Think Zinc for Winter Wellness

Just a few weeks past winter solstice, and we’re deeply entrenched in sick season. One simple way to combat viruses and infections is to eat foods containing certain nutrients that support immunity.

Zinc is a potent antioxidant, often misunderstood and under-consumed. Prevalent in all tissues, organs and body fluids, zinc is essential for cell growth and structural integrity (including the skin and bone formation); nutrient metabolism; reproduction; immunity and defense (including wound repair); and is involved in more biochemical reactions in the body than any other trace nutrient. During winter cold season, zinc sufficiency will help you stay well, while insufficiency can make you more susceptible to disease and illness. 

We humans don’t make zinc in the body and must obtain this essential mineral from food or other sources. Supplementation is a viable option for zinc, but supplementation via liquid or tablets often supplies too much zinc, which may lead to decreased absorption and utilization, and increased excretion.

It’s evidence of the brilliance of Mother Nature – intentionally supplying zinc in small amounts in a wide range of whole food we would be eating seasonally anyway (if packaged food were not an option). When we eat zinc daily in small amounts in every meal vs. in occasional higher-dose supplementation, we maintain optimal levels of zinc truly essential for survival. 

Not surprisingly, many factors affect zinc absorption – another brilliant plan of nature. For example, dietary phytic acids found primarily in plants (grains, seeds, nuts and legumes) inhibit zinc absorption. Why so? One can surmise that we humans are supposed to consume more foods than just grains, seeds, nuts and legumes in order to obtain all the nutrients we actually need. Or, perhaps, relying on a plant-based diet actually helps our bodies maintain zinc balance by including foods that prevent us from consuming too much zinc.

Either way, zinc is found naturally in both animal and plant foods, thus eating a variety of whole foods leads to diets comprising of ample zinc intake. Without relying too much on “numbers”, such as exact amounts of zinc an individual “should” consume daily, let’s focus instead on zinc-containing foods to inspire us to consume more of them this season.

The highest zinc concentration exists in seafood, primarily oysters (3 medium oysters equates to 100-200% of an adult’s daily needs), crab and shrimp. One 3 oz. serving of pasture raised lamb offers about 50% of an adult’s daily zinc needs, and pasture-raised beef, turkey and chicken contain smaller levels of zinc (9-18% of daily intake per serving). Dairy, such as kefir and yogurt, also contain some zinc.

The richest plant-based zinc sources are nuts and seeds (especially sesame, pumpkin, sunflower, flax and cashews); lentils; legumes (chickpeas, peas, soybeans/tofu); and grains (quinoa and oats). Smaller levels of zinc are present in spinach, mushrooms and asparagus.

Vegans and vegetarians may need to double their intake of zinc-containing foods, in part because higher levels of phytates from whole grains and legumes may inhibit zinc absorption. Contrarily, individuals who eat a lot of meat (high in iron) can experience zinc insufficiency because iron also inhibits zinc absorption.

Too confusing? Let’s simplify: a balance of whole foods equates to a balance of nutrients. Our body systems constantly keep the body in check. All we have to do is what nature intends: eat wholesome foods from the earth.

REFERENCES & RESOURCES

Roohani, N., Hurrell, R., Kelishadi, R., & Schulin, R. (2013). Zinc and its importance for human health: An integrative review. Journal of research in medical sciences: the official journal of Isfahan University of Medical Sciences, 18(2), 144–157.

Gropper, S., Smith, J. (2013). Advanced Nutrition and Human Metabolism, 6th ed. Independence, KS: Wadsworth Publishing, Cengage Learning.

McGuire, M.S. & Beerman, K.A. (2013) Nutritional Sciences: From Fundamentals to Food. 3rd Ed.). Independence, KS: Cengage Learning.

Shah, D., Sachdev, H.S., Gera, T., Fe-Regil, L.M. & Pena-Rosas, J.P. (2016). Fortification of staple foods with zinc for improving zinc status and other health outcomes in the general population. Cochrane Database of Systematic Reviews, 6. doi: 10.1002/14651858.CD01697.pub2.