The recent news that chocolate stimulates the same brain receptors as marijuana is just the tip of the iceberg when it comes to examining how food influences cognition, mood, and behavior. Some of the mental-emotional effects of food are immediate, others are more gradual. What follows is not the complete story, but a few interesting examples. 

First of all, there is the consideration of the nutrient content of food. Deficiencies of just about any nutrient can have an adverse impact on mind and mood. As little as three days of nutritional supplementation has been shown to improve mood in violent criminals. How does this work? For example, docosahexaenoic acid (DHA), which is found in the diet in cold water fish, ideally should comprise about 18-24 percent of the dry weight of the brain and has been associated with improved mood and intelligence when present in the diet in adequate quantities. DHA has also been found to ease aggression during times of increasing mental stress. DHA and another dietary fatty acid called arachidonic acid have been found to be deficient in children with Attention Deficit Hyperactivity Disorder. Neurotransmitters, nervous system chemicals that are critical to normal functioning of mind, memory, and mood, are influenced by nutrient levels. Several B vitamins act as coenzymes driving chemical reactions that convert amino acids into neurotransmitters. Dietary carbohydrates stimulate insulin release, which helps spur the production of the calming neurotransmitter, serotonin. 

Another way food can influence mind and mood is by way of contaminants. Food additives, foreign chemicals, and heavy metals can all influence the nervous system. For example, lead, which sometimes contaminates water, inhibits release of neurotransmitters in the brain. The degree of toxicity of a single heavy metal is dependent upon the presence in the body of other heavy metals and deficiencies of various nutrients. Hair analysis has revealed patterns of heavy metal contamination in children with learning disorders and in adults with violent behavior. Mass murderers have been found to have a distinctive pattern of heavy metal contamination. Free radicals, which are highly destructive molecules resulting from heavy metals and other toxins, have been implicated in cell damage leading to Parkinson's and Alzheimer's Diseases as well. "Organic" produce, grown without synthetic chemicals, has been found to contain, on average, one-half the amount of toxic heavy metals and twice the level of nutrients of produce treated with pesticides and insecticides. 

Another important fact is that each individual's unique biochemistry allows for the possibility of atypical reactions to food. For example, in sensitive individuals, opioid peptides from gluten-containing grains are absorbed from the intestine, travel to the brain and cause symptoms of schizophrenia! Virtually any food has the potential to evoke a toxic response in any given individual, with the production of a variety of symptoms including mental-emotional ones. The way this may work is that an unusually large peptide (chain of amino acids) is absorbed into the blood intact from the intestines due to a combination of insufficient digestion and weakened intestinal barrier function. The peptide then comes in contact with the immune system (more than 50 percent of the immune system is clustered around the gastrointestinal tract), which recognizes it as a foreign invader to be destroyed. This activation of the immune system also involves the glial cells, which are immune cells located in the brain. 

To determine if a particular food is causing your mood swings, depression, impaired concentration, or any other symptom, eliminate it from your diet completely for 5 to 12 days, then reintroduce it and keep careful track of how your symptoms respond. The foods we consume most often are the ones most likely to cause an adverse reaction. Craving of the problem food is often present. 

The way we eat food can impact our mental-emotional state as well. Eating while in a tense state, not chewing food enough, drinking too much liquid with meals, and overeating, all compromise digestion. Maldigestion leads to diminished absorption of nutrients, increased absorption of excessively large food particles, and increased delivery of food to the colon where bacteria and yeast feed on it. Normally, food is absorbed from the small intestine into the bloodstream, but if it is not properly digested, it passes into the colon and becomes food for the trillions of bacteria and yeast that reside there. These organisms then multiply and their metabolic waste products are partially absorbed into the bloodstream. These waste products then circulate to the liver and are detoxified. The liver contains immune cells, which upon exposure to toxins release cytokines, chemicals that circulate through the body and activate other immune cells, including those in the brain. Additionally, if the liver's detoxification ability is overwhelmed, toxins travel throughout the body, impair function, and cause damage in all tissues, including the brain. Powerful evidence for this process is the finding of metabolic waste products of yeast in the urine of children with autism. 

