Background Information
Fatty Acids and Evolution of the Modern Human
Scientific discoveries have confirmed that life originated in the seas where omega-3 fatty acids were abundant. As the modern human brain evolved, it too was influenced by the fatty acids. Evidence supports the fact that species were able to develop larger brains once omega-3 fats from food supplied by the sea and omega-6 fats from plants and seeds were available as a food source. One very noticeable difference in the species was the size of the brain. The change in the brain size was attributed to the fact that seventy percent of their food's nutrients were for brain development. 10 A major change occurred in the human brain about 200,000 years ago, which resulted in some human brains becoming larger than those of other mammals. Scientists found that populations who lived near oceans and consumed seafood that was rich in DHA (docosahexaenoic acid, a major contributor to brain growth) had larger brains. 11 People who lived in the interior areas and consumed meat from animals common to the area had smaller brains, about the size of a chimpanzee, for approximately 3 million years longer. 12 Stephen Cunnane, a professor of nutrition at the University of Toronto called the study "an important finding" that supports a theory that DHA from seafood boosted the brain power of early humans, and gave them the excess energy and nutrients they needed for brain growth. 13
Fats Impact on Brain Development and Function
The brain begins a process of protection during prenatal development known as myelination. This process continues until the cerebral cortex is fully formed. Myelination involves fatty acids that are incorporated into the brain's structure. This process involves thin layers of fat wrapping around axons (axons are cellular processes that extends from a neuron and link to other neurons). 14 Myelin formation is critical to the development of children's brains. Damage or unprotected nerve fibers can impact future intelligence of a child. 1 5 The myelin covering has a double job to protect the brain cells and to help these cells communicate with one another. The myelin covering provides cells with more rapid passage of signals that are transmitted by the brain cells. Communication between nerve cells occur at the synapse (a gap or space between neurons where one nerve cell can communicate with another): this space could be compared to a gap in a spark plug. Chemicals called neurotransmitters (chemicals that allow communication between nerve cells) are released at these gaps, these chemicals travel through the synaptic cleft (the space between neurons) until they meet the surface of their targeted neuron. The targeted neuron contains receptor sites for a specific signal. Evidence has shown that fatty acids have a great influence on the "docking" of neurotransmitters with their receptors, the receptors are held in place by phospholipids and fatty acids. 16 If the myelin covering becomes damaged the sending neuron cannot properly dock at the desired receptor site, thus exposing the brain cells to signals from other brain cells that they are not normally exposed to. When this happens the brain can experience an "electrical short circuit." 17 This loss of an electrical signal can result in disruptions with our motor control, bodily functions and cognitive skills. The process of myelination begins with the motor and sensory brain cells that give children the ability to complete specific tasks such as coordination, speech, control of arms and legs, crawling, walking and eventually higher order thinking. If the brain does not have the needed fat for this process to occur, our cognitive abilities are affected. These fatty membranes covering the axon are made up of 75 percent fat derived from essential fatty acids. 18 Sixty percent of our brain's structure is composed of fatty materials that must be supplied by our diet.
When we use our brains to come up with ideas, biochemical processes are occurring. Every time our bodies respond to some stimulus, a neurotransmitter has been activated by our brain. Neurotransmitters are supplied by the foods we eat. 19 The foods we consume have a direct affect on how well our brain performs. Eating a well balanced diet that contains essential fats and specific carbohydrates can provide mental sharpness, emotional stability, enhance memory, and aid coordination and balance.
Fats help regulate messengers in the brain that impact our immune systems, circulatory system, inflammation, memory and mood. 20 If your diet consists of foods that can be broken down into fatty acids, then brain cell membranes can form properly. The formation of these cell membranes is what allows nutrients needed by the brain to enter the cell body for the cells proper functioning. Properly formed cell membranes also allow metabolism to occur within the cell. The metabolic process is what allows waste to be removed from the cell ridding it of harmful toxins that could impair the function of the neurons. The membranes that make up the brain cells must be soft and flexible so the chemical messengers can move into the cell. Thus, the essential fatty acids omega-3 and omega-6 are needed to ensure the cell membranes or the myelin stay flexible and soft. Diets that are deficient in omega-3 and omega-6 fatty acids, but high in saturated fats and trans fats can cause problems for nerve cells. If we want to determine whether our diet is deficient in essential fatty acids we need to look at the membrane covering our nerve cells. 21 Brain cells formed under optimal dietary conditions have a composition that is 30% protein and 70% fat. Oleic acid is a fatty acid found in myelin, which is used by oligodendrocytes (a type of glial cell that produces myelin and maintains a healthy nurturing microenvironment for neurons). 22 This fat is found in breast milk and foods that contain mono-unsaturated fats, such as olive oil, peanuts, almonds and avocadoes.
