It is often said that what you eat is what you are. Is there any truth in this statement? It turns out that there is much more truth in it than you might have thought. Foods play a big role in determining brain health, happiness, success, and overall quality of life. According to the Center for Disease Control and Prevention CDC), 5.3 million Americans were reported to have alzheimer’s disease in 2014. By 2060 up to 14 million Americans are projected to be affected. How can you avoid falling into this statistic? First let us review some basic brain facts. 

Quick Brain Facts 

  1. The brain weighs approximately three pounds. However, that does not mean big head = big brain = your so smart. Einstein’s brain was less than three pounds but how many people can you find that is as smart as he was?
  2. We are born with almost all of the brain cells
  3. We can grow new brain cells throughout our life through a process called neurogenesis
  4. The brain is mostly water. In fact 75% of it is water.
  5. If you should remove all the water from the brain, what is left is mostly fat (60%)
  6. The brain consists of three main parts, the cerebrum used for higher thinking and sensory perception, the cerebellum, for posture and balance, and the brainstem which controls autonomic functions such as body temperature regulation, breathing and digestion. 
  7. The brain is the hungriest organ in the body. It uses 20% of the oxygen we breath and 20% of the glucose that we get from food.
  8. To supply the brain with all the oxygen it needs, we have upto 100,000 miles of blood vessel highways, streets and lanes coming into close contact with all our brain cells. Do you know that 100,000 miles is equivalent to about 4 times the circumference of the earth?!
  9. You can feel your pulse in your neck if you place your fingers to the right or left of your throat. You are feeling your carotid artery which is the main artery taking blood to the brain. 
  10. Brain cells are so sensitive to oxygen deprivation that it only takes a minute of oxygen loss for them to start dying. After 3 minutes there is extensive brain cell damage. A coma is certain after 10 minutes and death inevitable after about 15 minutes.
  11. The brain is connected to every cell in the body via a complex nervous system consisting of the brain, spinal cord and peripheral nerve projecting in every direction throughout the body
  12. Brain cells are called neurons. They are an odd looking type of cell consisting of a cell body with tentacle-like structures sticking from it called dendrites, and a tail called axon
  13. Neurons do not touch. Information is transferred from one to the other using messenger chemicals called neurotransmitters 
  14. The brain is not fully developed until you are about 25-30. Before that, your prefrontal cortex, which is used for rational thinking, is still developing. Ever wondered about the silly or crazy things you did when you were a teenager?  
  15. The brain is plastic and adaptable. It continues to make new connections as you learn, and disconnect or prune neurons that you don’t use. This is known as neuroplasticity 
  16. One of the best ways too grow new neurons is to do aerobic exercise  
  17. Brain cells are destroyed by natural aging, free radicals, disease, stress, trauma, drugs, and poor nutrition   

Neurotransmitters and Brain Health

The function of neurotransmitters is to transfer messages from one neuron to the next. These include GABA, glutamate, endorphins, serotonin, dopamine, norepinephrine and acetylcholine. Let’s talk about the last four. 


Serotonin is a well-being and happiness neurotransmitter responsible for putting you in a good mode. It makes you want to get out, meet people and socialize. It also affects memory, digestion and restfulness while you sleep. A lack of serotonin is associated with low mood, low self esteem, anxiety, ant-social behaviour, difficulty sleeping, and poor memory. 


Like serotonin, dopamine is a feel-good neurotransmitter. It makes you feel motivated, attentive, alert and ready to learn. Too little of it will cause you to have a lack of interest in life, poor motivation, mood swings, feeling of hopelessness and inability to concentrate. 


Norepinephrine (also called noradrenaline) is a neurotransmitter that boosts your attentiveness and alertness. A lack results in attention deficit, anxiety and depression. 


Acetylcholine is responsible for muscle movement. So if you can walk, jog, cycle or even lift a pen, thank acetylcholine. Lack of it results in fatigue as well as memory loss, poor comprehension and difficulty calculating numbers. 

