Table of Contents
Introduction
The food we eat has a profound effect on how we function cognitively. Think of your brain as a very expensive car. Like a high maintenance car, the brain needs proper fuel, maintenance, and use to have peak cognitive function.
Proper cognitive function is the foundation of everything we do whether that be school, work, making decisions, exercising, etc. Every conscious and unconscious thing we do requires proper cognitive function, so why should we neglect foods that affect its function? Wouldn’t we want to be at our peak performance and give our all to the world we live in?
Recent studies have found that low glycemic (sugar) foods tend to increase attention span and improve memory. On the other hand, foods with a high glycemic index tend to decrease attention and concentration for the participants in the study 1. And if you think about it, this is obvious, remember when you were kids and ate a bunch of candy at one time? After that, do you remember how jittery you got and how difficult it was to pay attention to anything your teachers or parents said? This is why we see these trends on television and in real life, when little kids consume candy and jump around everywhere.
Now you may be wondering how sugar has anything to do with brain function? Well for those of you that haven’t learned glycolysis, krebs cycle, ETC and those fancy cycles just yet, we’ll lay it out here for you. (*Keep in mind this is just a bare summary of what is happening!*) When glucose first enters the body after you eat that Tootsie Roll, it goes directly to the bloodstream, where it is broken down or stored. If it is stored, it gets converted into fat for later use. If the body decides to use the glucose, it will break it down in the cytosol (outer layer) of the cell. From there it will move to the mitochondria (powerhouse of the cell) to be further broken down. After that the glucose derivatives are converted into ATP (energy source of all life) to be used. Now this is a very simplified version of what happens so don’t study off of this lol.
Once this ATP is converted it goes to various parts, but over 20% goes to the brain!2 That’s insane considering there are around 78 organs in the human body and 1 organ takes up that much energy!3
So now you’re probably wondering how the amount of sugar affects brain function? Well don’t worry we got you covered, we’ll explain below.
Effect of Healthy Food
Healthy food is always said to be better for our brain but why? Well, certain studies have found that diets high in vegetables and fruits such as the Mediterranean and Japanese diet have a reduction of depression in people over the course of a lifetime than those who eat a Western diet by almost 30%4. The possible reason for this according to researchers is the serotonin that is produced in your gastrointestinal tract. Serotonin is a neurotransmitter that is used to control emotions, help sleep, fluctuate appetite, and many other important functions. And over 95% of your body’s serotonin is produced in your gastrointestinal tract! So when you eat food that is “healthy” for you it provides your gut with good bacteria that line the walls of the intestine. This allows the proper production of serotonin to occur within the body.
Foods that are considered healthy for the brain include: fruits, vegetables, nuts, and whole grains. These foods provide minerals, vitamins, complex carbs, fiber, and protein for the body to function properly. Plants also contain phytochemicals which help give them their different colors. These phytochemicals provide the body with antioxidants and anti-inflammatories which can lower the chance of decline due to mental diseases. Not only this, but these foods contain lots of fiber within them which feeds the microbiome in the gut and as described above can help with serotonin release5.
Not only is eating healthy important, but eating regularly is also vital for brain function. This happens because blood sugar must be maintained at a regular level in order for the brain to function. With consistent blood sugar, the brain is able to stay energized. I mean if the brain consumes 20% of the body’s total sugar it better have a good supply! And what better to provide consistent blood sugar than whole grains, oats, and nuts which provide slow-releasing sugar in the body6.
Effect of Unhealthy Food
Eating unhealthy food can be quite easy, because of how “great” the food tastes sometimes. One of the major sources of “great” taste is sugar. If our body gets a taste of sugar, our body craves for more and it turns into a sort of addiction7. We know that addiction sometimes can be very difficult to overcome and if we continue to eat in an unhealthy manner our body and mind would desire more8. Initially, it would seem like a harmless desire and our innate response would be to quench the thirst for sugar. However, one needs to be careful to not continue feeding the addiction and to maintain ourselves to eat in a healthy way.
At a young age, we are shown sweets and we learn how it tastes. Then we desire to consume more of it even though we might not necessarily need it to keep functioning normally. The reward system that we have tends to require more and this leads to unhealthy consumption issues if not controlled properly9.
Studies show that younger children, as well as young adults, may have trouble controlling their desires for junk foods! The reason being is that the prefrontal cortex is still being developed in children and teenagers. The prefrontal cortex plays a huge role in our body, which involves many functions such as controlling emotions, restricting oneself, and maintaining awareness. Eating unhealthy foods that taste “good” tends to make this age range susceptible to developing an addiction. This is due to the fact that the brain believes that these foods are rewards and will work towards always obtaining these rewards. Research also indicates that sugar can impact one’s brain by damaging vessels in the brain and decreasing memory capacity10.