Many western diets do not contain high levels of omega-3 fatty acids, polyunsaturated fats, or mono-unsaturated fats. Instead they tend to be high in omega-6 fatty acids, saturated fats, and trans fats. Polyunsaturated and mono-unsaturated fats are fats that remain in a liquid state when allowed to sit at room temperature, saturated and trans fat tend to become solids. Omega-6 fats are fatty acids that are derived from plants and seeds that include safflower and corn oil. Although omega-6 oils are desired fats, we tend to consume them in overabundance, which places the brain at a disadvantage because the ratios of omega-3 and omega-6 fats are out of balance. For the brain to get the maximum benefit from these two fats, they need to exist in a 1:1 or 2:1 ratio. Most of our diets actually have a 20:1 ratio with the omega 6 fats being twenty times higher than our omega- 3. Combinations of trans fats, saturated fats, and an overabundance of omega-6 fatty acids can produce chemicals that are inflammatory for the brain. 23
Brain fats help to keep the brain in a fluid state much like engine oil keeps your car's engine running smoothly. If the oil level in the engine drops too low it can be damaged. If the brain's fat level drops too low our mental, emotional, and physical well-being are adversely impacted. When our dietary fats consist primarily of trans fats, saturated fats, and too much omega-6 we began to experience problems with our mood, cognition, and the health of the brain from a long-term standpoint. A proper balance between omega-3 and omega-6 fatty acids has been given credit for our creative and highly technical society. However, if our current dietary trends persist as it relates to fats, we may be setting ourselves up for serious changes in the structure and physiology of our brains. These imbalances have been attributed to the alarming increases of brain disorders and depression among many of our children. Studies are also providing evidence that omega-3 fatty acids are also beginning to impact the brain on a genetic level. 24 The food we eat impacts the brain's "fatty architecture" from our childhood to old age. 25
What are Fatty Acids?
Fatty acids are compounds made from long chains of hydrocarbons that have a carboxyl group (COOH) on the end of their hydrocarbon chain. The carboxyl group is what makes the fat an acid. Fatty acids are the simplest type of fat. Fats can be classified as saturated or unsaturated. Saturated fats have a carbon chain that has an equal number of hydrogen atoms. They are considered to be saturated with hydrogen. These fats are solids at room temperature because they exist in straight chains that can be packed very close together.
Unsaturated fats have two carbon atoms that are connected by a double bond; they have
two hydrogen atoms missing. Unsaturated fats are liquid at room temperature because they bend and cannot be packed close together; they are referred to as oils. The shape of unsaturated fats is determined by the number of missing hydrogen atoms. As the number of missing hydrogen atoms increase the unsaturated fat bends more creating more fluid oil. If an unsaturated fatty acid contains one double bond it called a monounsaturated fat. Unsaturated fats with multiple bonds are called polyunsaturated fats.
Polyunsaturated fats can be changed by adding hydrogen, in a process called "hydrogenation." In hydrogenation, unsaturated fatty acids are converted into saturated fatty acids, but also (as a side product) unhealthy fats called trans fats are formed. During the hydrogenation reaction, the unsaturated fat is saturated by addition of hydrogen across the double bond. This process is accomplished by heating the oil to high temperatures and adding "pressurized hydrogen gas and a nickel catalyst." 26 Once the process is completed a fat known as a partially hydrogenated vegetable oil is created (PHVO). Hydrogenation changes the shape of a polyunsaturated fat from bent to straight. The chemical structure of trans fats mimic polyunsaturated fats, but the straight shape allows it to be packed close like a saturated fat. The body perceives these fats as a polyunsaturated because of their chemical structure, but has trouble using them. These unnatural fatty acids are found in margarine and vegetable shortening. They are known as trans fats and are not good for our brains. Trans fats can replace flexible insulating fat on myelin in animals, with hard coverings on nerve cells. These hard inflexible coverings were found to prevent proper communication between neurons. Scientists have been able to establish that increased uptake of trans fats in humans result in cognitive decline. 27 Trans fats also deplete omega-3 essential fatty acids, which are important for brain development and function.
