The Franklin Institute created the Brain-Food Pyramid as an alternative to the USDA's former Food Guide Pyramid to help people visualize the nutritional requirements of the brain and better comprehend the effects of these nutrients on the brain. According to this guide, the brain requires all three of the primary macronutrients -- protein, carbohydrate and fat -- to function properly. It also requires antioxidants to defend itself from harm or dysfunction.
Healthy Fats
According to the Franklin Institute, two-thirds of the brain is composed of fats. The brain needs the fatty acids from healthy fats to produce brain cells. Fatty acids, the basic components of dietary fats, form the membranes surrounding brain cells through which fuel as oxygen, glucose and antioxidants passes in and metabolic waste passes out. Omega-3 ALA fatty acid, as found in flax, leafy green vegetables and cold water fish, and omega-6 LA fatty acid, as found in meat, eggs, dairy and certain vegetable oils, are considered essential fatty acids (EFAs) to obtain from your diet because your body cannot make them on its own. The body uses these EFAs to make the most abundant fatty acid in the brain, DHA. DHA is essential for the brain's functional and structural integrity, and a loss of DHA, says the Franklin Institute, can lead to cognitive and emotional impairment. Oleic acid, found in human milk, olive oil and certain other vegetable and nut oils, is one of the most abundant fatty acids in myelin, the protective sheath coating neurotransmitters. Myelin is made 70 percent of fats and 30 percent of protein.
Proteins
When protein is digested, it is broken down into its constituent amino acids, which it then rebuilds into the different types of proteins it needs to function -- namely, neurotransmitters, enzymes, chromosomes and hormones. Eight of the 20 amino acids are considered essential, as you cannot produce them on your own and so must obtain them from your diet. Complete dietary sources of all eight essential amino acids are called complete proteins and include meat, poultry and fish, eggs and diary. Incomplete proteins, containing only some of the eight, include grains, nuts, seeds and beans. A 2003 research review in the journal "Appetite" found that the amino acid tyrosine seems to prevent the significant decline in mood and cognitive performance associated with acute stress.
Carbohydrates
The same 2003 "Appetite" review also found that increased carbohydrate intake seemed to enhance mental acuity in soldiers undergoing extreme physical activity that involved a high expenditure of energy. When carbohydrates are digested, they are broken down mostly into glucose, a simple form of sugar that provides energy to the body and brain alike. Glucose is the brain's primary energy source, yet brain cells cannot store it. The brain therefore requires a steady supply of glucose be delivered to it through the bloodstream. An excess of simple or refined sugars, as found in many processed and packaged foods, however, can deprive the brain of glucose, the high blood sugar levels triggering the pancreas to produce insulin to store the excess glucose before it ever reaches the brain. This can deprive the brain of the energy it needs for such functions as concentration, learning and memory. Complex carbohydrates, as found in fruits, vegetables, legumes and whole grains, provide the brain a healthier and more sustained supply of glucose.
Micronutrients
The brain relies on antioxidants to protect it from damage and impaired function. Oxygen balance is vital to brain health, as it can be as detrimental to the brain as it is necessary. Certain forms of oxygen, called free radicals, can damage brain cells through a process known as oxidation. Antioxidants, as found abundantly in fruits and vegetables, neutralize these free radicals before they can cause any damage. According to a 2006 report in the "Journal of Nutrition, Health and Aging," vitamins C, D, E, K and the B complex as well as the minerals iron, copper, magnesium, manganese, zinc, iodine and lithium are all necessary for different brain functions.
References
- "Appetite"; Nutrition, Brain Function and Cognitive Performance; H.R. Lieberman; June 2003
- "Journal of Nutrition, Health and Aging"; Effects of Nutrients (in Food) on the Structure and Function of the Nervous System: Update on Dietary Requirements for Brain. Part 1: Micronutrients; J.M. Bourre; September/October 2006
- "Journal of Nutrition, Health and Aging"; Effects of Nutrients (in Food) on the Structure and Function of the Nervous System: Update on Dietary Requirements for Brain. Part 2: Macronutrients; J.M. Bourre; September/October 2006
- "Agricultural Research Magazine"; Nutrition and Brain Function; James A. Joseph; August 2007
