We have so much is in New Zealand, surrounded by some of the most stunningly natural beauty in the world. The land that gives us so much inspiration and joy may also be part of the problem in causing the New Zealanders to have one of the highest rates of mood disorders such as depression in the world. (*1)
Low Zinc in the Soil
The problem lies in part in the land itself. The soil in New Zealand is low in many important nutrients, such as zinc, magnesium, selenium, boron and iodine. The food choices we make can compound that problem. If you eat little food which naturally contains these minerals; and that food has been grown in soil which is depleted you are likely to have health problems triggered by deficiencies of the minerals.
Diet can Deplete Zinc and Trigger Depression and other problems
You may make things worse by having a diet which depletes your body further of the minerals.
Here Ill tell you a little about how low zinc levels in your body can increase your risk of suffering from depression.
Zinc is an essential mineral, when your body does not enough, you are more likely to suffer not only from mental health problems particularly depression[2-4],but you are also at increased risk of lowered immunity, immunity and chronic diseases, such as cancer and type 2 diabetes. A study this year of 402 students found those who had the most zinc in their diet were least likely to have depression. 
The knowledge that low zinc is likely in depression is not new, over 20 years ago zinc levels in the body were found to be lower in people with depression.
Supplementing With Zinc and/or Pharmaceutical Antidepressants
Supplementation of zinc has an antidepressant effect [1, 8-10] it seems to help whether people find pharmaceutical antidepressants helpful or not[2, 11, 12]. Studies have shown zinc has an effect on the chemicals in the brain which are involved in depression[9, 13]. It is not necessarily a case of choosing between pharmaceutical antidepressants or zinc. Zinc has been shown to improve the effect of some antidepressants (imipramine and citalopram) .
Zinc in the Nervous System and Brain
It is fairly logical that zinc is important to mental health since in the body zinc is found (mainly ) in the brain, so is very important for the health of the nervous system). When zinc is low in the diet a number of nervous system problems may result including problems with memory, a symptom often experienced with depression[9, 11]. With this in mind it is not surprising that zinc deficiency is common is the elderly.
Depression and Inflammation
Some new ideas on the causes of depression suggest inflammation in the body could result in less new nerve cells being formed and more nerve cells wearing down. In patients with major depression, low zinc levels appear to be related to increased inflammation [11, 12].
In a large study this year found inadequate zinc in the diet of women contributed to depressive symptoms and for those taking pharmaceutical antidepressants supplements of zinc helped relieve their symptoms.
Many factors contribute to depression
Certainly many factors contribute to depression, increased stress can trigger depression, however adequate zinc intake appears buffer the impact of stress, and decrease likelihood of depression.
Other nutrients may be low in depression
FOOD STATE ZINC and absorption
It is very important that if you take a zinc supplement you do not have a dose too high for your body. Too much zinc, more than 40 mg a day can be toxic to the body. Iron in some supplement forms reduces the availability of zinc, however iron in food or in the food state supplement form will not affect the absorption of zinc. Always be careful if supplementing your diet with zinc as too much zinc can have detrimental effects on immunity and other aspects of your health. Food State supplements are all of a safe low dose since studies show they are absorbed more easily into the body than other forms of supplement forms, in addition since they are in same form as food there is no problem taking food state iron supplements at the same time. (*16,*17)
Foods containing zinc
Foods that contain zinc include meat (best organic), poultry (best organic) sh, seafood esp. oysters, grains, pumpkin seeds, sunflowers seeds mushrooms, organic soybeans, and brewers yeast[18, 19]. Animal protein helps with zinc absorption, so vegetarians need to be especially careful to get adequate zinc.[4, 20].
Substances which Lower Zinc
Cadmium a toxic element also depletes zinc. The commonest sources of toxic levels of cadmium is cigarette smoke (stop smoking now!). If you find you cannot stop smoking immediately supplements of zinc may help to decrease the immune damage caused by cadmium. But there are many more damaging aspects of smoking so work towards quitting as soon as possible.
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