There are three main omega -3 fatty acids of importance for optimal development of our brains. First is alpha-linolenic acid (ALA). This fatty acid is the parent for the formation of omega-3 fatty acids and cannot be made by our body (therefore, it is an essential fatty acid). DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) are known as the fish oils and derive their names from Greek because of the number of carbons they have in their chemical structure. The brain can make its most abundant fat DHA from ALA; however the production of this fat is not sufficient so most of it must come from the food we eat. Studies have confirmed that low levels of DHA result in a decline of the brain's structural and functional integrity. Increased levels of DHA have been associated with significant increases in mental intelligence among children. Breast milk that contained high levels of DHA was shown to increase IQ 3.2 points and enhance cognitive development in infants. Overall intelligence tests of breast fed babies from this group revealed that language abilities, problem-solving, and memory were higher. Infants who were deficient in DHA had lower overall intelligence test. Decreases in DHA have been associated with increased depression in individuals. 28 Countries eating large amounts of fish have lower rates of depression. DHA is also important to synapses, which have high concentrations of this fat in their membranes. Deceases in DHA in synaptic membranes can cause poor neuron function and death of neurons. 2 9Foods rich in ALA are walnuts, sea vegetables and green leafy vegetables. The main fatty acid for omega-6 fatty acids is linoleic acid (LA). Food sources that provide these fats are seeds, corn oil, sesame oil, safflower oil, and sunflower oil.
Carbohydrates and the Brain
Inflammation of the brain causes a reaction known as oxidation. Oxidation creates substances called free radicals. Free radicals take electrons from other molecules, which can cause damage to the brain. If the level of antioxidants is less than the free radicals brain cells can be damaged. The fat and protein components of brain cells can be damaged if our diet does not provide fuel for the brain from whole grains, fruits, and vegetables. These foods contain large quantities of complex carbohydrates. When the diet is full of simple carbohydrates, adequate fuel for our brains defense system is not provided. Damage from free radicals can result in damage to our DNA, which alters our genetic expression at some level. Thus, ensuring that we have dietary substances that promote antioxidant defense ensures optimal function of our brain and prevents damage to our genetic material.
Where Do Carbohydrates Come From-Photosynthesis
Plants undergo photosynthesis which allows them to take in carbon dioxide and give off oxygen. When this exchange occurs in plants carbohydrates are produced. The sun's energy changes the products and by-products of photosynthesis into useful chemical energy for humans. Plants transform carbon dioxide (CO 2) from the air, water (H 2O) from the ground, and energy from the sun into oxygen (O 2) and carbohydrates, (C 6H 1 2O 6) (6CO 2) + 6H 2O +energy = C 6H 1 2O 6+ 6O 2). 30 Carbohydrates have a tendency to form a ratio of 1:2:1 of carbon, hydrogen, and oxygen.
Metabolism of Carbohydrates
The main function of carbohydrates is to supply energy for the body, with emphasis for energy placed on the brain and nervous system. In order for our brain to utilize carbohydrates they must be broken down into glucose. The carbohydrates we consume must be "metabolized" to produce energy. Metabolized carbohydrates produce oxygen, carbon dioxide, and water, and energy. The body uses the energy and water but gets rid of the carbon dioxide. For metabolism to occur carbohydrates must be digested, absorbed, and undergo glycolysis (process that metabolizes carbohydrates to produce the high energy molecule adenosine tri-phosphate - ATP). Amylase helps breakdown carbohydrates for digestion.
