The Gut-Brain Connection to Anxiety.
Over the past few years there has been mounting evidence that bacteria in the gut can play a huge role in our overall mental health. Harmful bacteria is known to ramp up anxiety and several studies have shown that probiotics can have the opposite effect. It’s a two-way street, says Dr. Siri Carpenter, writing for the American Psychological Association, just as bacteria in the gut seem able to influence the brain, so the brain can exert influence on the gut. Stress, for example, manages to suppress beneficial bacteria and opens the way for harmful bacteria to flourish causing inflammation and increased risk of infection. Some experts are now suggesting that people suffering from anxiety may benefit from eating more healthy bacteria in order to correct the imbalance that has accumulated in the gut.
The average adult carries around five pounds of bacteria in the gut and the effects of correcting bacterial imbalance can be dramatic according to a study published in Nutritional Neuroscience. In an interview with ABC news, Dr. James Greenblatt, a Boston-area psychiatrist, described how a simple urine test revealed elevated levels of HPHPA (a chemical byproduct of clostridia bacteria) in a teenager with obsessive-compulsive disorder and attention deficit hyperactivity disorder. He put the patient on an intensive dose of probiotics and after six months the symptoms began to disappear. Greenblatt says he now checks everyone in the same way and while “eight out of ten are fine, in the two patients where it’s elevated, it can have profound effects on the nervous system.”
Such findings appear to offer a tantalizing treatment but research into the gut-brain connection is still in its infancy. Certainly for a subset of people with anxiety or possibly even depression there may be relatively quick and useful outcomes by changing diet, but it’s by no means a magic bullet. Everyone has their own unique system determined in part by genetics and in part by the bacteria that live in on and around us. Gut bacteria actually produce hundreds of neurochemicals that the brain then uses to regulate psychological processes like learning, memory and mood. Did you know, for example, that gut bacteria manufacture about 95 percent of the body’s supply of serotonin?
Much of the research to date has been with animal studies and it looks like we’re many years away from a time when doctors may routinely check our gut bacteria when we report symptoms of anxiety or depression. Even so there are increasing indications that healthy bacteria can reduce stress-induced hormones while increasing the expression of receptors for the neurotransmitter GABA, which helps to calm us.
The copper/zinc ratio connection to anxiety exploredA study titled "Decreased zinc and increased copper in individuals with anxiety" was conducted at the Research Institute, Pfeiffer Treatment Center of Warrenville, Illinois, and published by Nutrition and Metabolic Insights in 2011.  [2a]
Highly advanced and expensive Inductively Coupled Plasma-mass Spectrometry (ICP) was used to measure trace minerals in the serum of 38 individuals with chronic anxiety and 16 in a control group without anxiety symptoms.
The researchers discovered that the anxiety group had generally lower serum zinc levels compared to copper or elevated copper compared to zinc. They were treated with zinc and antioxidant supplements, according to individual parameters, and their symptoms improved significantly.
Copper piping for water in dwellings has become the norm, and that does contribute to ingesting traces of copper beyond most diets. But raising zinc levels is a more functional factor than lowering copper levels.
Functional medicine practitioner  and acupuncturist Chris Kresser elucidates this topic further by explaining it's the ratio of copper to zinc (Cu/Zn) that determines neurotransmitter health or dysfunction. Ideally, your copper blood level should be 70% of your zinc level, or Cu/Zn at .7/1.
Not everyone has access to ICP technology for measuring trace mineral testing, so Kresser recommends the 24 hour urine sample test, which can be more accurate than most blood tests. 
Kresser explains that copper and zinc are involved with neurotransmitter health, but zinc needs to dominate. If not, all sorts of neurological disorders can emerge, including depression, anxiety and even schizophrenia. 
Copper and zinc tend to be antagonistic to each other. Excess copper can also invite Wilson's Syndrome, first identified by Dr. Denis Wilson, which resembles hypothyroidism and is characterized by low baseline body temperatures and possibly low level depression.
Orthodox medical institutions reject this as a valid medical diagnoses, which doesn't make it less real. With this particular syndrome, the 24 hour urine test is required over any blood testing, according to Chris Kessler, to determine if excess copper is responsible.
Of course, there are inexpensive zinc supplements available. Food sources for zinc include pumpkin seeds, Brazil nuts, broccoli, legumes and whole grains such as brown rice. Grains and legumes also contain phytic acid that binds to zinc and blocks absorption. 
So it's a good idea to soak brown rice and beans overnight in fluoride free purified water to reduce the phytic acid and free up the zinc (http://www.naturalnews.com).
Unfortunately, chocolate and cacao are high in copper. But the recommended focus is to boost zinc instead of reducing copper. Since zinc is also important for several other health reasons, the more the better.
Besides, it's too expensive to change the piping and why give up chocolate?
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