One need only look at the first several rows periodic table to find some elements essential to good mental health. Human brains need minerals to function normally, and a diet high in processed foods will lower mineral content, so that mineral levels in the body suffer. A recent paper reviews many minerals and how they influence mental health.
I have articles on Zinc and Magnesium already. These particular minerals play a major role in slowing down the fight or flight nervous system when stress gets out of hand. Unfortunately, stress itself causes us to waste these minerals (ask any ICU doctor who has had to give their patients magnesium by the bagful to keep the levels up). Therefore a diet low in minerals combined with a stressful lifestyle will leave us with more need for these minerals, even while we have an insufficient supply. Low zinc and magnesium are associated with depression and anxiety disorders and suicide, and studies in humans have shown that combining zinc with an antidepressant works better than an antidepressant alone in treating depression.
Another essential trace element with low intake levels associated with suicide, accidents, and violence is lithium. This element is found in mineral water and foods in small amounts, and it seems to help the brain be less reactive and recover better from stress. There are truckloads of data showing lithium to be effective in treating bipolar disorder and some forms of resistant depression, but the typical pharmacologic doses can have many side effects. Trace levels, say 2mg daily, such as one might find in the water supply of towns like El Paso, Texas, also seem to be protective against violence and suicide on a population level.
Iron is a mineral I haven’t explored in previous articles, but is also absolutely needed for good mental health. Low iron levels during pregnancy can lead to poor brain development and decreased IQ points in the offspring. Iron is needed in the proper activation and regulation of the NMDA receptor of the brain. Over or under activation of this receptor (yep, like Goldilocks, it has to be just right) is thought to lead to problems with anxiety, depression, psychosis, and even dementia. About 4 percent of men and 11 percent of women are iron deficient, particularly vegetarians, as red meat is a major dietary source. Children with severe and chronic iron deficiency can have major developmental problems with behavioral control and learning. Men with low serum ferritin (a measure of iron deficiency) have a higher chance of developing depression than men with normal ferritin levels.
Too much iron is also a problem; men and post menopausal women who are not anemic should donate blood regularly if possible, to keep iron levels from going too high. High ferritin is associated with high blood pressure and greater risk of death from cardiovascular events.
Chromium is a mineral that has previously been thought to help reduce insulin resistance, and some people take it as a weight loss aid. The evidence for its use in frank type II diabetes is poor, and there is little information on what the risks of long term supplementation might be. However, there is some data with respect to short term chromium supplementation and mental health in humans. The daily requirement is 20-25 micrograms in women and 30-35 micrograms in men, and dietary sources include broccoli, beef, eggs, liver, oysters, and chicken. Like iron, chromium helps the NMDA receptors work properly. In addition, it might affect the serotonin receptors in a positive way. There is a study of chromium picolinate causing antidepressant effects in atypical depression. A few other studies showed it helps premenstrual dysphoria and chronic depression.
Finally, calcium is another mineral we are very familiar with when it comes to health benefits, though we are used to thinking of it as essential for our bones. Like all minerals, too little is problematic, as is too much. High calcium supplementation with pills may be associated with problems with artery and valve calcification and greater risk of cardiovascular death (1) though the data is mixed (2). Calcium and magnesium tend to offset each other. In the brain, magnesium tends to decrease membrane activation, whereas calcium excites it. In the gut, calcium competes with magnesium for absorption. Excessive influx of calcium in the neurons is a likely cause of depression, manic episodes, migraines, and seizure disorders, though sufficient magnesium may protect against all of the above. Calcium channel blockers (normally used as blood pressure medications) also have some evidence to support their use in depression and anxiety. In general, intakes of dietary calcium via mineral water, greens, or dairy products seems to be safe, but we may need to revisit taking large amounts of calcium in pill form. To make strong bones, we need combinations of fat soluble vitamins such as vitamin D and K, as well as combinations of minerals such as calcium, zinc, and magnesium. Just mega-dosing with calcium could be similar to applying concrete powder to a foundation without the water and rebar to make for a strong base. What is good for the bones is likely good for the brain as well.
I recommend getting your minerals via liberal intake of mineral water, seafood, leafy greens, dairy (if you tolerate it) and a reasonable amount of red meat, chicken, and eggs. In some mental health conditions, judicious supplementation with zinc, magnesium, lithium, iron (for frank deficiency measured in a lab test), and chromium might be helpful, but it would be nice to have more long term data. These elements play vital roles in the regulation of the stress response and brain recovery and repair, and consideration of these elements are vital to a holistic understanding of mental health.