Depressed? It could be a mineral deficiency

When there’s presence of a zinc deficiency, there’s often a co-presence of an iron deficiency.

Both minerals are extremely important to cellular function and modulation of the nervous system.

Previously, a number of studies have shown that these minerals may influence the serotonergic, dopaminergic and glutamatergic systems — key neural transmission systems involved in depression.

Now, a scientific review has confirmed that both zinc and iron are associated with a higher risk of depression…

Like all micronutrients (vitamins and minerals), our body needs them. Surprisingly, even though we’re eating ample food, the large amounts of processed and packaged food consumed are leading to malnourishment, even in the Western world.

More than ever before, we are seeing a wide range of micronutrient deficiencies that appear to be increasing risk of multiple conditions — in this case it’s depression…

A malnourished brain shrinks

The hippocampus is the part of the brain responsible for memory, learning and emotion. In depression, it’s been shown that the hippocampus can shrink. Though it should be noted that this is not permanent. It can be reversed.

The hippocampus appears to be susceptible to zinc deficiency. This deficiency causes synaptic changes in the brain that alter brain chemicals called neurotransmitters, and contribute stress that may cause neurotoxicity. Subsequently, this may activate inflammatory and immune responses that only exacerbate the problem.

On the other hand, when there are adequate levels of zinc, several inflammatory markers are reduced. Zinc also promotes cell immunity, development and maturation. And since depression is associated with higher levels of oxidative stress, zinc acts as a powerful antioxidant to combat the negative effects of free radicals.

The body needs iron to regulate cellular function and synthesize DNA coding effectively. In terms of the brain specifically, iron oxygenates central brain tissues and is involved in synthesising neurotransmitters such as dopamine and serotonin.

While the role for iron in depression is less clear than zinc, researchers believe it prevents toxicity and alters certain functions in brain tissues.

One of the best ways to increase your levels of zinc and iron is to eat whole foods that contain them…

Dietary sources of zinc include:

  • Oysters – canned or fresh
  • Unsweetened cocoa
  • Wheat germ
  • Beef
  • Veal
  • Lamb
  • Sesame seeds and flour
  • Hemp seeds
  • Poppy seeds
  • Pumpkin seeds
  • Whey protein isolate
  • Egg yolk

The recommended dietary allowance (RDA) for adult men is 11 mg/ day and for women it’s 8 mg/ day.

Dietary sources of iron

Iron comes in two forms, heme iron and nonheme iron. Heme iron is more bioavailable than nonheme iron, which means the body absorbs it more efficiently.

Heme iron can be found in animal based foods:

  • Meats
  • Fish
  • Poultry
  • Seafood

Nonheme iron can also be found in animal foods but mainly comes from plant-based sources:

  • Quinoa
  • Spinach and other green leafy vegetables
  • Nuts and seeds
  • Unsweetened cocoa
  • Herbs and spices – parsley, turmeric, basil, thyme, spearmint, marjoram, cumin, oregano, dill, and so forth.

The presence of vitamin C in many plant sources such as vegetables and herbs assists with nonheme iron absorption. And so does eating nonheme iron with heme iron sources.

The RDA for iron is 8 mg/day for men and postmenopausal women, and 18 mg/day for premenopausal women.

You’ll notice that many sources or zinc and iron are animal foods, which puts vegetarians and vegans at increased risk of deficiency.

Also note that many breakfast cereals and packaged products contain ‘added’ minerals and while these may help correct deficiencies to some degree, these products also contain various negative ingredients (sugar, refined flour, omega-6 fats, additives, preservatives) that counteract any benefit they may provide.

To obtain the most bioavailable vitamins and minerals, it’s always best to stick to whole food sources as much as possible.

  1. Li Z, et al. Dietary zinc and iron intake and risk of depression: A meta-analysis. — Psychiatry Research. 2017;251:41–47.
  2. Micronutrient Information Center — (2014). Linus Pauling Institute. Retrieved 20 April, 2017
  3. USDA Food Composition Databases — (2017). Retrieved 20 April, 2017
Jedha Dening

By Jedha Dening

Jedha Dening is a qualified nutritionist (MNutr), researcher, author, freelance writer, and founder of type 2 diabetic nutrition site Diabetes Meal Plans. Her masters thesis on nutrition and inflammation was published and then presented at a national scientific conference. She has millions of words published in the health industry across various print and online publications. Having been in the field for over 15 years, she’s incredibly passionate about delving into the latest research to share the myths and truths surrounding nutrition and health. She believes when armed with the right knowledge, we’re empowered to make informed choices that can truly make a difference.