Optimise your focus, processing speed and memory with foods proven to improve brain performance.
Despite its relative diminutiveness, the brain uses around 20 per cent of your daily energy intake. Just as a low phone battery means you need to plug in, the brain needs constant recharging – and like a phone, it needs the right charger. “The brain is really sensitive to changes in its energy supply – because it needs a high amount of energy it’s really sensitive and vulnerable,” says Dr Therese O’Sullivan, senior lecturer in nutrition and dietetics at Edith Cowan University. “If the energy supply to the brain is cut off even for a short time you can get damage to the brain.”
Broadly, the fuels available to the body and brain are the three macronutrients, carbohydrates, protein and fat. The faster the breakdown of the macronutrient into simple sugars, the more quickly the brain can use the new energy. But faster isn’t better. While the brain can be impaired when it can’t access enough glucose – the brain’s preferred fuel and a by-product of macronutrient breakdown – it can’t thrive on foods that deliver glucose in one hit (think white bread and lollies).
To function well at work, the brain needs an injection of fuel after the night’s fast – in the form of breakfast. “The preferred fuel for the brain is glucose,” says Dr O’Sullivan. “When the blood glucose concentration falls below normal, hormones such as adrenaline and cortisol are released and that’s associated with feeling irritable so you get this difficulty in concentrating.” Consuming foods containing precursors to key neurotransmitters (amino acids found in protein) is also key to both mood and focus. Finally, hydration is also integral to optimal brain performance. Dehydration can impair short-term memory and the recall of long-term memory.
“The detrimental effects on cognitive performance occur once you’re at two to three per cent dehydration but you don’t actually start feeling thirsty until you’re about one to two per cent dehydrated,” says Dr O’Sullivan.
Start with slow-release carbohydrates found in wholegrain breads and cereals (think two slices of bread or one cup of cereal or oats). “Choose foods that have a low release of glucose throughout the day,” says Dr O’Sullivan. A balance of complex carbohydrate, fibre and fat in each meal or snack will help to regulate blood sugar, which when unstable can cause erratic moods and brain fog.
A morning coffee can assist with concentration, but accredited practising dietitian and author of Clean Separation, Kara Landau warns that it can interfere with sleep, which is also key to brain performance. Intake should be below 300mg a day (about two café-style coffees or three cups of instant), she says.
Protein is essential for afternoon focus. “Protein foods have a particularly marked effect on the release of dopamine, a hormone that makes you feel more alert and able to concentrate,” says Landau. Protein foods contain two key precursors to dopamine, which is synthesised in the brain. However, this production process also requires carbohydrate, to enable passage of amino acids across the blood-brain barrier.
Landau suggests eating a serve of protein with a small portion of low-GI carbohydrates such as brown rice, pasta or bread, which will also promote a steady release of glucose into the bloodstream.
Vitamin B1 (or thiamin) facilitates energy metabolism while B6, B12 and folate have been linked to cognitive function. In a study at Australian National University, participants who took vitamin B12 and folic acid supplements for two years showed greater improvements on short and long-term memory tests than those who didn’t take the vitamins. Iron is integral to concentration and energy. Good sources of B vitamins include beef, chicken, peas and beans. If you’re not receiving enough from your diet, supplements may be useful. For iron, try red meat, eggs and legumes. Avoid things that interfere with iron absorption including spinach, dairy products and tea and coffee at dinner time.