Lithium (Li) is a trace mineral, used in the treatment of bipolar disorder at doses hundreds of times higher than that from diet. The main dietary sources are vegetables and grains, followed by dairy. The concentration in water varies widely: @evolutionarypsy recently tweeted San Pellegrino's high Li content of 200mcg/L.
Among myriad actions it decreases brain inflammation by reducing brain arachadonic acid levels and increasing the concentration of an anti-inflammatory metabolite of DHA (evolutionarypsychiatry.com/2010/07/lithium-and-inflammation.html). It also supports B12 and folate transport into cells.
In Japan and Texas there's an inverse correlation between tap water's lithium concentration and suicide, and the Texas study also showed lower arrests for drug use and violent crime.
In the Japanese study the highest concentration in water was 59mcg/L.
400mcg Li improved mood in a small placebo-controlled trial in former drug users. "In the Li group, the total (positive) mood test scores increased steadily during the four weeks of supplementation and specifically in the subcategories reflecting happiness, friendliness and energy. In the placebo group, the combined mood scores showed no consistent changes; the happiness scores actually declined." http://www.jacn.org/content/21/1/14.long
Drinking mineral water relatively high in Li increased BDNF (the hallowed brain-derived neurotrophic factor also increased by things like exercise and eating your blueberries), and reduced anxiety scores (in a non-controlled trial) www.gjpsy.uni-goettingen.de/gjp-article-shiotsuki.pdf
And it may affect lifespan - http://www.ncbi.nlm.nih.gov/pubmed/21301855
Does avoiding grains and dairy make the Li content of your water more important? Should San Pellegrino join Kerrygold in the hall of fame?
Anyone aware of Li levels in water in Africa, or estimates of paleolithic Li intake?
Not another thing to tweak, you neurotic OP! (?)
-- edit: A psychiatrist recently drew flack in Ireland for suggesting more lithium in tap water, which resulted in inevitable comments about medicating the populace, and comparisons with Brave New World. If we have higher rates of mental health problems in low lithium areas it makes me wonder about the norm in the evolutionary "milieu". On the other hand just as depression isn't an antidepressant deficiency maybe protective effects of small quantities of lithium are more "medicinal" than normal physiology at work. http://www.irishexaminer.com/ireland/kfqlojsnmhcw/rss2/