Exam time is quickly approaching for HSC and university students. While study is at the forefront, nutrition is often the furthest thing from students' minds. However, a healthy diet plays a vital role in attaining optimal academic performance during the rigours and challenges of exam time.
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Key foods and their components have been found to enhance cognitive function, improve mental alertness and enable sustained concentration to help students learn and remember the themes, concepts or formulas for their final exam.
Protein and brain power
Protein consumed from food sources provide the body with amino acids, or the building blocks, to produce key chemicals, such as neurotransmitters for the brain. Neurotransmitters are vital for brain cell-to-cell communication. Key neurotransmitters in terms of improved cognitive function and brain health include serotonin, norepinephrine and dopamine.
Serotonin, produced from the amino acid tryptophan, is found in brown rice, cottage cheese, salmon, red meat, carrots, peanuts and sesame seeds. It helps in the regulation of memory, learning and mood.
The amino acid tyrosine is involved in the production of the neurotransmitters norepinephrine, key to the transfer of memories to long-term storage, and dopamine, which is involved with improving motivation and activity. Tyrosine-rich foods include avocados, turkey, chicken, red meat, dairy, lentils, lima beans and sesame seeds.
The consumption of foods low in these amino acids, such as many "junk" foods, will result in low levels of serotonin, dopamine and epinephrine. This leaves students with lowered mood, concentration levels and a reduced ability to transfer learning to long-term memory. Similarly, consuming alcohol, caffeine and foods high in refined sugar will lower neurotransmitter levels such as dopamine, resulting in decreased motivation, mental dullness and an inability to focus.
Carbohydrates for sustained energy
Carbohydrates can provide sustained energy for mental alertness and concentration for those long study periods and for three-hour-plus exams. Glucose, the energy storage form of carbohydrates in the body, is the primary source of energy used by the brain. To ensure energy is sustained, students need to be careful which type of carbohydrates they are consuming.
There are two primary forms of carbohydrates, complex carbohydrates and simple carbohydrates. Complex carbohydrates are found in wholegrain cereals, breads, pastas, fruits and vegetables. Simple carbohydrates, as their name suggests, comprise single carbohydrate units such as glucose or fructose and are found in lollies, muesli bars, energy bars and drinks, and soft drink.
In the body, complex carbohydrates are absorbed a lot more slowly. The slower absorption rate means that energy is slowly released and available for a longer time. This allows students to be more alert, able to concentrate and commit information to memory for longer and more effectively.
Sugar burn-out refers to the impending "high" and subsequent "crash" after consuming foods containing high levels of simple or refined carbohydrates.
As the sugar from these foods is quickly absorbed by the body there is a rush of glucose into the bloodstream, creating a short burst of energy, a "high". The body (and brain) quickly use up this energy and the high is just as quickly followed by a burn-out or "crash", leaving the person feeling lethargic, irritable and sleepy. Learning is not committed to memory and come exam time information cannot be effectively recalled.
Sustaining nutrition for a long exam
To ensure students have energy for that exam of three hours or more, they should eat a light meal comprising carbohydrates and protein — for example, baked beans on wholemeal toast or an egg or tuna salad wholemeal sandwich — one to two hours beforehand.
If the student is nervous, then they should try a snack of vegetable sticks and hummus or wholemeal raisin toast around one hour beforehand. This way their body and brain will be fuelled to go. In terms of fluids, water is best.
Brain function is influenced by short-term and long-term dietary changes. For overall health and optimum academic performance it is better to consume a healthy diet comprising a mix of fruits, vegetables, meats, cereals and dairy over the longer term. If nutrition has not been a primary focus over the last couple of months, then making dietary improvements now can help towards students achieving academic goals.
Remember the healthier the food, the more effective your brain is at retaining information and the better you'll perform come exam time.
Tanya Lawlis is Assistant Professor in Food Science and Nutrition at University of Canberra. She does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.