Categories of Carbohydrates-Simple and Complex
Carbohydrates are classified as complex or simple. The chemical structure of the carbohydrate and the rate at which digestion and absorption occur determines the classification. Both simple and complex carbohydrates are made from atoms of carbon, hydrogen, and oxygen. Simple carbohydrates have either a single or double sugar unit. Single sugar units are called monosaccharides and double sugar units disaccharides. Glucose is the most common monosaccharide, and the main type of carbohydrate used and stored as energy by the body. Fructose, another common simple carbohydrate, is found in fruit, honey, and high-fructose corn syrup (which is manufactured). Galactose, another common monosaccharide, is not found naturally. Galactose tends to combine with glucose and form lactose known as "milk sugar". Because glucose is the main source of energy for the body some simple carbohydrates are needed in the diet. Fruits and dairy products are good sources. Refined carbohydrates such as white sugar, powdered sugar, candy, and brown sugar have little nutrient value and are digested and absorbed very rapidly compared to natural dietary simple carbohydrates. Refined sugars form alpha bonds (a bond where the OH group is located on carbon #1below the carbon atom) which can be broken easily by the human body and accounts for the rapid production of energy. Lactose or dairy products form beta bonds (a bond where the OH group is located on carbon #1above the carbon atom) and are not digested as easy by the body, thus they take longer to be digested and release their energy slower than refined sugars.
Fruits also have a slower release because they contain fiber which cannot be digested by the body.
Complex carbohydrates are also known as polysaccharides. They are long chains of simple sugar units. (Long chain molecules made from repeated units, such as polysaccharides, are called polymers.) The three complex carbohydrates that are important nutritional sources are fiber, starch, and glycogen. Starch and glycogen contain alpha bonds and can be digested to release energy. Starch is the main digestible form of complex carbohydrates. When enzymes, such as amylase, act on starches, they break their alpha bonds and released smaller carbohydrates such as glucose. In the body, when glucose is released from carbohydrates, some of this glucose is used immediately to produce energy. Any unused glucose is stored, by chemical conversion into another polymer called glycogen, or converted into fat. Glycogen also has alpha bonds, but it contains many branches, which allow it to be digested quickly when digestive enzymes act on it. Fiber is the third type of complex carbohydrate. Dietary fiber is not easily broken down as it enters the large intestines, because digestive enzymes cannot break its bonds. Some fibers are indigestible and others are digestible. Indigestible fiber will not dissolve in water. The fibers considered to be indigestible are cellulose, hemicelluloses, and lignins. Cellulose has a straight chain of glucose molecules held together by beta bonds. Food sources include whole-wheat bread, bran, and vegetables. Hemicellulose is composed of galactose, xylose, and glucose, and other monosaccharides and form polymers. They are found in whole grains and bran. Lignins are non-soluble fibers that contain alcohols, acids, and a woody type fiber. They are common in fruits, seeds, vegetables, and wheat bran.
Soluble fibers will dissolve in water and swell up. Although they cannot be digested they can be metabolized and fermented by bacteria found in the large intestines. Pectins, mucilages, and gums are soluble fibers. Pectin is used in jams and jellies because it forms a gel when water is absorbed. Pectin contains galacturonic acid and other monosaccharides. Citrus fruits, apples, strawberries, and carrots are common food sources. Mucilages and gums are similar in structure; both contain galactose and other monosaccharides. However, mucilages also contain manose and gums contain glucuronic acid. Gums are found in legumes, oats, and barley.
