Monique Ryan, MS, RD
Consuming the right mix of foods and nutrients for training clearly supports your body's recovery and performance, but did you ever consider that food can affect your brain's performance?
Your brain is made of approximately 100 billion nerve cells called neurons, which gather and transmit electrochemical signals. For these brain cells to communicate effectively, they require chemicals called neurotransmitters. The connections between our neurons are constantly and rapidly changing and rewiring.
Although we all naturally lose brain cells throughout our lives, this does not necessarily accelerate with age. Loss of mental agility might actually be from the neuron's failure to communicate effectively. Neurotransmitters carry messages from neuron to neuron, and influence mood, thinking and sleep patterns.
Neurotransmitters are made from amino acids found in protein foods, and specific vitamins and minerals are used in this process. Three key neurotransmitters include acetylecholine, dopamine and serotonin.
Carbohydrates Are Brain Food
Your brain has very high nutrient and energy needs, with glucose being it's only fuel supply under normal and healthy conditions. Unlike your muscle cells, brain cells cannot store glucose and thus depend on a steady supply of this precious fuel, consuming about 120 grams daily. Glucose deficit, brought on by not eating enough, can cause confusion or dizziness—bonking.
From your morning meal onward, eating every three to five hours (plus more during hard training) seems to offset the up and down pattern of blood glucose levels.
Recent studies suggest consuming sports drinks during training delays brain fatigue or "central fatigue." When blood glucose runs low, there are increased levels of serotonin and adenosine in the brain, which causes fatigue, while there are decreased levels of dopamine, a neurotransmitter that increases focus and concentration.
You may have experienced the performance benefits of consuming caffeine during training, and many experts now believe that its adenosine-blocking effect on the central nervous system is what's most effective.
Carbohydrate intake during training also lowers blood levels of the hormone cortisol and increases insulin, which in turn decreases levels of ammonia in the brain and blood. Ammonia is toxic to the brain and also likely impairs muscle metabolism.
Other Nutrients for Brain Health
Water is good for your brain. The majority of your blood is water, and blood delivers nutrients to the brain. Much of your brain sheath is composed of fats. The healthy omega-3 fats seem to improve brain cell communication as well as regulate the immune system and decrease inflammation. Inadequate amounts of omega-3 fats can be associated with depression and other brain disorders.
The best sources of omega-3 fats are fatty fish such as salmon, sardines and trout. In contrast, too high an intake of saturated and trans fat from fatty meats, whole milk products and hydrogenated oils can lead to blockage of the arteries in the brain, just as they would in the heart muscle.
Your brain uses about half the body's total oxygen consumption. Free radicals, which are highly reactive substances and byproducts of oxygen use, may play a role in the deterioration of the brain. Antioxidant nutrients can deactivate these free radicals.
Beside vitamin antioxidants such as vitamin C, fruits, vegetables, nuts, seeds and grains contain thousands of other types of compounds called phytochemicals that contribute significantly to our dietary intake of antioxidants. Some potent sources include blueberries, blackberries, cranberries, raspberries, broccoli, oranges, red grapes, red bell peppers and kiwis.
B vitamins are also vital to normal brain and nerve function. Adequate amounts of vitamin B12 prevent brain tissues, spinal cord, and nerve degeneration. Good sources are animal foods such as milk, cheese, yogurt, and poultry. Vegans should consume B12 fortified foods or supplement with this nutrient.
Vitamin B6 or pyridoxine help convert tryptophan into serotonin, and is found in chicken, fish, pork, as well whole grain cereals, nuts, and legumes. Folic acid is essential for the metabolism of fatty acids in the brain, and is found in orange juice, leafy green vegetables, and dried peas and beans.
Clearly, following your mother's advice and eating a well-balanced diet and variety of nutrients is good for you. It's healthy for your body, and helpful for your brain.