Eating patterns are important to mental performance and a change can affect overall nutrient intake. During periods of stress, some people will eat less, some may eat more, and others may turn to alcohol or subsist on coffee. No two individuals will react the same. Each scenario can cause an imbalance of neurotransmitters resulting in a mind and body that looks, feels, and reacts poorly.

To Eat or Not to Eat.

Individuals who cope with stress by consuming fewer calories may have their ability to think clouded. One study conducted at the AFRC Institute of Food Research in Reading, England showed that dieters who cut their calories by more than one thousand per day scored worse on a mental aptitude test compared to non-dieters. Short-term memory and the ability to quickly process information were impaired and these abilities continued to deteriorate the longer the people stayed on the diet.

Timing of meals is also important.

If you are having trouble concentrating, staying motivated, or just thinking clearly, your breakfast, or lack thereof, could be the culprit. The brain depends entirely on glucose to fuel its activity. Frequent skipping of meals will exhaust glucose reserves, leaving your brain with an energy deficit. Studies with children show that eating breakfast improves school attendance, reduces illnesses, increases motivation and interest in learning, and elevates mood. Adults also perform better at work if they have eaten a nutrient-packed breakfast.

Eating too much food can also impair brain function.

Overeating can cause drowsiness by impeding nutrient transport into the brain. It appears that high blood fat levels increases blood thickness, which decreases the transport of oxygen to brain cells.

What you eat also determines your brain power.

Although carbohydrate-rich foods at breakfast will help fuel, you’re thinking during the morning hours, they may make you sleepy and less able to concentrate after lunch. Bonnie Spring, Ph.D., from Harvard University reports that mental alertness and the ability to concentrate may decrease after a midday meal of carbohydrate-rich foods. This effect is compounded if the primary source of the carbohydrates is simple sugars. Research indicates that high fat and “heavy” meals (more than 1,000 calories) have a similar effect. In contrast, a light midday meal that supplies approximately 500 calories in a mixture of protein and carbohydrates will fuel the body without making you groggy.

Just do not forget the most essential nutrient: water.

Approximately 50 to 70 percent of the body is water. Every cell, tissue, and organ, requires water to function. Just a little lack of water cause tiredness and weakness. Adults need to drink at least 1.5 liters of fluid daily, even more if it is hot or they are physically active.

Vitamins and Minerals

Vitamins and minerals have direct effects on brain function, thinking ability, and memory. Compounds including magnesium, iron, the antioxidants (beta-carotene, vitamin C, and vitamin E), the B vitamins, and choline play vital roles in maximizing mental prowess. Americans are eating more calories than ever before. Yet, it is ironic that in the land of plenty we may be under nourishing our brains. The sad truth is that three out of every five calories are from sugar or fat, which leaves very little room for nutrient dense foods.


Thiamin is a B vitamin found in enriched grain products, pork, legumes, nuts, seeds, and organ meats. Thiamin is intricately involved with metabolizing glucose, or blood sugar, in the body. Glucose is the brain's primary energy source. Thiamin is also needed to make several neurotransmitters.

Vitamin B-12

Vitamin B-12 is found only in foods of animal origin like milk, meat, or eggs. 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.

Vitamin B-12 is needed to maintain the outer coating, called the myelin sheath, on nerve cells. Inadequate myelin results in nerve damage and impaired brain function. Vitamin B-12 deficiency can go undetected in individuals for years, but it eventually causes low blood iron, irreversible nerve damage, dementia, and brain atrophy.

Folic Acid

Folic acid is another B vitamin found in foods such as liver, yeast, asparagus, fried beans and peas, wheat, broccoli, and some nuts. Many grain products are also fortified with folic acid. In the United States, alcoholism is a common cause of folic acid deficiency.

Folic acid is involved in protein metabolism in the body and in the metabolism of some amino acids, particularly the amino acid methionine. When folic acid levels in the body are low, methionine cannot be metabolized properly and levels of another chemical, homocysteine, build up in the blood. High blood homocysteine levels increase risk of heart disease and stroke.
Even modest folic acid deficiency in women causes an increased risk of neural tube defects, such as spina bifida, in developing fetuses. Folic acid deficiency also increases risk of stroke. Some studies suggest that folic acid deficiency leads to a range of mental disorders, including depression, but this concept remains controversial. Folic acid deficiency can lower levels of serotonin in the brain.


The B vitamin niacin is found in enriched grains, meat, fish, wheat bran, asparagus, and peanuts. The body can also make niacin from the essential amino acid tryptophan, which is found in high-quality animal protein foods like meat and milk. Niacin deficiency used to be common in the southern United States but is now common only in developing countries such as India and China.

Niacin 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. Severe niacin deficiency progresses to a condition called pellagra, which is characterized by the four D's: dermatitis (a rash resembling a sunburn), diarrhea, dementia, and ultimately, death. The mental symptoms in pellagra can progress to psychosis, delirium, coma, and death.

Vitamin B-6

Vitamin B-6, also known as pyridoxine, is found in many plant and animal foods, including chicken, fish, pork, whole wheat products, brown rice, and some fruits and vegetables. In healthy individuals, deficiency of vitamin B-6 is rare, but certain drugs, including some antidepressant drugs, can induce vitamin B-6 deficiency. Vitamin B-6 is needed by the body to produce most of the brain's neurotransmitters. It is also involved in hormone production. Although rare, vitamin B-6 deficiency is characterized by mental changes such as fatigue, nervousness, irritability, depression, insomnia, dizziness, and nerve changes. These mental changes are related to the body's decreased ability to manufacture neurotransmitters with vitamin B-6 deficiency.

