This article was originally presented to teachers at a Learning Brain conference.
It's 8:35. Your chalk is in hand and you're ready to start your day. You have carefully constructed a learning experience of visual input, hands-on activities, reading and experimentation - to help your students learn.
When you look around your room, do you see bright eyes and positive, expectant expressions, or do you see squirming, sleeping, or distracted students. What happens to your classroom mid-morning? Mid-afternoon? Do you have students who are stressed, depressed and anxious? According to experts, the internal environment of the brain is an integral part of learning, just as important as the classroom environment. You may find in some cases your students are not able to learn due to poor nutrition or inadequate hydration.
Within your student's brain, a biochemical process of learning is occurring, that parallels the classroom experience. Making connections, finding meaning, and solving problems are learning tasks that require lightning-fast electrical impulses between areas of the brain. Formation of memory requires physical growth and reshaping of networks of brain cells. So that wonderful experience - when the lights go on and your student says, "I get it!" - is a neurochemical process as well as an academic one. By nourishing the brain with healthy food and water, you will optimize the internal environment, enabling students to truly engage in the classroom environment and achieve their potential.
What does the brain need?
Place two fists together, with your inner wrists touching. Your brain is about this size and shape. In contrast to the rubbery pink models we have seen, the brain is amazingly soft, composed primarily of fat and water. It is grayish and pudding-like - composed of 100 billion brain cells - called neurons, that drive our thinking, learning, feeling and states of being. Neurons need good fats, protein, complex carbohydrates, micronutrients - vitamins, minerals and phytonutrients - and water. These nutrients are used to drive the learning functions of neurons.
Neurons are shaped somewhat like an outstretched hand, with fingers spread. Dendrites (fingers) receive information from other neurons, which is then sent through the axon (arm) to another neuron. The connection between two cells is called a synapse, where the dendrite of one cell nearly touches the body or axon of another cell. Neurons can connect multiple times with the same cell, grow extensions to connect with distant cells, and connect with many different cells at once by growing more dendrites. The brain is dynamic, responsive, and efficient: new connections will be made to record and integrate new information learned. Old, unused connections will be pruned away. This process of building and pruning is not confined to the time of the classroom experience, but continually evolves with all learning that occurs in a child's life, integrating what is learned within and outside the classroom, integrating life's experiences into the knowledge base and personality of the child. The raw material for building and pruning of these connections comes from the food we eat.
A biochemical language
As neurons connect, they communicate using a process called neurotransmission. As child thinks, speaks, moves or feels, electrical impulses triggers the release of messenger chemicals, called neurotransmitters (NTs), which travel across the synapse, transmitting information to the next cell. This cell-to-cell communication forms the basis of learning. NTs help connect verbal, emotional, visual and kinesthetic memories. They connect prior learning to new learning. NTs correlate with mood and behavior. They regulate learning states and levels of alertness. There are hundreds of these NTs, which are manufactured in the brain - all from food we eat.
Energy and Protection
Within the body of the neuron, corresponding to the palm of the hand in our analogy, is where the cell manufactures NTs, using protein, vitamins and minerals. Energy is generated from food, and regulates growth and change of cells. Neurons are prone to damage from environmental toxins that make their way into our systems, as well as toxic by-products formed in the body. The first line of defense? Antioxidants from food. Diets low in antioxidants have consistently been shown to cause and contribute to illness and disease. The brain, due to its high fat content, is especially vulnerable to damage and requires high levels of antioxidants for protection.
Just what should we feed the brain?
1 Good fats
In contrast to past years when fat was considered an unhealthy part of the diet, we now know that fats are essential. Of the solid matter in the brain, 60% is fat, since the brain consists largely of fatty membranes. Most brain fats are polyunsaturated, meaning their structure contains few or no double bonds, making the molecules flexible. These fats help maintain flexible, dynamic membranes that are able to transmit and receive information, and maintain other cell functions such as energy production, and water storage. Cholesterol, a saturated fat that is often linked with heart and vascular disease, is an important part of a healthy brain. Sufficient quantities of cholesterol are manufactured in the body without dietary sources. Fat provides energy for the brain as well, when it undergoes a transformation using B-vitmains and other trace nutrients within the neuron to produce pure ATP. The best fats to consume are omega-3 oils from fish, nuts, seeds and dark leafy greens. Omega 6 oils can be found in corn and safflower oils as well as borage oil.
