Nutrition and mental health
A person’s mood, behavior, and brain function are affected by the food he/she takes. Mental health can be influenced by several factors including: intake of energy, nutrients (proteins, carbohydrates, and fats), alcohol intake, and intake of vitamins and minerals.
Our brain has specific energy and nutrient needs. Changes in food intake can alter brain chemistry and functioning of the mind. Food intake affect levels of chemicals in the brain called neurotransmitters, which transmit impulses from one brain cell to another. Neurotransmitters influence thinking, mood, and sleep patterns. Deficiencies or excesses of certain vitamins or minerals can cause disorder in the functioning of brain cells, causing difficulty in memory, and problem-solving ability, changes in mood, and impairing function of the mind.
Energy, (calorie content) is derived from the carbohydrate, protein, fat, and alcohol found in foods and beverages. People who do not have adequate intake of calories will experience changes in mental functioning. Skipping breakfast can result in lower fluency of thinking and problem-solving ability. The body responds to chronic energy deprivation by slowing down functions, altering activity levels, hormonal levels, oxygen and transport of nutrients, the body’s ability to fight infection, and many other bodily functions that directly or indirectly affect brain function. A hungry person may also experience lack of energy or motivation, irritability, and restlessness. A person who does not get adequate nutrition over a period of time may be apathetic, sad, or feel hopeless. Developing fetuses and young infants are particularly susceptible to brain damage from malnutrition. Malnutrition early in life has been associated with below-normal intelligence, and functional and cognitive defects.
Carbohydrates, including starches, sugars, and dietary fiber, significantly affect mood and behavior. Foods rich in carbohydrates, such as breads, rice, pasta and cereals, whole-grain products, fruits and vegetables, trigger release of the hormone, insulin, in the body. Insulin helps let blood sugar into cells where it can be used for energy, but insulin also has other effects in the body. Tryptophan, an amino acid, or a building block of protein, affects levels of neurotransmitters in the brain. It is used to produce the neurotransmitter Serotonin, in the body. As insulin levels rise, more tryptophan enters the brain, more of the neurotransmitter serotonin is produced. Higher serotonin levels in the brain enhance mood and have a sedating effect, promoting sleepiness. This effect is partly responsible for the drowsiness some people experience after a large meal.
Proteins are made up of amino acids linked together in various sequences and amounts. The human body can manufacture some of the amino acids, but there are eight essential amino acids that must be supplied in the diet. A complete or high-quality protein contains all eight of the essential amino acids in the amounts needed by the body. Many of the neurotransmitters in the brain are made from amino acids. Dopamine is made from the amino acid tyrosine. Serotonin is made from the amino acid tryptophan. Foods rich in protein include meats, milk and other dairy products, and eggs. Dried beans and peas, grains, and nuts and seeds also contain protein, although the protein in these plant foods may be low in one or more essential amino acid. Generally, combining any two types of plant protein foods together will yield a complete, high-quality protein. A diet deficient in the needed amino acid results in decreased levels of that particular neurotransmitter in the brain thereby affecting mind functioning and mood. Low brain levels of serotonin are associated with low mood and even aggression in some individuals.
Dietary fats found in both animal and plant foods, meats, regular-fat dairy products, butter, margarine, and plant oils have been linked to brain functioning and deficiencies in these may cause depression. Reducing fat and cholesterol in the diet (to prevent cardiac disorders) may deplete brain serotonin levels, causing mood changes, anger, and aggressive behavior.
Alcoholic beverages provide energy but virtually no vitamins or minerals. Alcoholism is one of the most common causes of nutritional deficiencies. Extra amounts of certain vitamins, such as Thiamine, are needed to break down alcohol in the body, further contributing to nutrient deficiencies. Contrary to popular belief a high alcohol intake can interfere with normal sleep patterns, and affect mood and functioning of the mind.
Vitamin B-12 found in foods of animal origin like milk, meat, or eggs, is needed to maintain the outer coating, called the myelin sheath, on nerve cells. Inadequate myelin results in nerve damage and impaired brain function. Strict vegans who consume no animal-based foods need to supplement their diet with vitamin B-12 to meet the body’s need for this nutrient. Chronic vitamin B-12 deficiency can cause irreversible nerve damage, dementia , and brain atrophy.
Folic acid, found in liver, yeast, asparagus, fried beans and peas, wheat, broccoli, and some nuts, is involved in protein metabolism in the body and in the metabolism of some amino acids, particularly the amino acid methionine. Low folic acid levels result in methionine not being metabolized properly. This can cause levels of another chemical, homocysteine, building up in the blood. Folic acid deficiency can lower levels of serotonin in the brain. All these can lead to a range of mental disorders, including depression.
Niacin, found in enriched grains, meat, fish, wheat bran, asparagus, and peanuts, is involved in releasing energy in the body from carbohydrates, proteins, and fats. A deficiency of niacin produces many mental symptoms such as irritability, headaches, loss of memory, inability to sleep, and emotional instability.
Vitamin B-6, (Pyridoxine), found in many plant and animal foods, including chicken, fish, pork, whole wheat products, brown rice, and some fruits and vegetables, is needed by the body to produce most of the brain’s neurotransmitters. It is also involved in hormone production. Vitamin B-6 deficiency can result in mental changes such as fatigue, nervousness, irritability, depression, insomnia, dizziness, and nerve changes.
Vitamin A, is found in meats, fish and eggs, and in orange and green leafy vegetables such as carrots, yellow squash, and spinach. Excess of Vit A can cause headache, fatigue, irritability, and loss of appetite.
Magnesium, found in green leafy vegetables, whole grains, nuts, seeds, and bananas, and hard water, aids in the transmission of nerve impulses. Deficiency of Magnesium can cause restlessness, nervousness, and apathy.