Just as vitamin B-6 deficiency causes mental changes, so does excess of vitamin B-6. Vitamin B-6 supplements are used by many individuals for a variety of conditions, including carpal tunnel syndrome, premenstrual syndrome, and fibrocystic breast disease. Doses of 500 mg per day or more can cause nerve damage, dizziness, sensory loss, and numbness.

Vitamin E

Vitamin E is a fat-soluble vitamin that is plentiful in the diet, particularly in plant oils, green leafy vegetables, and fortified breakfast cereals. Vitamin E deficiency is very rare, except in disorders that impair absorption of fat-soluble vitamins into the body, such as cystic fibrosis, and liver diseases.

Vitamin E deficiency causes changes in red blood cells and nerve tissues. It progresses to dizziness, vision changes, muscle weakness, and sensory changes. If left untreated, the nerve damage from vitamin E deficiency can be irreversible. Because it is an antioxidant, vitamin E has also been studied for treatment of neurological conditions such as Parkinson's and Alzheimer's disease. Although results are inconclusive, vitamin E shows some promise in slowing the progression of Parkinson's disease.

Vitamin A

Vitamin A is a fat-soluble vitamin found in meats, fish and eggs. A form of vitamin A, beta-carotene, is found in orange and green leafy vegetables such as carrots, yellow squash, and spinach. Headache and increased pressure in the head is associated with both deficient and excess vitamin A intake. Among other effects, excess vitamin A intake can cause fatigue, irritability, and loss of appetite. Generally, doses must exceed 25,000 international units of vitamin A over several months to develop such symptoms.

Not only does stress affect nutrient intake, but specific vitamins and minerals are jeopardized. Heightened stress hormones may increase excretion of minerals such as chromium, copper, magnesium, iron, and zinc. During one study conducted by the U.S. Department of Agriculture, participants who went through “Hell Week” (extra work, difficult deadlines) had blood levels of several minerals drop by as much as 33 percent.


Magnesium appears to be particularly sensitive to stress. During stressful periods, cellular magnesium decreases and urinary loss of magnesium increases. If the losses are not replaced, a deficiency can occur. Even a marginal magnesium deficiency can raise stress-hormone levels and cause stress-related depression and irritability. Illustrating this connection are human studies that show Type a personalities have higher blood levels of stress hormones and lower magnesium levels than their more relaxed Type B counterparts.

Magnesium is found in green leafy vegetables, whole grains, nuts, seeds, and bananas. In areas with hard water, the water may provide a significant amount of magnesium.


Iron deficiency is the most common nutrient deficiency in the United States and it is estimated that as many as 80 percent of active women have low iron in their tissues. Iron deficiency during the first two years of life can lead to permanent brain damage. Iron impacts on brain functioning in two ways. First, iron is needed for hemoglobin (the red pigment in blood) to work properly and carry oxygen to all the body's cells, including the brain. One of the first signs of low iron intake is tiredness and fatigue. Second, iron works directly with neurotransmitters and proteins including dopamine. This not only affects energy level but can also adversely affect job performance and even IQ. One study showed that as blood levels of iron increased, nerve activity in the left hemisphere of the brain (the region responsible for analytical thought) also increased. Consuming a food rich in vitamin C, such as orange juice, at the same time as an iron-containing plant food will enhance iron absorption from the food.


The richest sources of the trace mineral copper in the diet are organ meats, seafood, nuts, seeds, whole grain breads and cereals, and chocolate. In addition to other functions, copper is involved in iron metabolism in the body and in brain function. Deficiency of copper causes anemia, with inadequate oxygen delivery to the brain and other organs. Copper deficiency also impairs brain functioning and immune system response, including changes in certain chemical receptors in the brain and lowered levels of neurotransmitters.


The trace mineral zinc is found in red meats, liver, eggs, dairy products, vegetables, and some seafoods. Among other functions, zinc is involved in maintaining cell membranes and protecting cells from damage. Zinc deficiency can cause neurological impairment, influencing appetite, taste, smell, and vision. It has also been associated with apathy, irritability, jitteriness, and fatigue.


Antioxidants are those substances which act in the body to disarm free radicals before they can do damage. Free radicals are highly reactive particles that are found in the environment but are also produced in the body during normal metabolic processes. Free radicals damage the body’s cells and are implicated in the aging process. Fortunately, the body has an antioxidant system of vitamins, minerals, and enzymes to minimize the impact of free radicals.

The primary antioxidant nutrients are beta-carotene, vitamin C, vitamin E and selenium. Beta carotene prevents the formation of free radicals and vitamin E deactivates free radicals before they damage fat molecules in the nerve cells. Considering the fact that the brain is almost 60 percent fat, sub-optimal levels of vitamin E and beta-carotene could have far-reaching effects on brain cell structure and function as well as mental ability. Vitamin C not only functions as a free radical scavenger but also aids in the manufacture of nerve chemicals. Studies show that laboratory animals on a diet high in vitamin C and antioxidants lived longer than those on a diet low in vitamin C.

Author's Bio: 

Michelle L. Taylor is the Wellness Program Director at Monarch Health Promotions in Tucson, Arizona and one of the Wellness Experts at

Please feel free to contact her on the web at or by phone at (520) 404-4558.