When we think about nutrition, the conversation usually circles back to weight or body composition. But your brain has nutritional needs of its own, and meeting them affects how you think, feel, focus and sleep day to day. The foods that support your brain are some of the most rewarding to get right, and most of them are everyday items already in your weekly shop. There are a few key nutrients worth knowing about.
Fats
Fat is one of the most important nutrients for brain health: your brain is around 60% fat, much of it a special omega-3 called DHA. DHA forms a jacket around your nerves and helps the electrical messages from your brain stay targeted, which is why it is so important for normal brain function.
You will find DHA in oily fish such as salmon, mackerel, sardines and trout, whether fresh or tinned. Aim for two portions of oily fish a week. If you do not eat fish, your body can convert a small amount of the omega-3 in plant sources, such as flaxseed, chia seeds and walnuts, into DHA, but the conversion is limited. If you do not eat oily fish, a high-quality omega-3 supplement is worth considering.
Carbohydrates
Did you know your brain uses 20% of your daily calories even though it is only about 2% of your body weight? Your brain needs steady fuel to function, and carbohydrate, particularly glucose, is its preferred energy source.
Including carbohydrate-rich foods throughout the day helps keep your brain well fed. Choose high-fibre carbohydrates such as brown rice, wholegrain bread, jacket potatoes, high-fibre breakfast cereals, oats and pasta.
B vitamins
B vitamins have lots of roles to play when it comes to your nervous system, psychological health and how your brain metabolises nutrients.
Pantothenic acid (vitamin B5)
Pantothenic acid is really important for normal mental performance. Find it in salmon, chicken, avocado and mushrooms.
Vitamin B12
Vitamin B12 is essential for healthy nerves and normal psychological function. You will find B12 in yoghurt, milk, eggs, all kinds of fish and beef. B12 is only found in animal foods and fortified products, so those on plant-based diets need a B12 supplement.
Vitamin B6
Vitamin B6 helps to reduce tiredness and fatigue. Bananas are a great source of vitamin B6, and you will also find it in chickpeas, salmon and beef.
The gut-brain connection
One of the most exciting areas of current brain research is the gut-brain connection: the way your digestive system and brain talk to each other. The bacteria living in your gut play a much bigger role than we used to think. They produce many of the chemicals that affect mood and concentration, and research is increasingly linking gut health to mood, focus and even long-term brain health.
The practical takeaway is simple: foods that support a healthy gut also tend to support a healthy brain. That means eating plenty of fibre (aim for 25 g a day), varying the plants you eat (the target is 30 different plant foods a week) and including some fermented foods, such as natural yoghurt, kefir, kimchi and sauerkraut. The same way of eating that supports your gut turns out to support your brain too.
Check your iron
Being low in iron can affect your mood as well as how your brain functions. Symptoms of anaemia (low iron) can include:
- Weakness
- Feeling lightheaded or dizzy
- Increased heart rate or palpitations
- Pale skin
- Low mood or depression
- Shortness of breath or getting out of breath easily
These symptoms can be caused by other things too, so see your GP and get your blood tested before starting any iron supplements.
Low iron is quite common in Ireland, and you can feel tired even before you have full anaemia. You need to eat iron-rich foods at two to three meals every day. Foods rich in iron include:
- Red meat and liver
- Chicken legs and turkey legs (the brown meat)
- Iron-fortified breakfast cereals
- Nuts and seeds, such as almonds and pumpkin seeds
- Spinach and kale
- Lentils, chickpeas and beans
- Eggs
- Shellfish, such as mussels and cockles
Stay hydrated
Your brain is around 75% water, and even mild dehydration affects concentration, mood and short-term memory. Research consistently shows that being just 1% to 2% dehydrated can impair cognitive performance, and that is a level most people experience routinely without noticing.
Aim for around 2 litres of fluid a day for women and 2.5 litres for men, with more in hot weather or during exercise. Water is the foundation, but tea, coffee and milk all count towards the total. The simplest way to check your hydration is the colour of your urine: a pale straw-yellow colour is the target.
And sleep...
Nobody’s brain works well without sleep. You cannot always control how much sleep you get. Parents of small children and shift workers, you have my sympathy. But lots of people miss out on sleep without realising it. Most adults need seven to nine hours of sleep a night. If you are consistently in bed for only six hours, you are likely not getting enough sleep. Even going to bed half an hour earlier each night can make a real difference to how you feel after a few weeks. Common sleep saboteurs include screens too close to bedtime, caffeine after lunch, alcohol in the evening and inconsistent bedtimes (your body responds best to a regular sleep-wake schedule).