Nutrients and Brain Health

Now you can see that neurotransmitters affect not only brain biology but also our reality. Hence it is essential to have enough of each of them to ensure a good quality of life. Like the rest of our body, neurotransmitters are made from the food we eat. For example, tryptophan (an essential amino acid), B6, B12 and folic acid are needed to make serotonin; magnesium, folic acid and B12 are needed to make dopamine and norepinephrine. Apart from the neurotransmitter-building molecules, what other nutrients do we need for brain health? Let’s talk about a few. 


Remember that the brain is 75% water. Dehydration affects the balance of electrolytes (minerals) in and outside of your brain cells, which can affect memory, mood and concentration. It’s not surprising then that you might feel a bit irritable and unable to concentrate well when you are dehydrated.

Omega 3 Fatty Acids

Minus the water, the brain is 60% fat. The majority of that fat is in the form of the omega-3 fatty acids docosahexaenoic acid (DHa) and eicosapentaenoic acid (EPA). These fats have been found to help in brain development and cognition. EPA and DHA are mainly found in fatty fish like tuna, mackerel, trout and salmon. Plant-based food are not a good source of EPA and DHA. However, some contain high amounts of alpha linoleic acid (ALA) which can be converted to EPA and DHA. Plant foods with high ALA include flax seed, walnut, tofu and chia. Lack of omega-3 fatty acid in the diet has been associated with lack of attention, inability to concentrate, poor memory, mood swings and anxiety. 

Vitamin D

Vitamin D is a fat-soluble vitamin. It can be made by our bodies with the help of sunlight. However we do not make enough to supply all of our needs. Meat and meat products are good sources of vitamin, D but you can get enough from eating foods that are fortified with it. For example, orange juice, soymilk and breakfast cereals are vitamin D fortified. Deficiency in vitamin D has been found to cause cognitive decline in the elderly and depression. 

Vitamin E

Vitamin E is an oxidant that protects brain cells from damage and is reported to reduce the risk of alzheimer’s disease. 


The presence of fiber in foods slows down the rate of digestion and hence glucose release into the blood. This helps to supply steady glucose for longer periods compared to consuming high-sugar foods that are metabolized quickly leaving the brain hungry shortly after eating. For good brain health, look for nutrient-rich foods containing fiber.  

Phytochemicals and Brain Health

Phytochemicals are a group of chemicals in plants that do not provide any nutritive benefit but have been found to prevent cellular damage and protect against diseases including cancer. They are numerous and include the carotenoids, polyphenols and alkaloids. Their primary function is to protect plant from pests, uv radiation and disease that could compromise their survival. However, when we eat foods containing phytochemicals, we get several benefits including reduction in inflammation, slower progression of cancer growth, enhanced immune function and protection from bacteria and viruses. 

Foods That are Bad For the Brain 

Well, so far we have talked about what nutrients are good for the brain and what we need to get more of. But, are there some to avoid? It turns out that there are a few. Regular consumption of sugary drinks have been found not only to increase obesity and insulin resistance, but also play a role in increasing alzheimer’s disease. Sugary food consumption leading to increased visceral (belly) fat has been associated with brain tissue damage. Trans fats and saturated fats are also found to produce some negative effects on the brain such as reduced brain volume, memory loss, increased cognitive decline, and increased risk of alzheimer’s disease. 

Eating for the Brain 

Now that you know the good and the bad, what to dish and what to dump, it’s time to start eating healthy. But know that eating to feed the brain is no different from eating to feed the body. Whatever is good for the body is good for the brain. Therefore continue to follow the basic principles you have learned to keep your body healthy. That is, eat a variety of foods, eat adequate calories, and eat moderately. 

Courtney Simons
Courtney Simons is a food science professor. He holds a BS degree in food science and a Ph.D. in cereal science from North Dakota State University. He also holds Masters degrees in both Environmental Science and Instructional Design from Wright State University.
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