eliminate it.”
Common symptoms of brain fog include:
Some people also feel:
“Even small impairments in any of the above can impact on your daily life – including your ability to do your job – and affect your relationships,” says Dr Brennan.
“People affected by brain fog will say things like ‘I just can’t think straight’ or “I have to keep rereading the same sentence as nothing is going in.”
“Often there’s no one single cause but a combination of factors,” Dr Brennan says. “Your brain is quite resilient but sometimes you can reach a tipping point, and one factor may push you over the edge and cause symptoms.
“Causes range from dehydration, poor nutrition, poorly managed chronic stress and insufficient or disrupted sleep to underlying health conditions.
“Often, finding the cause is a process of elimination – first of all you check your lifestyle factors such as sleep, stress, hydration, and nutrition. If issues persist longer term, it’s best to get checked by your doctor for some underlying health issue, such as a vitamin or mineral deficiency or thyroid problem for instance,” says Dr Brennan.
“I would stress that changes in mental functioning that come on very suddenly within hours need urgent medical attention as this could be a symptom of a stroke, along with slurred speech or facial drooping.
"Delirium as a result of a urinary tract infection (common in older people) can also cause mental confusion and requires urgent treatment.”
Brain fog can feel scary, as well as frustrating and exhausting, but it is different from dementia. “Lots of older people worry their mental fogginess is a sign of dementia, but the symptoms are quite different,” says Dr Brennan.
“Possible warning signs of Alzheimer’s disease, for instance, include a new or recurring pattern of getting lost in familiar places, repeating the same question or story within a short space of time without realising, or becoming disorientated as to time and place – not knowing where you are or what day or time it is,” she says.
“We are not talking about an occasional or one-off lapse, but changes that recur, become noticeable or begin to interfere with everyday life.”
So what can you do when brain fog strikes?
Dr Brennan shares the seven things she does to help clear her head and support her brain health.
“If I’m having problems concentrating or finishing a task, the temptation can sometimes be to push on through and get it done, but if my brain is really tired, I’ll take some time out,” she says.
“Your brain is working for you 24/7 and it needs some breaks. I take a break every 60 minutes if I’m concentrating hard, even if it’s only for five minutes – walking outside and taking deep breaths. If I need longer, I’ll do gardening which doesn’t require much mental effort.
“The brain doesn’t stop working when you take a break. When you allow it to idle or daydream, the default mode network – a group of interconnected brain regions – becomes more active. It helps us draw on memories, make connections between ideas and imagine possibilities, all of which support creativity and problem-solving.
“Stepping away from a task can therefore help clear the fog and allow you to return with greater clarity. Taking that break outdoors and including some physical activity can be particularly beneficial,” says Dr Brennan.
“If I haven’t been getting enough sleep, I reach a point where I know I’ve got to repay my sleep debt and catch up,” she says.
“Your brain continues to work while you sleep – sorting, prioritising and consolidating new information and connecting it with existing knowledge and experience. Sleep also supports the clearance of metabolic waste from the brain. This overnight processing helps explain why ‘sleeping on’ a problem can sometimes bring greater clarity, a solution or a new idea in the morning,” says Dr Brennan.
Brennan says that she would start going to bed earlier and even take a short nap of no more than 15 minutes in the early afternoon to help replenish her sleep.
“I’d generally recommend either a short nap of up to 15 minutes or a longer one of around 90 minutes. A brief nap can improve alertness while reducing the likelihood or entering deeper sleep, whereas waking after 30 or 60 minutes may leave you feeling groggy or ‘sleep drunk’.”
If you experience persistent insomnia, Brennan advises using cognitive behavioural therapy for insomnia, CBT-I, recommended as a gold standard treatment by the National Institute for Health and Care Excellence (NICE).
“CBT-I helps identify and reframe anxious thoughts about not sleeping which can help break a sleep-worry cycle,” Brennan explains. “CBT-I may also include sleep restriction – for example going to bed much later than usual in the short term, which is counterintuitive but it builds up sleep pressure so you fall asleep faster and wake up less often.”
Your brain is a thirsty organ. It’s made up of 73% water and inadequate hydration can contribute to brain fog.
“It’s really important to drink enough fluids – I don’t drink tea, coffee, or fruit juice so as water is my main source of hydration, I drink a couple of litres a day,” says Dr Brennan.
