How Food The Food you eat affects your BRAIN

The human brain is made up of some main macronutrients, first and foremost water then the next most abundant nutrient is actually FAT as well as then some proteins, amino acids, trace micronutrients and glucose. These component parts have a distinct impact on the function, development, mood and energy.

The post food sleepiness or late night alertness in part can be due the food you consume on a daily basis. The main weight component is FAT and it takes up nearly 60% of the brains dry weight (water removed). The fat in the brain comes in the form of essential fatty acids and of particular importance is omega 3’s – DHA (decosahexaenoic acid) and EPA (ecosapentanoic acid) which we have heard so much about in recent years. It is these omega 3’s that are the main component of our cell membranes or rather this is what we want our cell membranes (the cell outer layer) to be made of. If we consume good quality fats from our diet including omega 3’s, omega 6’s and healthy saturated fats our cell membranes get made of these fats which is fantastic for brain health. Eating bad, rancid fats like trans fats, bad saturated fats and industrial seed oils which are very inflammatory (canola, rapeseed, vegetable, sunflower etc) then our membranes get made of these fats which is bad. Our cells are always overturning and replacing the fats in our cell membranes so we need a constant supply of good healthy fats in our diet and a diet without this will lead to poorly made cell membranes.

The other diet that causes disruption in our brain structure and our cell membranes is a diet high in glucose, carbohydrate which not only causes irritation but also inflammation, insulin resistance. We only need a small amount of glucose for the brain to function well and we can make that ourselves so there is no actual need for glucose in the diet for brain function that does not mean that we cannot handle it but is it optimal? If we get our glucose from quality sources like fruits and vegetables (nutrient dense ones especially) then we can use this as fuel as well as keep our inflammation, hyper and hypo glycaemia at a minimum and reduce the risk of neurodegeneration (brain degeneration). A diet full of simple sugars, processed inflammatory carbohydrate foods and high in glucose will wreak havoc on the brain structure, cause inflammation but also affect our moods that have a high glycemic index (a indication of how quickly they turn to glucose in our blood) cause a much sharper increase in both blood sugar but also our need to respond with more insulin to quickly get the glucose out of the blood. Our bodies keep our blood sugar in a tight narrow range so they quickly want to get back to the norm of stable blood sugar. When eating fats because they are digested much more slowly and not full of glucose they do not cause this spike or sharp rise in blood sugar and insulin creating a more stable blood sugar profile.

Stable blood sugar can make us feel very well, focused and clear headed whereas when we have cycling or up and down blood sugar as with what occurs with high glycemic/high carbohydrate sugary refined food consumption we can feel that blood sugar rise and fall as do our moods, fatigue, mental clarity and much more. These ups and downs also wreak havoc on our systems in other ways by creating inflammation systemically and making our body work very hard to get rid of this excess blood sugar. By consuming a diet higher in fats we see the brain using more ketones instead of glucose for its functioning. Ketones are a high energy fuel that are designed specifically for the brain and are actually the brains preferred fuel source and increase mental clarity, cognition, mood and stabilise our brain function. Another way to raise ketones is to actually not eat or fast as this induces us to utilises the fat stores we already have break them down for fuel to send to the brain – not a bad thing, take that extra fat and fuel your brain sounds like a good idea to me. So get eating your omega 3’s, omega 6’s and healthy saturated fats. Generally we want more omega 3’s than 6’s and an abundance of quality healthy saturated fats. Omega 6’s can be out of balance with our omega 3’s if we consume to many or inflammatory forms of omega 6’s so be sure you get the balance right.

To find food sources of the above fats you can eat:

  • Omega 3’s – Wild Mackeral, Salmon, Herring, Tuna, White Fish, Sardines and Anchovies. Egg yolks, ground flaxseeds, hemp seeds, chia seeds, walnuts, cod liver oil and natto (fermented soy product).
  • Omega 6’s – good ones. Walnuts and walnut oil, poppyseeds and poppyseed oil. We need very little of these and the best way to get a balanced version is to eat animal foods that have a good omega 3 to 6 profile in them such as wild caught fish, pastured poultry and pork and grass fed beef and lamb products. If the animal is fed a natural diet – ex grass for cows, seeds and grass for chickens then its omega profile becomes very complementary for us so ensure your source of meat is high quality from grass fed animals, pastured non grain/corn or soy fed animals and wild caught fish and seafood.
  • Healthy Saturated Fats – coconut oil, coconut milk, grass fed red meat, pastured poultry, butter, lard, palm oil (sustainable source only), tallow and whole fat dairy such as butter, cream and milk-fat.

So don’t fear the fats, ensure your getting the right ones, good quality from good quality sources and in the right amounts. Decrease your processed, sugary high carbohydrate foods and you just might see your mood improve, cognition and mental clarity due to the brain being fuelled with what it loves best. For your brain focus on your quality healthy fats!


1. Acta Neurol Taiwan. 2009 Dec;18(4):231-41. Essential fatty acids and human brain. Chang CY1, Ke DS, Chen JY.




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