The relationship between food and mood has intrigued people for ages. Three thousand years ago the Aryuvedic sages of India described how the body's natural rhythms were affected by the time of the day, seasonal changes, and diet.

They observed that morning is the time of clearest thinking, whereas midafternoon is the time of irritability and fatigue. Current research is again examining the connection between the mind and the body, attempting to explain what the ancients observed: that what and when we eat can alter brain chemistry.

The Role Your Brain Plays

Theories about how food affects behavior revolve around chemicals called neurotransmitters, biochemical messengers of the brain that pass information from cell to cell. They exert control over many of the body's functions, including the regulation of mood and appetite, thoughts, feelings and behaviors. The neurotransmitters that are most sensitive to diet and influential in affecting mood are serotonin, norepinephrine and dopamine.

Serotonin is the neurotransmitter responsible for feelings of optimism, relaxation, general sense of well being, and the ability to focus and concentrate. However, depending on the time of day, high levels of serotonin can make you feel tired and sluggish. Low levels of serotonin result in depressed mood, difficulty sleeping, poor concentration, and increased food cravings.

Dopamine and norepinephrine are responsible for feelings of alertness, excitement, action and mental acuity. Low levels of these neurotransmitters result in depressed mood, fatigue, and poor concentration, whereas high levels can create agitation and anxiety.

The Connection Between Food and Mood

The brain synthesizes these neurotransmitters from amino acids, the "building blocks" of protein. There are two amino acids that play a part in the food/mood response: tryptophan and tyrosine. Tryptophan is converted into serotonin, whereas tyrosine is the principal ingredient in dopamine and norepinephrine.

To increase the level of tyrosine in your brain, simply eat foods high in protein (meat, milk products, fish, beans, nuts, soy products). Tyrosine will be converted into dopamine and norepinephrine. With only 3-4 ounces of protein, you will feel energized, more alert and more assertive.

To boost the production of serotonin, reach for carbohydrate rich foods (pasta, starchy vegetables, potatoes, cereals, breads). Carbohydrates enhance the absorption of tryptophan, which is converted into serotonin in the brain. Within about thirty minutes of eating a carbohydrate snack, you will feel more calm and relaxed. The effects will last several hours.

Despite the fact that serotonin is manufactured in the brain from tryptophan, found in protein-rich foods, a meal rich in protein actually lowers the blood level of tryptophan. Even a modest amount of protein will counteract the calming effects of carbohydrates. Here's why. Protein-rich foods contain a variety of amino acids, including tryptophan and tyrosine, all competing with each other to get past the "Blood Brain Barrier", the gateway to the brain.

When you eat protein, you flood the system with these competing amino acids and they fight for entry. Tryptophan is a large amino acid; only a small amount actually makes it through. Consequently, the serotonin level does not increase very much. As a result, you may reach for a high carbohydrate dessert, feel more down, or not sleep well that night.

Conversely, a carbohydrate meal will result in fewer competing amino acids. A meal rich in carbohydrates triggers the pancreas to release insulin. Insulin directs most amino acids in the blood stream to be absorbed into the cells of the body. Tryptophan, which remains in the blood stream, then has an easy entry into the brain. Serotonin levels increase resulting in a more relaxed, focused mood.

All carbohydrates are not equal in their ability to offer mood-altering results. The best way to consume carbohydrates is in the form of whole grains and complex carbohydrates. Whole grains are broken down over long period of time, keeping a constant flow of serotonin in our body. Remember, to experience the maximum effect of carbohydrates on your mood, it is important to eat them alone. An English muffin with jam is fine, with tuna fish or melted cheese isn't.

Eating any of the following grains will help you feel more focused and relaxed: bread, pasta, potatoes, rice, corn, barley, kasha, and oatmeal. Fruits and leafy green vegetables are vitamin rich and important for a well balanced diet, however they are "mood-food neutral".

Snack foods to help you concentrate better and ward off tension in the middle of the day include popcorn, pretzels, baked potato (hold the butter and sour cream), and rice cakes.