What about trans fats? Saturated fats? Trans and saturated fats are not only a problem in themselves, but actually displace the good fats, creating stiff membranes instead of flexible ones. Stiff membranes impair subtle changes in shape that are essential for cell communication. Trans and saturated fats are like sludge in circulation system of the brain, impeding the flow of oxygen to the brain and the flow of wastes away from the brain. When these fats are present in a diet that is also low in magnesium, plaque formation and further damage can result. What will you see in the classroom? Trans fats accumulate especially in synapses, impacting all brain communication. They accumulate in the retina and can impact eye-brain coordination. Ann-Charlotte Granholm of the Medical University of South Carolina in Charleston, studied rats on a high trans-fat diet and found they developed learning difficulties. When the animals were required to remember the position of hidden platforms in a maze, the animals on the trans-fat diet learned more slowly and made more errors, especially with more difficult tasks. They performed about five times worse than those mice receiving soybean oil. Though this study evaluated mice, the findings mirror what has been observed in children. As you can see, a child eating mostly processed cakes and crackers, French fries and fried meats loaded with trans and saturated fats, will build a different brain than a child who is eating broiled fish, nut butter, salad dressings made with olive or safflower oil, eggs and lean meats.
Protein provides amino acids, building blocks that are used to form NTs and support structures in neurons. Tryptophan from turkey and milk is used to produce serotonin, an NT creating feelings of well-being. Tyrosine, an amino acid found in almonds, an avocado, bananas and meat, is used to make dopamine, associated with enthusiasm. Amino acids are also reassembled into powerful antioxidants that are used to protect DNA and other cell components from damage. Proteins also form receptors, structures embedded in membranes that aid in cell communication.
What are best sources? Protein comes in combination with other nutrients; it can be found in a healthy food or unhealthy food. For instance, nuts are a source of protein. Raw almonds have good fats, protein and well as an abundance of vitamins and minerals. On the other hand, roasted, flavored peanuts have had the beneficial oils removed, in fact overheating can cause damage to oils. Flavoring often consists of chemicals and dyes that cause behavioral reactions in some children and are helpful to no one. So, all nuts are not equal. A similar analysis could be made for chicken (baked vs. deep fried with batter) fish (coldwater broiled, providing good fats and protein vs. Batter fried, providing saturated and trans fats, excess calories) and yogurt (organic plain with fruit providing protein as well as beneficial bacteria for digestion, without hormones or pesticides vs. artificially colored, with sugar and candy sprinkles, providing sugar, additives, protein and little or no bacteria). The total value of the protein source is an important consideration.
Carbohydrates are an energy source for the brain. Sugar is the main fuel for the brain. Most of us have experienced the energy boost we get from eating something that provides sugar. However, most students consume excessive sugar, even for breakfast, causing bursts of energy followed by fidgeting, headaches, trouble concentrating, or drowsiness - often in mid-morning or mid-afternoon. As sugar levels rise in the bloodstream, the pancreas releases insulin, which directs sugar into cells, to keep blood sugar at a stable level. The more sugar eaten, the more insulin released, the drowsier the student. Many persons instinctively reach for more sugar to boost their energy, thus initiating this cycle again. Students who begin their day with a large donut and sugary juice drink, have a candy bar for a snack, followed by a pop in the afternoon. Imagine the effort it would take to overcome the rollercoaster effect of the sugar-insulin response - for the student and the teacher as well.
The solution? Meals and snacks should contain complex carbohydrates - i.e. whole grains or products made with whole grain flour, rather than refined sugars. Whole grain products contain not only complex sugars for energy, but fiber (a type of carbohydrate) which slows the rate of absorption of sugar, as well as B-vitamins, contained in the hull, and vitamin E and other nutrients, contained in the germ or center of the grain. Refined sugar lacks these additional nutrients, though sometimes certain vitamins are added back into the flour. Nonetheless, the absorption rate of refined sugar is generally higher, causing a greater release of insulin. The rate of conversion of a food to sugar is called the glycemic index (GI) - the higher the GI, the greater the insulin response. Though the drowsiness is enough of a reason to be concerned about the glycemic index of a food, a greater concern is that this type of diet stresses the pancreas, leading to impairment in the ability to manage glucose, the hallmark of type 2 diabetes, High GI foods have been shown to increase appetite and are major a contributor to obesity in children. impaired glucose control, along with obesity, and high fat diets, and sedentary lifestyle, are creating a generation of sick, aging youngsters.
