Zinc! It’s the essential mineral that’s praised by many advocates involved in the Paleo community. Most people generally recognize zinc for its reputation as a potent cold and flu virus prevention solution, but its numerous benefits also extend beyond its role as an immunity-boosting mineral.
Ensuring adequate zinc intake in one’s diet is absolutely necessary for achieving long term health goals while following an ancestral eating plan. Zinc is essential for maintaining numerous physiological functions within the human body including tissue and epithelial integrity, immune system regulation, cellular growth, gut health, and inflammation suppression. The current USA government’s recommended daily allowance (RDA) for zinc averages in at approximately 10 mg. The USA RDA for zinc might be adequate for maintaining proper zinc levels for most healthy human beings that do not suffer from a zinc deficiency, but higher short-term dosages are likely needed to correct a deficiency. Physical indications of zinc deficiency include but are not limited to frequent viral infections, white spots or streaks on the fingernails, poor physical growth in childhood, hair loss, impaired vision, diarrhea, acne, dandruff, chronic dry skin, and impaired mental functioning (i.e. depression, anxiety, brain fog). It’s worth noting that all of the listed conditions can also result from the manifestation of other nutrient and mineral imbalances, and ensuring a highly varied nutrient rich ancestral diet that is rich in omega-3’s is crucial to preventing and resolving any of the aforementioned health issues.
Zinc in excess can be equally problematic as zinc deficiency. The daily upper limit threshold for zinc in healthy individuals is about 40 mg for adults over 19 and 25mg for those under 19. Excessive zinc consumption is characterized by severe headaches, nausea, vomiting, and decreased appetite. Over the long term, excessive zinc intake in the absence of copper will result in the gradual depletion of copper from the human body. For this reason it is recommended that those looking to supplement zinc in their diets should avoid zinc dietary supplements and instead opt for “au-naturel” food-based sources of zinc that are inherently proportionately balanced with copper.
Those looking to ensure optimum zinc intake in their diet must decide whether to source their zinc from animal sources or plant sources. Below are two tables demonstrating a handful of the highest ranking sources of zinc from both plants and animals. The zinc content of each source is listed in mg. Note that many of the listed zinc-rich plant foods do not adhere to the Paleo lifestyle.
When examining the table above, it becomes obvious that ratio of zinc in animal-based foods is significantly higher than the ratio of zinc found in plant-based foods. Additionally, all of the animal-based sources of zinc naturally have appropriate zinc to copper ratios, so you don’t have to worry about creating a mineral imbalance while consuming these foods.
Now you might be wondering if it is still worth considering plant-based sources of zinc in your diet. From the tables above, it is immediately apparent that one would have to consume much higher quantities of zinc-containing plant foods to achieve the same proportion of zinc found in the animal foods listed above. Besides pumpkin seeds and sunflower seeds, all of the other listed plant-based zinc sources are off limits for Paleo followers. Additionally, it is worth mentioning that many of the zinc-rich plant foods such as legumes, seeds, nuts, and grains contain phytates (i.e. phytic acid). Phytates have been demonstrated to bind to zinc and other important dietary minerals such as iron and manganese. The bonding of phytates with zinc and other minerals upon digestion drastically reduces your body’s ability to absorb these key minerals, thus making you more prone to mineral deficiencies. Animal foods do not inhibit the absorption of zinc or other minerals and instead aid in absorption during digestion.
Oysters rank supreme amongst all other zinc containing food sources available for human consumption, and thus are ideal for treating individuals with zinc deficiency, and for those simply looking to incorporate zinc-rich food sources into their diets.
Oysters have long been revered for their rich taste and nutritional qualities across all parts of the globe. Preference for oyster consumption has shown up in historical documentation dating back to the ancient Greeks and Chinese. In fact, in Europe up until the 18th century oysters were considered a “luxury” food only reserved for the highest classes. Within the colonies of North America, oyster consumption was never restricted to the rich and thus most colonists and Native Americans consumed oysters regularly. The 19th century in The United States was marked by the widespread establishment of “oyster bars” that originated on the eastern seaboard and quickly became popular throughout the west. By 1881 there were nearly 379 oyster bars in Philadelphia alone! Zinc deficiency was likely not a major problem for oyster-loving 19th century Americans.
Nowadays oysters are becoming an increasingly obsolete food source. Oysters can be difficult to source fresh, especially if you are like myself and live thousands of miles inland from the nearest ocean. The best economical solution for inlanders is to purchase canned oysters from your local grocery store. A large majority of the oysters on store shelves are canned in cottonseed oil, which you will definitely want to avoid if you are sticking to a Paleo eating plan. Fortunately, Crown Prince offers a line of smoked oysters that are canned in extra-virgin olive oil. I have seen these oysters available in Sprouts, Whole Foods, and Trader Joe’s for about $2 – $3 per can. If you are not quite adjusted to the “delicious” taste of oysters yet, try topping them with a few drops of Paleo-friendly hot sauce.
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4. Ma, J., & Betts, N. M. (2000). Zinc and copper intakes and their major food sources for older adults in the 1994–96 continuing survey of food intakes by individuals (CSFII). The Journal of nutrition, 130(11), 2838-2843.
5. Office of Dietary Supplements – Zinc. (n.d.). Retrieved December 28, 2015, from https://ods.od.nih.gov/factsheets/Zinc-HealthProfessional/