The British Dietetic Association advises adults drink 1.5 to 2 litres of fluid a day (8-10 200ml cups) and says that includes all fluids such as fruit juice, tea, coffee and soft drinks, as they are 85% water. Individual needs vary with activity levels and climate.
It’s important to do one thing at a time and really focus on it, especially as we get older. “Avoid multi-tasking – it’s a myth anyway,” says Dr Brennan. “When you ‘multitask’ essentially the brain is just rapidly switching between tasks and this comes at a cost in terms of speed and accuracy.”
When you’re doing a complex task, it can help to adopt a step-by-step approach so you don’t feel overwhelmed. Break it down into smaller chunks and turn those into a to-do list.
Get as much information as possible down on paper or use a smart phone or other device to support memory and provide reminders.
“This will help you think more freely and free up cognitive resources. Remove distractions by decluttering your home, your desk, and your laptop,” advises Dr Brennan.
“Brain fog impacts on your ability to ignore distractors or irrelevant information. By decluttering, you do much of the filtering for your brain, freeing up resources to support healthy cognition.”
Have a stash of easy “no brain” stuff to do for when brain fog strikes. “This allows you to feel productive even on bad days.”
“There’s no one superfood for brain health, but eating the variety of foods in the Mediterranean Diet is what I follow – so that’s wholegrains, lots of colourful fruit and vegetables, legumes, nuts, seeds and oily fish – not pizza, pasta, or red wine and very little red meat, saturated fats, and processed foods.”
Dr Brennan makes smoothies with frozen spinach, walnuts, frozen fruit, high-protein yogurt and almond milk, and makes vegetable soups with stock cubes, onions, and frozen vegetables, adds blended vegetables to homemade sauces, and makes salads with a variety of colourful vegetable, fruit and nuts.
Eating regularly is also important for brain function, she stresses, as the body will prioritise keeping you alive over cognitive function if food is in short supply.
“If my symptoms are persisting, I would ask my GP to investigate further to check for vitamin and mineral deficiencies, such as low iron levels and vitamin B12, which can both affect cognition, as well as hormone conditions such as underactive thyroid, which can slow thinking and other cognitive processes.”
Dr Brennan advises taking a diary of your symptoms to the GP to help them gauge the effect brain fog is having on your quality of life and if they are affecting you all the time.
Some tests your GP may want to consider include:
Both deficiencies become more common with age affecting 5% of 65 to 74 year olds and 10% of over 75s. Vitamin B12 deficiency can affect memory, concentration and other neurological functions, and may also cause abnormally large red blood cells.
Causes include autoimmune gastritis, which prevents adequate B12 absorption and reflux/heartburn medicines such as proton pump inhibitors, including omeprazole.
Dietary deficiency in B12 is uncommon but can occur in people following a vegan diet lacking adequate fortified foods or supplements. Folate deficiency may result from a poor or restrictive diet, alcohol misuse, and malabsorption conditions such as coeliac disease. Depending on the cause, deficiencies can be treated with tablets or injections.
Iron deficiency can contribute to brain fog, fatigue and difficulty concentrating. Iron is needed to make haemoglobin, which carries oxygen in the blood. A GP may order a full blood count and test ferritin, which reflects the body’s iron stores.
Treatment may include iron supplements, but it is also important to establish the cause of the deficiency.
Both an underactive and overactive thyroid can contribute to brain fog. An underactive thyroid gland can slow down physical and cognitive processes, causing slowed thinking and fatigue.
An overactive thyroid may cause poor concentration as well as anxiety, restlessness, sleep disruption and fatigue. Thyroid disorders can be identified through blood tests.
Underlying health conditions that can cause brain fog include autoimmune, chronic pain and inflammatory diseases such as lupus, fibromyalgia and Crohn’s disease, chronic fatigue syndrome, neurological conditions such as multiple sclerosis and migraine; depression and anxiety.
Others include endocrine or metabolic conditions such as an overactive or underactive thyroid and type 2 diabetes; perimenopause and menopause; and the lasting effects of illness, including long covid and post-sepsis syndrome.
Medication side effects may also contribute to brain fog symptoms. Drugs with anticholinergic effects block the action of acetylcholine, a chemical messenger important for attention, learning and memory and can impair mental clarity.
These include some sedating antihistamines, some medicines for overactive bladder, and tricyclic antidepressants such as amitriptyline.
If your symptoms have coincided with new medication, see your GP or pharmacist but do not stop taking prescribed medication without seeking medical advice.
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