January 13, 2014
Depression May Be Linked to Low Zinc Levels
Because soils in the United States are generally low in levels of zinc, this may well be factual and part of the depression problem. Granted this is the determination of a meta-analysis and not a large controlled study. In addition, the authors list some weaknesses of the studies they used. Association studies cannot determine the direction of causation, a causal association between zinc status and depression is biologically plausible.
Zinc does have antioxidant properties, it helps to maintain endocrine homeostasis and immune function, and zinc plays multiple roles in regulating the hippocampal and cortical glutamatergic circuits that sub serve regulation and cognitive function. Thus, changes in zinc homeostasis might compromise neuroplasticity and contribute to long-term neuropsychological and psychiatric decline. Homeostasis is the tendency of a system, especially the physiological system of higher animals, to maintain internal stability, owing to the coordinated response of its parts to any situation or stimulus that would tend to disturb its normal condition or function.
People who are depressed were found to have lower concentrations of zinc in their peripheral blood compared with nondepressed individuals, a meta-analysis suggests. The pathophysiological relationships between zinc status and depression, and the potential benefits of zinc supplementation in depressed patients, does warrant further investigation. This is the conclusion of author Walter Swardfager, PhD, from the Sunnybrook Research Institute, University of Toronto, Canada, and colleagues. Their findings were published in the December 15 issue of Biological Psychiatry.
The analysis included 17 studies that measured peripheral blood–zinc concentrations in 1643 depressed patients and 804 control participants. Ten of these studies reported on psychiatric inpatients, and seven reported on community samples. Of the participants, 34.4% were male; the mean age was 37.7 years.
I found no mention in the study about whether the following vitamins, B12 and B6, which can also influence depression were even considered. From my research, I know that vitamin B12 and vitamin B6 can influence depression. From the Oregon State University the following is quoted from depression - “Because a key enzyme in the synthesis of the neurotransmitters serotonin and norepinephrine is PLP-dependent, it has been suggested that vitamin B6 deficiency may lead to depression. However, clinical trials have not provided convincing evidence that vitamin B6 supplementation is an effective treatment for depression, though vitamin B6 may have therapeutic efficacy in premenopausal women.”
Also from the Oregon State University, this is quoted from the vitamin B12 - “Observational studies have found as many as 30% of patients hospitalized for depression are deficient in vitamin B12. A cross-sectional study of 700 community-living, physically disabled women over the age of 65 found that vitamin B12 deficient women were twice as likely to be severely depressed as non-deficient women. A population-based study in 3,884 elderly men and women with depressive disorders found that those with vitamin B12 deficiency were almost 70% more likely to experience depression than those with normal vitamin B12 status.”
Rather than purchasing and taking zinc supplements, I would suggest that you talk this over with your doctor and have the doctor test for serum zinc deficiency. Be careful, as many doctors will declare that this is “all in your head.” A member of our support group had a relative with depression and this was the answer she received. The doctor also said the same for B12 and B6 and refused to test for them.
We are thankful that our local doctor, Dr. Tom, as we have nicknamed him, that knows our group fairly well now, did the tests for Sue's relative and discovered she was severely deficient for zinc, iron, and vitamin B12. He gave a series of shots for the B12 and started her on iron supplements immediately. He said because iron could prevent the uptake of zinc, he wanted her iron levels in the normal range before she took any zinc supplements. Sue's relative recovered from her depression before she started on the zinc supplement. There were other vitamins that the doctor discovered she was in the low range for and they started tackling them with food to start, and when one still tested low, he prescribed a supplement for it.
We have invited him to speak to a joint meeting of his support group and our group in January. He has accepted this.