A healthy diet
plays a vital role in attaining optimal academic performance during
the rigours and challenges of exam time.
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 exams.
PROTEIN AND BRAIN POWER
Protein
consumed from food sources provides the body with amino acids, or
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 in 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 and
concentration levels and a reduced ability to transfer learning to
long-term memory.
Similarly,
consuming foods high in refined sugar will lower the levels of
neurotransmitters 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 consume.
There are two
primary forms of carbohydrates, complex carbohydrates and simple
carbohydrates. Complex carbohydrates are found in wholegrain
cereals, bread, pastas, fruit 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 drinks.
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 and able
to concentrate and commit information to memory more
effectively.
SUGAR BURN-OUT
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 uses 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 students are
nervous, 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.
•The writer is assistant professor in food science and
nutrition, University of Canberra.
•This article first appeared in The Conversation (http://theconversation.com), a website which carries
analysis by academics and researchers.