Food and Nutrients in Disease Management
Food and Nutrients in Disease Management
<b>I. INTRODUCTION</b>
Since amino acids obtained from dietary sources are the precursors of mood-regulating neurotransmitters such as serotonin and dopamine, amino acids are considered to hold potential in treating
depression. Neurotransmitter precursors are the subject of ongoing research.So why is this topic relevant to primary care medicine? Patients have taken matters into their own
hands. Patients are self-treating their depression with amino acid supplements and appear to be motivated by a perceived benefi t in their mood and overall health. The amino acid precursors tryptophan,
tyrosine, 5-hydroxytryptophan, and L-dopa are readily available as supplements at doses that exceed feasible dietary intake. Amino acids supplements have less potential for harm and larger therapeutic
effect when their use is physician-guided.This chapter presents the bundle damage theory of depression to probe the biologic basis of amino acid therapy. It offers primary care physicians a treatment protocol that implements laboratory testing to
guide dosing; explains the potential side effects and how these can be minimized; offers quality regulation in product selection; and presents a protocol for simultaneous use of medication and nutrients in
the treatment of clinical depression.
<b>II. EPIDEMIOLOGY</b>
Depression is a global problem. The World Health Organization notes:32 Nearly 5–10% of persons in a community at a given time are in need of help for depression. As much
as 8–20% of persons carry the risk of developing depression during their lifetime. The average age of the onset for major depression is between 20 and 40 years. Women have higher rates of depression than
men. Race or ethnicity does not infl uence the prevalence of depression. World wide depression is the fourth leading cause of disease burden, accounting for 4.4% of total Disability-Adjusted Life-Years
(DALYs) in the year 2000. It causes the largest amount of non-fatal burden. Disability from depression world wide is increasing. In 1990, the total years lived with disability (YLD) was 10.7%. By 2000, the
YLD had increased to 12.1% worldwide.33 Mental health conditions have a tendency to move upwards in ranking, while ranked as the fourth leading cause of disease burden in 2000, it is expected that
depression will move to second place by 2020, second only to heart disease.34 Population surveys suggest that while the incidence of depression is higher in the developed
countries of North America and Europe than in other regions, it is nonetheless a common condition throughout the world.38 The rate difference is often attributed to underdiagnosis, but newer data
suggest that the Western diet, stressful lifestyle, and higher toxicant exposures contribute to the prevailing high rates in Westernized countries.32
The monoamine theory fails to explain why the incidences of depression are increasing on a worldwide basis and is more prevalent in developed countries
<b>III. PATHOPHYSIOLOGY</b>
<b>The monoamine theory</b>
The monoamine theory of depression has long been the major framework against which the treatment of depression has been examined and developed due to the fact that the theory attempts to
provide a pathophysiologic explanation for depression and the actions of antidepressants. The central premise of the monoamine theory states that it may be possible to restore normal function in
depressed patients by targeting the catecholamine and/or serotonin systems with antidepressants.This theory is based on evidence that depression symptoms can be improved by administering
compounds that are capable of increasing monoamine concentrations in the nerve synapses. Early research focused on defi cits in the catecholamine system with specifi c emphasis on noradrenalin
as a potential cause for depression. With further research, the theory was expanded to include the serotonin system as a cause for depression. This research has led to the use of drugs for treatment of
depression that affect changes in monoamine uptake and enzymatic metabolism.1 While many of the depression treatments based on the monoamine theory appear to be initially
useful, many of them lack the short-term and long-term effi cacy needed for relief of symptoms in most patients. In several studies of reuptake inhibitors administered, only 8% to 13% of subjects
obtained relief of symptoms greater than placebo. Remission rates for escitalopram compared to placebo in adults was studied (48.7% vs. 37.6%, P = 0.003). Here, 11.1% of subjects obtained relief
greater than placebo.35 Remission rates for citalopram versus placebo in another study were studied (52.8% vs. 43.5%, P = 0.003). Here, 9.4% of patients obtained relief greater than placebo.35
Venlafaxine-XR was similar to