Consumption of fiber causes a slow release of glucose during digestion and absorption. Glucose is used by the brain and body to provide energy to cells. On the other hand, simple carbohydrates that have been refined are broken down quickly by the body, which can result in spikes in blood sugar. Rapid elevations in blood sugar can lead to overproduction of insulin. When too much sugar forms it can lead to obesity and health problems because of the continuous rises and dips in glucose and insulin concentrations. The brain needs a slow steady release of energy in order for it to function at an optimal level. Aggressive behavior and poor attention have been credited to children who had diets that were high in sugar. The correlation between serotonin and carbohydrate-insulin responses has been suggested as a possible reason for the aggressive behavior. If the serotonin levels were low the individual tended to have a propensity for aggression. 31
Glucose must be supplied for the brain to function; however, the type of carbohydrate consumed to provide the glucose is important. Nerve cells do not have the ability to store glucose like the muscles of our body, so glucose must be constantly supplied. When the brain receives too much sugar, it causes a decrease in the glucose available for energy instead of a surge; because the sugar is absorbed at a faster rate resulting in lower glucose levels. Simple sugars result in depletion of the energy supply because they are used up quickly. Ideally, glucose for the brain should come from high fiber, slow releasing foods. Simple carbohydrates are like getting a onetime shot to stop pain. Complex carbohydrates, on the other hand, are like a slow release drug being released through an intravenous drip. Glucose is an important factor in learning and memory. Studies have indicated that when we have periods that involve mental concentration, we drain the hippocampus (which is a seahorse-shaped structure in the brain involved in learning and the formation of long term memories) 32 of glucose. Thus to maintain functioning of memory and learning, glucose must be supplied in this region of the brain. 3 3 The presence of glucose at normal levels is believed to improve one's memory and ability to learn. Glucose spikes are said to cause something similar to an "energy crisis"; these crises can cause an individual to become nervous and confused or feel weak and tired. Excess amounts of sugar can lead to glycation (reactions that causes glucose to react with proteins in the brain and nervous system, causing a slowdown in communication). Continuous drops can lead to a condition called hypoglycemia. When the brain is deprived of its main energy source, individuals process visual and auditory information at a much slower pace. The ability to concentrate is also affected when the brain's energy level are low or depleted.
The brain's cells consume about fifty percent more energy than any other cell in the body. They have such a high demand for energy because they are constantly undergoing biochemical processes. When we are asleep, our brain cells are still hard at work trying to maintain and fix structures that may be wearing out or may need restructuring. The brain cells are also responsible for making enzymes and neurotransmitters and getting these chemicals to their respective sites. The neurotransmitters alone can travel a few inches to several feet: energy is needed to keep this transport system working. The greatest user of energy by the brain cells comes from the processing of electrical signals that cause communication to occur in our nervous system. Half of the energy the cells receive goes to creating these "bioelectric "signals.
Breakfast and the Brain
Breakfast has been described as the most important meal for the brain. For maximum benefits, the meal should consist of high fiber low sugar meals with omega three foods such as eggs. Starting the day with foods that come from complex carbohydrates and essential fatty acids is believed to improve both cognitive and academic performance of students. Many studies have noted that attendance, as well as behavior, of students improves when a good wholesome breakfast is eaten. 34 Students who skip breakfast have difficulty with problem solving, short-term memory, and staying focused. Students who eat a breakfast high in fiber demonstrated improvements in the same skills. Eating a high fiber, low sugar breakfast affords the brain a long-term release of energy needed for the brain to function. Feeding the brain a good breakfast will make a positive difference in a student's day.
Fats and Our Mental, Emotional, and Physical IQ
Most people think about IQ from the standpoint of one's mental ability. However, there is also emotional IQ and physical IQ. Mental IQ might be defined as how well someone can reason and learn facts or new information. Emotional IQ is how appropriately we respond to the world around us and the types of relationships we develop with others. Physical IQ refers to our ability to coordinate and balance our bodies and use our senses in response to stimuli in our world. Diet is not normally associated with our mental, emotional and physical IQs. The brain influences mental abilities, and sets the stage for memory, attention, and learning all of which reference mental IQ. Research has identified that diets deficient in essential fats and high simple sugars can cause changes in mood and behavior which pertains to emotional IQ. Diets that restrict coordination and movement, or impact the senses are affecting physical IQ. A review of the nutrients the brain needs to function, indicate the impact they have on ones total well being. The three intelligences are what make people individuals.
Deficiencies in the fatty acids particularly DHA during gestation and after birth can cause children to have difficulty learning. Dietary deficiencies in polyunsaturated fatty acids are cited as a key reason for "mental impairments." Children with decreased levels of omega-3 fatty acids were found to experience more problems with their academic studies. These deficiencies in the fatty acids were also found to impact adult's cognitive skills and ability to learn also. Many studies that have demonstrated that fats and carbohydrates impact our lives on every level of intelligence. Therefore, for a healthy mind and body foods rich in the essential fatty acids and complex carbohydrates must be incorporated into our diets. Foods such as, cold water fish, variety of seafood, lean meats, a variety of fresh vegetables and fruits, whole grains, nuts and seeds. Elimination of trans fats and reduction of saturated fats and high sugar, low nutrient foods ensure that you are feeding your brain a good diet.
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