As briefly talked about above, diets high in sugar lead to higher levels of depression. Now this is because processed foods contain simple carbs and lots of sugar which tends to be broken down and put into the bloodstream very fast. This causes inflammation to occur within the linings of organs in contact with the sugar. (how)This inflammation is caused by excess AGEs (advanced glycation end-products) and insulin is released into the bloodstream. These both can lead to oxidative stress and overall inflammation increase once in the bloodstream, affecting vital organs11. Once inflammation has occurred proper serotonin cannot be produced, affecting your emotions, mood, sleep, memory, and other aspects of your body12.
Of course, unhealthy consumption of sugar also leads to other issues such as heart disease, diabetes, obesity, dental issues, and etcetera. Keep in mind that it is not only sugar, but other aspects of foods such as fats and calories need to be heavily considered as well to maintain a proper diet. This is why it is important to learn how to properly take care of your dietary needs and to not always give in to temptations. Not giving in to temptations in terms of diet might allow you to teach yourself how to better avoid other addictions that are harmful to your health. Try to avoid or limit consumption of sweetened beverages, fast/processed foods, refined grains, and etcetera13.
Studies on the Effects from Food
(source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2805706/)
This chart above is sourced by the study… shows that an increased amount of DHA could have led to the evolution of humans as we know it today. DHA is Docosahexaenoic acid which is a type of Omega-3 found in various foods. It is hypothesized that early hominids ate a lot of seafood which led to cognitive function increases over time. And this is proven with evidence from archaeologists who have found evidence of early hominids residing in shore-line habits where their primary nutrients would be fish.
On top of this, in recent history, specifically in western diets, the consumption of omega-3 has decreased and saturated fats have increased. This may be related to the increase in depression seen in western countries. As seen in the lower graph in the chart above, it shows the Asian countries that rely heavily on seafood have much lower levels of recorded depression than countries not as big on seafood. Not to say that everything we eat is bad, but maybe adding more seafood and lowering red meats, oils, and cheese may be beneficial to your overall health. I mean a nice baked salmon with some good seasoning is delicious, who would say no unless of course, you’re allergic which is a totally different story.
Within this study it was also found that rodents with low levels of omega-3 tended to have impaired memory and learning skills. This also translated over to humans as people low in omega-3 were found to have higher chances of severe mental disorders such as: ADHD, dyslexia, dementia, depression, bipolarism, and schizophrenia14.
To test this the researchers did a double-blind study on children where half received omega-3 supplementation and the other half did not. After 6-12 months the researchers tested the children’s coordination and cognitive function (through concentration and academic ability). It was found that the group taking omega-3 supplements performed higher than those who did not. There were a few other studies that tested the same thing in different ways with similar results that the omega-3 supplement group performed better. Now these studies aren’t set in stone as there could be many outside factors that could’ve influenced the results, but there seems to be some type of correlation.
This article also takes about previously done research that shows excessive caloric intake is also negative to cognitive health, even with healthy diets. It is even said that excessive food consumption in more modern countries is just as bad as lack of consumption in third world countries. The excess calories are released as sugar and stored as fat within the body which can cause inflammation and increased insulin production within the body. All of this will lead to problems in cognitive function as touched at above.
It is important to add that this research indicates that future studies may be able to further indicate ways to protect the brain from damage as well as improve overall cognitive function via diet. Never underestimate the small changes that you may make to your diet as it can have either favorable or detrimental effects to your body in the long term.
As we discussed, there are multiple factors that can affect the cognitive function within each of us. But the main takeaway is that excess sugar and fats such as saturated and trans fats can deteriorate the body and overall brain function. Try to change up your diet with more wholesome and nutrient-dense food if you want to be closer to the true potential of your brain!
Diets
There are a variety of tried and tested diets out in the world, and varying results for many! Key aspects that we think should be in your diets are the following. Attempt to consume a variety of vegetables and fruits as they provide a multitude of nutrients that help you stay healthy! Consume whole-grain foods over processed/refined types of foods, but do not overconsume these foods! Limit yourself to perhaps 1/4th of your meals with whole-grain foods. Have protein foods in your diet! Protein plays an essential role in developing our body, especially in the physical domain.
It is important to consume healthy protein foods, so try to avoid protein foods with many negative additives! Water is a key element in many diets, so attempt to mainly consume water as it is best in terms of hydration for your body and brain! And as stated above the Mediterranean and Japanese diets tend to be very good to lower depression and improve memory, so try those out if you can
Conclusion
Overall the key point is the food we put in our body affects the way we function, and the most important organ: the brain! So we should take it seriously how to properly nourish the brain and how to prevent preventable diseases from occurring. We hope this article gives a little glimmer on how the food you eat affects your cognitive performance, and hope you can take a bit of this to your daily lives!
By Kartik Goswami and Joel Varughese