Most folks probably do not give a whole lot of thought to their zinc intake, but apparently, if your diet is lacking, one of the consequences is depression. Doctors who use an orthomolecular approach to treating depression such as those at the Carl Pfieffer Centers or authors Joan Matthews Larson and Julia Ross have for decades examined their patients’ zinc levels. They have found what researchers are only beginning to document – that improving your zinc status from a deficiency state can improve your mental function.
Zinc and Depression
The clinical trial evidence for the zinc-depression link is still slim, but researchers do give us cause to believe that the two are related:
- Low levels of zinc are correlated with depression (Maes 1994; Nowak et al. 2005).
- The lower the zinc levels, the worse the depression. One study found that patients with lower serum zinc also tended to have major depression and those with intermediate zinc levels (borderline) tended to have minor depression (Maes et al. 1994).
- Clinical trials improve depression. In a double-blind and placebo-controlled study, patients felt better after six weeks if they were also taking zinc supplements (Nowak et al. 2003 ~ PDF).
- Zinc can complement antidepressant therapy. Patients in the Nowak et al. 2003 study were also on antidepressant medication. The zinc therapy improved their depression above the relief provided by the medication.
- You might be able to increase your brain zinc levels very quickly, today, if you have shock therapy. Nowak et al. (2005) find that shock therapy increases brain levels of zinc in the rat brain. But this is not a great strategy either since it doesn’t fix the underlying zinc problem in the longer term.
Low Zinc Body Signs
Doctors may offer their patients a red blood cell zinc test to identify deficiencies but often our bodies give us signs that extra zinc may be in order. Zinc is critical for tissue growth and a low zinc status is often accompanied by:
- Soft or thin fingernails
- White spots on fingernails
- Slow hair growth
- Stretch marks on skin
A child’s size may be related to his or her zinc status. I have wondered over the years if my extra-small son is extra-small in part due to low zinc in pregnancy. Some children are just small, but as a mom, I do wonder. The good thing in such a case is that more zinc in the diet will help a small child grow.
Zinc is found most densely in the animal world, particularly in:
Vegetarians tend to rely on grains and legumes for zinc, but only about 15 percent of that zinc will be useable to your body. That percentage will be closer to 10 percent if the food source is a high-phytate, low-phytase food like soy. If you are a vegetarian and concerned about low zinc, read about phytic acid on the phytic acid website. There are simple kitchen preparation techniques to increase your absorption of zinc in the foods you are already eating.
If low zinc is aggravating your depression, take a zinc supplement as a short-term strategy. Modify your diet for the long term. But I should note that you should not take zinc supplements if you have no evidence that you are deficient. Too much zinc can become toxic. The amino chelate forms of zinc tend to be absorbed well. The commonly available form of zinc, zinc oxide, is absorbed least well. Zinc supplements are usually about 40 milligrams per day and some include copper because zinc supplementation can reduce copper absorption (DiSilvestro 2004).