Zinc intake from either a quality diet or supplementation has been shown to significantly improve the symptoms of depression, reduce the risk of depression, and improve mood in patients non-responsive to antidepressant medications. 1,2
Results from a 2018 systematic review revealed the following:
- Zinc is categorised as one of twelve antidepressant nutrients that is involved in both the prevention and treatment of depressive disorders (mood foods).3
Findings from previous clinical trials and systematic reviews reveal:
- Insufficient zinc is associated with neuropsychiatric presentations such as altered behaviour, reduced ability to learn and depression.4
- Low serum zinc levels are consistently seen in depressed patients, with lower zinc associated with greater depressive symptom severity (i.e. the lower the zinc, the worse the depressive symptoms).5
How much do I need?
The recommended dosage for adults is as follows:
- >11mg through dietary intake to reduce the risk and/or the symptoms of depression.6,7
- 25mg to reduce the symptoms of depression when used in addition to common anti-depressants.8,9
How long does it take to work?
- A majority of studies indicate results are generally achieved after 12 weeks, depending on the person and other lifestyle factors.9
- Diets high in zinc are consistently associated with a reduced incidence of depression (eat a consistent quality diet that contains a reasonable amount of zinc).6,7
How zinc works for depression
According to the research, zinc is said to:
- Promote the expression of Brain Derived Neurotrophic Factor (BDNF) and therefore influence neuroplasticity. 3 BDNF levels are often decreased in depressed patients and down regulation of BDNF also decreases neuronal plasticity.1
- Have a positive effect on neurotransmitter activity involved in depression, such as the serotonergic, dopaminergic and glutamatergic systems.1
- Inhibit the glutamate ionotropic NMDA receptor complex (inhibits NMDA ionotropic channels, thereby preventing neuronal injury, neural dysfunction, depression and other psychiatric illnesses).1 Antagonists of the NMDA receptor have antidepressant-like effects. 2
- Reduce markers of inflammation, including C-reactive protein (CRP), Interleukin-6 (IL-6), and tumor necrosis factor (TNF-α). 1 (Depression is often accompanied by an activation of the inflammation response).10
- Play an important role in antioxidant systems, and therefore help reduce the oxidation that can contribute to depression.1
- Stimulate the release of the inhibitory neurotransmitter GABA, which inhibits excessive glutamate release and therefore neuronal death.2
- Be one of the most prevalent trace elements in key areas of the brain including the amygdala, hippocampus, and neocortex. Zinc is involved in hippocampal neurogenesis (the creation of new brain cells) through the upregulation of BDNF.8
- Help maintain endocrine homeostasis and immune function and play a significant role in regulating hippocampal and cortical glutamatergic circuits.5
Can I get sufficient zinc through diet?
In short, the answer is yes. As described above, studies indicate that sufficient zinc intake from the diet is associated with a significant reduction in the risk of depression.
To ensure you are getting enough zinc from your diet, though, the key is to reduce or avoid processed foods as much as possible. Processing foods removes a significant portion of the zinc.
If you are wanting to ensure you get a specific dosage of zinc daily, or need help to work out which foods contain sufficient zinc, you may consider checking out our blog post Discover What Nutrients Are Hidden in Your Food or including a high quality zinc supplement such as zinc citrate.
Factors to be aware of include:
- Refined grains, such as white flour can remove 75% of zinc as compared to the wholegrain.11
- Vegetarian diets are at risk of zinc deficiency and strict vegetarians may require increased zinc intake due to phytic acid (found in legumes and grains), which inhibits zinc absorption.12
- Food preparation techniques such as soaking black beans can reduce phytates and other anti nutrients that inhibit zinc absorption, thereby maximising the zinc content of these foods.13
- Many common medications such as diabetic medications, anticonvulsants, antacids, diuretics, steroids and anti-inflammatories can impact zinc absorption.2
- Alcoholism can impair zinc absorption.2
- High doses of supplemental iron (38mg to 65mg/day of elemental Iron) can decease zinc absorption.12
It all seems pretty straight forward but unfortunately, as with most things that provide real benefits, you can’t take the easy option.
