Optimising Brain Function with Nutrition

The sixth chapter taken from the Academic Success Formulais written by Kim Bjarnasson, an experienced nutritionist, who teaches courses that focus on the importance of optimum nutrition for the mind. Throughout the chapter, Kim discusses the role of nutrition and how what we eat influences how we think, feel and overall success levels. She looks in-depth at the role of glucose and fructose, the impact of stress as well as some general guidelines for eating well.

What are the ideal conditions for academic success?

There are a lot of factors that come together in order to create the ideal conditions for academic success. Knowing how to set a goal and devising a plan to achieve it, having a positive mindset to envision success and learning in the right environment just names a few. However, these skills can be hugely compromised unless our brain and body is given the fuel it needs to function optimally.

Even though there isn’t a one size fits all recipe for everyone to follow, a holistic and integrated approach is a great way to build a solid foundation to nourish the mind and body, in turn building academic success. Normally this consists of plenty of exercise and sleep, minimising stress and eating nutrient dense food. Put simply, what we eat influences how we think and how we are- food is simply the external internalised.

The Problem

The importance of diet has never been such a relevant topic for students. According to the Dietary Guidelines for Americans 2010, the top three sources of calories for kids aged 2-18 are grain-based desserts, pizza and fizzy drinks. Scarily, for the 14-18 year-old demographic, the number one intake of calories is from fizzy/energy drinks. It doesn’t stop there. Further research conducted in Perth, Australia, confirmed that eating a nutrient deficient diet during important developmental periods such as adolescence can have long term consequences. The study revealed that there was a huge difference between teens consuming a ‘Western-style diet’ of takeaways, fried foods, processed meats and soft drinks, to those eating a ‘healthy diet’ of whole grains, legumes, fish, fruit and leafy greens. The teens who were eating a healthy diet scored much higher on cognitive performance tests in maths, reading and comprehension, highlighting the true impact of diet in relation to academic success.

The Fructose- Glucose Effect

When looking at eating a nutritional diet it’s important to start to understand what is actually going into our food and bodies. With consumption of refined carbohydrates taking up 50% of our daily calories, research over the last five years has revealed that it’s the calories from sugar-sweetened beverages that are so harmful to our physical and mental health.

In fact, glucose disrupts our body’s natural PH (7.4) making it more acidic, which throws off delivery to cells as well as disrupting mineral absorption and balance. If this wasn’t bad enough, sugar can also encourage cravings that are similar to substances of abuse such as cocaine and alcohol. On the other hand, fructose intake can’t be used as energy like glucose, and instead is metabolised into triglycerides (fat), free fatty acids and uric acid which contributes to high blood pressure, obesity and insulin resistance. This combination can cause a whole host of issues, one of them being that our brain doesn’t know when our stomach is full and should stop eating. This can result in the tendency to overeat, and of mostly refined carbohydrate-rich foods.

Even though the realm of nutrition plays a crucial role for optimal brain function, it’s important to discuss a few other important ingredients for optimal cognitive function and academic success.


With heaps of research on the link between cognitive function and stress, it’s something not to be taken lightly. With so many students experiencing chronic stress due to busy schedules, lack of sleep and poor nutrition, it’s important to realise this can cause cellular changes in parts of the brain used for focused attention, perception, short-term memory and learning. Cortisol and adrenaline are released during times of stress, which can trigger a physiological cascade that shuts down the digestive and immune systems to name a few.

Scarily, many people spend a lot of the day under chronic stress – i.e. ‘running on adrenaline’, which means operating without the full function of all the body systems. This means we’re eating without proper digestion, so food can’t be broken down properly and the nutrients are unable to circulate the body to feed the cells. Poor cellular function means the brain isn’t getting what it needs for optimal development and processing.


Counteracting stress with exercise is a great way to improve health as well as levels of success. In fact, aerobic exercise increases blood circulation, which in turn means a greater distribution of nutrients. It’s also been proven to strengthen neural plasticity, especially in areas of the brain focused on learning, memory and deep thinking.

General Guidelines

Even though eating well can seem pretty complicated due to the vast amount of information out there, following a few general guidelines can easily promote brain function, general health and nutrition.

  • Eat the rainbow: Eat as many colours as you can, preferably from non-GMO fruits and vegetables.
  • Limit refined whites: Replace white salt, sugar, and flour with whole grains and brown varieties.
  • Limit processed foods: Avoid processed foods, especially those with more than five ingredients, or ingredients you’ve never heard of.
  • Reduce consumption of fizzy drinks and fruit juice: Reducing or removing these drinks from your diet and saving them for special occasions will do your body the world of good. Replace them with water, whole fruits and vegetables.
  • Avoid industrially raised/produced animal products: Replace with grass fed or organic varieties to ensure your body is getting the nutrients it needs.
  • Replace refined vegetable oils : Use butter, coconut oil and olive oils instead of sunflower, safflower and corn oils to reduce contact with GMO crops.
  • Employ the 80/ 20 rule: Put simply, this means doing right by your body 80% of the time and being a bit more lenient the other 20% of the time. Don’t deny yourself your favourite treats, just save them for special occasions.

The importance of real food

On the way to academic success it’s crucial to remember just how important real food is. Creating the ideal biological environment for success isn’t hard, it just takes a little redirection. The food industry has tried to convince us that it can provide everything our body and brain needs better than nature can. There are a lot of additives, preservatives and other chemicals being put into our foods, most of which don’t benefit or nourish us at all. The right combination of macronutrients (protein, fats and complex carbohydrates) and micronutrients (vitamins and minerals) is what’s really essential to the growth and development of the brain.

For detailed information on the realm of nutrition, including a in-depth breakdown of Macronutrients and Micronutrients, refer to the rest of the chapter titled Optimising Brain Function with Nutrition, in the Academic Success Formula.