Lecithin is a fatty substance found in every cell in your body. One of the substances found in lecithin, choline, is used to synthesize acetylcholine, a neurotransmitter that plays a vital role in learning and memory. Because lecithin can be used as a precursor to a neurotransmitter, there has been some interest in its possible antidepressant properties.
Acetylcholine Synthesis
Research on both rats and mice indicates that supplementing the diet with choline may increase the synthesis of acetylcholine in the brain. Mice injected with choline have been shown to retain new information better, according to a 2001 article in "Neuroscience." Furthermore, the dietary restriction of choline has the opposite effect and inhibits acetylcholine release, according to a December 2001 article in "Brain Research Bulletin."
Acetylcholine and Depression: Animal Research
An April 2011 article in "Neuropsychopharmacology" reports that behavioral depression in rats is correlated with the action of acetylcholine in the nucleus accumbens. When they were given Prozac, the rats showed less behavioral depression and had lower levels of acetylcholine in the nucleus accumbens. These results suggest that antidepressants work, in part, by decreasing the activity of this neurotransmitter, and that higher levels of acetylcholine may be correlated with increased, rather than decreased, levels of depression.
Smoking and Depression
You may have noticed that people suffering from major depressive disorder are more likely to smoke than are non-depressed people, apparently because nicotine, which acts on the cholinergic system, lessens their discomfort.
Until recently, it was thought that nicotine was activating acetylcholine receptors. Recent research published in the December 2010 issue of "Trends in Pharmacological Sciences," however, suggests that nicotine has the opposite effect by blocking those receptors, rendering them less active. If this is the case, depression might by eased by reducing acetylcholine signaling rather than enhancing it through lecithin supplementation.
Choline and Anxiety
A 2009 article in "The American Journal of Clinical Nutrition" assessed the effects of dietary choline on depression and anxiety. While choline intake had no effect on depression, it did have a positive effect on anxiety. People whose choline intake was in the bottom 20 percent were significantly more likely to suffer from anxiety than people with higher levels of this nutrient, suggesting that lecithin might be beneficial to people suffering from anxiety, even if it has no effect on depression.
References
- Vanderbilt University; Lecithin Supplement's Effectiness in Weight Loss; Christine Lawhon;
- "Neuroscience"'; Glucose Plus Choline Improve Passive Avoidance Behaviour and Increase Hippocampal Acetylcholine Release in Mice; S.R. Kopf, et al.; March 14, 2001
- "Brain Research Bulletin"; Dietary Restriction of Choline Reduces Hippocampal Acetylcholine Release in Rats: In Vivo Microdialysis Study; A. Nakamura, et al.; December 2001
- "Neuropsychopharmacology"; Fluoxetine Alleviates Behavioral Depression while Decreasing Acetylcholine Release in the Nucleus Accumbens Shell; D.T. Chau, et al.; April 27, 2011
- "Trends in Pharmacological Sciences"; Nicotine Receptors and Depression: Revisiting and Revising the Cholinergic Hypothesis; Y. S. Mineur, et al.; December 2010
- "American Journal of Clinical Nutrition"; Choline in Anxiety and Depression: the Hordaland Health Study; I. Bjelland, et al.; October 2009