The science clearly indicates that the quick and easy foods we see popping up on the shelves are low in zinc and setting you up for failure. To get the most out of your food you need to take control of your diet and incorporate non-refined foods with plenty of fresh fruit and vegetables.
In general, shellfish, beef and other red meats are high animal-based zinc sources, and nuts and legumes are good options if you’re choosing plant based sources.
|Beef (rump steak)||100 grams||8.2mg|
|Cashews (raw)||30g (20 nuts)||1.6mg|
For a full list of foods check out:
- Food Standards Australia New Zealand14 and choose zinc on the browse nutrient list OR;
- United States Department of Agriculture Food Composition Database15 and search zinc in the Nutrient search
You can also check out our post Discover What Nutrients Are Hidden in Your Food.
Disclaimer: This information is designed as a guide only. As with all information listed on MindfulMoo.com, we recommend consulting your GP or medical practitioner before making any changes to your diet or lifestyle.
References & further resources
- Li Z, Li B, Song X, Zhang D. Dietary zinc and iron intake and risk of depression: A meta-analysis. Psychiatry Res. 2017;251(January):41-47. doi:10.1016/j.psychres.2017.02.006.
- Petrilli MA, Kranz TM, Kleinhaus K, et al. The emerging role for zinc in depression and psychosis. Front Pharmacol. 2017;8(414):1-12. doi:10.3389/fphar.2017.00414.
- Lachance LR, Ramsey D, Ramsey D. Antidepressant foods: An evidence-based nutrient profiling system for depression. World J Psychiatry. 2018;8(3):97-104. doi:10.5498/wjp.v8.i3.97.
- Frutos MJ, Valero-Cases E, Rincon-Frutos L. Food components with potential to be used in the therapeutic approach of mental diseases. Curr Pharm Biotechnol. 2018;19(10):1389-2010. doi:10.2174/1389201019666180925120657.
- Swardfager W, Herrmann N, Mazereeuw G, Goldberger K, Harimoto T, Lanctôt KL. Zinc in depression: A meta-analysis. Biol Psychiatry. 2013;74(12):872-878. doi:10.1016/j.biopsych.2013.05.008.
- Kim T, CHoi J, Lee H, Park Y. Associations between Dietary Pattern and Depression in Korean Adolescent Girls.J Pediatr Adolesc Gynecol. 2015;28(6):533-537. doi://dx.doi.org/10.1016/j.jpag.2015.04.005.
- Byles J, McElduff P, Vashum KP, et al. Dietary zinc is associated with a lower incidence of depression: Findings from two Australian cohorts. J Affect Disord. 2014;166:249-257. doi:10.1016/j.jad.2014.05.016.
- Sarris J, Murphy J, Mischoulon D, et al. Adjunctive nutraceuticals for depression: A systematic review and meta-analyses. Am J Psychiatry. 2016;173(6):575-587. doi:10.1176/appi.ajp.2016.15091228.
- Lai J, Moxey A, Nowak G, Vashum K, Bailey K, McEvoy M. The efficacy of zinc supplementation in depression: Systematic review of randomised controlled trials. J Affect Disord. 2012;136(1-2):e31-e39. doi:10.1016/j.jad.2011.06.022.
- Dantzer R. Depression and inflammation: An intricate relationship. Biol Psychiatry. 2012;71(1):4-5. doi:10.1016/j.biopsych.2011.10.025.
- Balk J, Connorton JM, Wan Y, et al. Improving wheat as a source of iron and zinc for global nutrition. Nutr Bull. 2019;44(1):53-59. doi:10.1111/nbu.12361.
- Higdon J. An Evidence-Based Approach to Vitamins and Minerals. Thieme; 2003.
- Feitosa S, Greiner R, Meinhardt A-K, Posten C, Almeida D, Müller A. Effect of Traditional Household Processes on Iron, Zinc and Copper Bioaccessibility in Black Bean (Phaseolus vulgaris L.). Foods. 2018;7(8):123. doi:10.3390/foods7080123.
- FSANZ. Australian Food Composition Database. //www.foodstandards.gov.au/science/monitoringnutrients/afcd/Pages/foodsbynutrientsearch.aspx?nutrientID=ZN. Published 2019.
- USDA. USDA Food Composition Database. //ndb.nal.usda.gov/ndb/. Published 2018.