Effects of Undernutrition and Malnutrition on Behavior by Dr. Chris Jackson, PhD, DOM

Malnutrition during fetal development often results in malnutrition as an infant and during later developmental stages, including adolescence and adulthood. A woman who is malnourished is likely to yield a malnourished child, possibly with diminished brain development, and generally, a failure to thrive. Failure to thrive, more common to poorer populations, may lead to decreased growth and a resulting lag in cognitive development that reduces achievement levels throughout life (Cole & Lanham, 2011). In a cyclical fashion, psychological conditions, such as depression, anxiety, obsessive-compulsive disorder (OCD), or anorexia nervosa, may also lead to malnutrition, further developing into additional psychological disorders, especially in the elderly (Clarke, Wahlqvist, Rassias, & Strauss, 1999; Cole & Lanham, 2011). Overnutrition, undernutrition or malnutrition may result in mineral or vitamin deficiencies or excesses. This result may be due to poor food choices, a lack of sufficient nutritious foods, malabsorption of the foods due to metabolic disorders, or the lack or excess of supplementation, all of which may be involved in the etiology of psychological disorders (Cole & Lanham, 2011).

Deficiency of the micronutrient element iodine is of broad importance. Iodine is an important component of thyroid hormone, thereby affecting hormone levels in the body and metabolism of all of the important nutrients. Iodine deficiency in early childhood may lead to measurably diminished intellectual abilities (lower IQ), partly due to an early role in brain development. Also, the deficiency may lead to thyroid dysfunction affecting nutrient and sugar metabolization, resulting in cognitive impairment. Additionally, iodine deficiency may be involved in the development of attention deficit hyperactivity disorder (ADHD) (Benton, 2008).

Deficiencies of minerals, particularly iron, zinc, selenium, magnesium, and copper may affect brain development, structure and function. Iron deficiency may result from excess zinc, reducing the number of neurons, thereby leading to memory problems and reduced ability to focus (Huss, Völp, & Stauss-Grabo, 2010). Magnesium and zinc deficiencies may also exacerbate the symptoms of attention deficit hyperactivity disorder (Huss et al., 2010). Deficient magnesium may decrease serotonin levels, reduce responsiveness to serotonin, reduce GABA levels, and affect the levels of stimulating neurotransmitters noradrenaline (norepinephrine) and dopamine, possibly leading to depression, anxiety, or sleep disorders (Lakhan & Vieira, 2008). According to Lakhan and Vieira (2008), excess vanadium may lead to bipolar disorder (BPD).

Vitamin deficiencies may also lead to psychological conditions. Vitamin A is important for neuron differentiation, and may be a key nutrient for proper memory function. Vitamin A deficiency is found to be more common in the poor and in the black population (Benton, 2008). Aside from excess vanadium, BPD may also evolve from deficiencies in B vitamins, specifically B12 or folate, or vitamin C. Vitamin C deficiency may contribute to excess vanadium, leading to BPD (Lakhan & Vieira, 2008). Deficiency of B12 can result in demyelination in early life and a lack of proper neurological development through adolescence, resulting in lagging cognitive development and depressive symptoms, possibly due to reduced methylation resulting in elevated homocysteine and reduced S-adenosyl-L-methionine (Black, 2008). However, the correlation between deficiencies of B vitamins and depression were not confirmed in a study by Kamphuis, Geerlings, Grobbee, and Kromhout (2008). According to Jorde, Sneve, Figenschau, Svartberg, and Waterloo (2008), depression can also result from deficient vitamin D levels. Additionally, McGrath (2010) suggests that schizophrenia may result from vitamin D deficiency (hypovitaminosis D), although this is not well-researched. Receptors for vitamin D are prominent in the brain, located particularly in the substantia nigra and hypothalamus, and functionally important to the hypothalamus-pituitary-adrenal (HPA) axis (Gracious, Finucane, Friedman-Campbell, Messing, & Parkhurst, 2012)..

Malnutrition or undernutrition may result in protein deficiency, leading to deficiencies of the amino acids, which may result in psychological disorders. According to Lakhan and Vieira (2008), deficiency of tryptophan can lead to serotonin deficiency, and tyrosine deficiency can lead to dopamine or noradrenaline (norepinephrine) deficiencies, possibly leading to depression, anxiety, or sleep disorders. Additionally, tryptophan deficiency, as well as deficiency of amino acid glycine, have been linked to schizophrenia. Deficiency of taurine can allow a build-up of excess acetylcholine. Interestingly, the excess acetylcholine may be helpful for Alzheimer's patients and those with memory issues, yet be harmful for individuals with BPD who may be sensitive to acetylcholine, leading to mania (Lakhan & Vieira, 2008).

Omega 3, 6, and 9 oils are important as well, especially to the development of the brain and neurological systems. In the case of deficiencies of omega 3 oil docosahexaenoic acid (DHA), a component of the cell membranes of neurons, aggressiveness may be elevated, and memory and learning may be negatively affected (Huss et al., 2010; Peet & Stokes, 2005). Deficiency of omega 3 oil eicosapentaenoic acid (EPA), a modulator of neuronal activity, may exacerbate the symptoms of schizophrenia. This inherent deficiency may be due to abnormal phospholipid metabolism, the lack of anti-inflammatory activity, or the lack of inhibition of phospholipase A2 in individuals with schizophrenia, and may also lead to depression or anxiety (Lakhan & Vieira, 2008; Peet & Stokes, 2005). Omega 3 and 6 deficiencies may also exacerbate the symptoms of BPD, postnatal depression, borderline personality disorder, and ADHD, including hyperactivity, impulsivity, sleep problems, emotional, and behavioral problems (Huss et al., 2010; Peet & Stokes, 2005).

As discussed, there are many nutritional deficiencies and some excesses that may be linked etiologically to psychological disorders, including OCD, BPD, schizophrenia, borderline personality disorder, depression, ADHD, anxiety, and others. Further study in all of these areas would be helpful in determining the full extent of causality and biologically required levels for treatment. Such research could help to advance the field of orthomolecular psychiatry and to reduce the widespread application of problematic antipsychotic drugs and their side-effects.

Nutrition and Behavior

A Path to Wellness