Carbohydrate metabolism is a very important factor in mental-emotional functioning. Glucose is the brain's preferred fuel source. If glucose supply to the brain becomes impaired, a host of symptoms result. Of course, proper levels of blood sugar won't do any good if the circulation to the brain is compromised by atherosclerosis and so nutrition's effect on cardiovascular health needs to be considered as well. The body has a complex mechanism for keeping blood sugar levels properly regulated and it responds not only to the amount of sugar in the blood, but also to the rate of change in blood sugar. A part of the brain called the hypothalamus monitors blood sugar and is more sensitive than any man-made instrument. When blood sugar falls too rapidly or too low, the body responds with the secretion of several different hormones which then act to raise the blood sugar by converting glycogen (stored carbohydrate), protein and fat to glucose. The lining of the gastrointestinal tract is the main source for this protein. Breaking down of the intestinal lining can then contribute to the formation of food intolerance. One of the hormones involved in raising blood sugar levels is the adrenal hormone, Cortisol, which has varied and powerful effects on the body and mind. According to G. Fink at the Brain Metabolism Unit, University Department of Pharmacology in Edinburgh, England, "High levels of the glucocorticoid, cortisol, in blood ("hypercortisolaemia") remain the most robust biological correlate of the major psychoses, particularly depression and dementia, and are thought to potentiate neurodegeneration." What's my point? One of the causes of high levels of blood cortisol is dysglycemia - rapid swings in blood sugar. If your blood sugar often drops too low, you will develop elevated cortisol levels and be prone to, among other things, depression, dementia, and neurodegeneration! So what causes the blood sugar to drop too much? Fasting, delayed emptying of food from the stomach, maldigestion and malabsorption. The most common cause, however, is the body's overactive down-regulation of elevated blood sugar levels! The blood sugar climbs too high because of an excess of simple refined carbohydrates (such as sugar and white flour rich foods) being absorbed from the intestine into the bloodstream too rapidly. The body then responds with the secretion of insulin, which helps transport the glucose into the muscle and fat cells from the blood. The brain doesn't respond to insulin and so starves when insulin is over-secreted, a not uncommon occurrence when an excess of simple sugars are eaten. In children, the consumption of sugar has been found to increase the body's production of epinephrine or adrenaline. This can produce hyperactivity. 

Another hormone that responds to diet and has powerful effects on mind, mood, and memory is estrogen. Excessive and deficient levels of estrogen, seen in PMS and menopause respectively, are both problematic and can result in irritability, anxiety, depression, mood swings, forgetfulness, and confusion. The fact that excess estrogen can lower blood sugar levels, and cortisol can raise estrogen levels, illustrates the complex interrelationship of these body functions. As far as dietary influences on estrogen levels and activity, there are several considerations. The amount of estrogen in circulation is the result of an interplay between production and breakdown of the hormone in the body. B vitamins and magnesium are needed for the excretion of estrogen from the body and so deficiencies of these nutrients result in higher estrogen levels. PABA naturally decreases estrogen excretion. The breakdown of supplemental estrogen in the liver has been shown to be slowed by Naringenin, a compound in grapefruit juice. Estrogen levels are also influenced by the activity of certain bacteria residing in the intestines. When the body excretes estrogen into the intestines for elimination, it does so after binding it to a compound called glucoronide. Some species of bacteria in the intestines secrete enzymes, which break the bond between estrogen and glucoronide and this frees up the estrogen, allowing it to be reabsorbed into the bloodstream. The net effect is higher levels of estrogen in the blood. The activity of the involved bacteria is stimulated by dietary animal protein and fat and is lowered by dietary fiber, which is found in unprocessed plant foods. Fiber additionally aids in lowering estrogenic activity in the body by increasing levels of sex hormone binding globulin, which binds to estrogen in the blood and makes it inactive. Plants play another role in estrogen metabolism. Soy appears to be the richest source of compounds called isoflavones, which have weak hormonal effects in the body. These "phytoestrogens" help to normalize estrogen activity. If a woman has deficient levels of estrogen, soy can contribute to increased estrogen effects to some degree. If estrogen levels are too high, soy can help by competing with the body's own more powerful estrogens for binding to receptor sites. The net result is less estrogen activity. Soy also suppresses the production of estrogen by the body. One final factor to consider here is that our water and food supply is contaminated with a multitude of synthetic chemicals, many of which have estrogenic activity. Eating "organic" and free-range food, drinking filtered water, and supporting the body's detoxification pathways with proper nutrition is the solution to this problem.