Though micronutrients are needed in small amounts, they are absolutely necessary for brain health. Some key vitamins are the B-vitamin family, which aid in producing energy for brain cells, and help to manufacture key NTs like serotonin, which gives a sense of well-being, and GABA, which aids in focus and concentration. B-vitamins are found not only in the hull of grains but in leafy green vegetables as well. The mineral zinc is also involved in producing serotonin and GABA, as well as hundreds of other brain pathways. Zinc is essential to learning: it is used in the growth of dendrites, cell repair and pruning. It aids in synaptic adhesion - the process of "cementing" a new connection between neurons. In addition, zinc is essential in the formation of memory, and is found abundantly in the hippocampus, the area of the brain responsible for processing short-term and long-term memory. Where can you get zinc? Zinc is found in seeds and nuts, as well as red meat. Calcium is a mineral which is used to help maintain the electrical environment of the brain and also to regulate nerve transmission. It is used to help cleanse the brain by binding or displacing some harmful substances.
Another group of micronutrients, known as phytonutrients, are plant compounds that have tremendous health benefits for the brain. Phytonutrients impart color to fruits and vegetables and are the basis of the recommendation to "eat your colors.' Though they are not directly involved in producing NTs or building structures in the neuron, they are critical for repair and protection of neurons, acting as antioxidants that neutralize damaging free radicals, or protecting memory function. What's the best way to get vitamins, minerals and phytonutrients? A diet high in fruits and vegetables. The current recommendation of 5-9 servings a day is not being met with most children. According to the National Health and Nutrition Survey (NHANESIII) less than 15% of children are meeting this recommendation. This low -nutrient diet consumed by many of America's children certainly impacts the nutrient supply to the brain as well as overall health. Encouraging snacks of whole fruit and incorporating salads and cut-up vegetables from the color group, will provide a wide range of vitamins, minerals and phytonutrients.
One of the most fascinating aspects of neurons is that they store water in tiny balloon-like structures called vacuoles. Water is essential for optimal brain health and function. Water is necessary to maintain the tone of membranes for normal neurotransmission. It enhances circulation and aids in removing wastes. Water keeps the brain from overheating, which can cause cognitive decline and even damage. This is one of the main reasons to encourage students to drink water during exercise. Dehydration most commonly occurs because children go long periods of time without drinking water. When they are thirsty they often choose sweetened drinks instead of water. By the time thirst is felt, there may be a loss of body weight up to 2% from water loss, and a 10% cognitive decline may be present. Dehydration can lead to fatigue, dizziness, poor concentration and reduced cognitive abilities. Even mild levels of dehydration can impact school performance. It is interesting to note that hydration has been found to affect exercise tolerance. Students who are dehydrated tend to feel tired during exercise and avoid activity, a risk factor for obesity. When students are hydrated well before exercise and drink water during their exercise, they have a more enjoyable experience with less fatigue. Furthermore, children have a different response to exercise than adults, and tend to overheat more quickly, making good hydration essential.
Children in classrooms can be given structured water breaks or encouragement to keep a water bottle at their desks to sip throughout the day to achieve the recommended intake of 8 glasses a day, with 4 consumed during the school day.
Nutrition Makes a Difference
Nutrition and hydration are part of a foundation for healthy learning. Helping students make healthier choices is an essential part of their education and well-being. What can educators do to help create an optimal internal environment?
1. Have students keep a water bottle at their desk or take water breaks throughout the day.
2. Encourage students to bring only healthy treats - such as whole fruit, whole grain crackers, or veggies and dip, for birthday celebrations.
3. Teach children how to choose the healthiest foods from the menu that is available.
4. Be aware of your school's Wellness Policy and contribute or obtain support for change in your classroom/school.
5. Incorporate nutrition education into many areas of your curriculum.
By incorporating healthy food and water in the classroom experience, your students will be more attentive, and able to enjoy learning.