After iron, zinc is the most abundant mineral in our bodies. It is found in literally ever part of the body but has the biggest concentrations in the eyes and prostate. Which is why zinc deficiency can cause vision problems and (in men) fertility problems. Symptoms of zinc deficiency include fatigue, mental lethargy, diarrhea, skin lesions, white spots on nails, and slow wound healing. There are many vegan sources of zinc. However, these vegan zinc sources also contain high levels of antinutrients which block zinc absorption. So, some of those zinc foods might not be such good sources of zinc after all.
| Weird Zinc Fact: Men can lose up to 15mg of zinc in a single ejaculation! Since one of the symptoms of zinc deficiency is poor vision, maybe that age-old adage that masturbation leads to blindness has some truth to it! |
Zinc Antinutrients: Should Vegans Be Worried About Zinc?
An antinutrient is a substance which blocks nutrient absorption. In the case with zinc, chemicals called phytates are antinutrients (this includes phytic acid). Phyates chelate (bind) with zinc, preventing your body from absorbing it. High phytates foods include whole grains, seeds, and nuts. These also happen to be where most vegans get their zinc from.
One commonly-cited study from the WHO found that people on vegetarian and vegan diets who ate high amounts of grains (which contain phytates) absorbed only about 15% of dietary zinc. By comparison, people eating meat and fewer grains had a zinc absorption rate of 50-55%.
Other zinc antinutrients include flavonoids (which are a type of plant pigmant found in fruits, tea, chocolate, and dry beans, amongst others). Alcohol also acts as a zinc antinutrient, so a lot of alcoholics (and I’d imagine college students also) are zinc deficient.
The World Health Organization Estimates that 2 billion people – or roughly 1/3 of the world’s population – is zinc deficient. This doesn’t necessarily mean that vegans should be concerned. Zinc deficiency is mainly a problem in impoverished countries. In high-income countries, the prevalence of zinc deficiency is fairly low at about 4-8% of the population. Still, since zinc is such a crucial nutrient in our diets, it is worth taking at to see if you are getting enough.
How Much Zinc Do Vegans Really Need?
To make matters worse, vegan sources of zinc already have a low bioavailability compared to animal-sources of zinc, meaning your body doesn’t absorb the vegan zinc very well. This, combined with the antinutrient problem, has led many health experts like the Institute of Medicine to recommend that vegans and vegetarians consume 50% more than the RDA for zinc.
Zinc RDA:
- Omnivores: 8mg/day for adult women and 11mg/day for adult men
- Vegetarians and Vegans: (based on the recommendation to consume 50% more than the omnivore RDA for zinc) 12mg/day for adult women and 16.5mg/day for adult men
Symptoms of Zinc Deficiency
Mild zinc deficiency might not produce very noticeable symptoms, or the symptoms (like low energy) could easily be attributed to another problem. Plus, if you are deficient in zinc, then you likely are deficient in other nutrients as well, especially iron, since these minerals are found in the same foods. Here are just some of the symptoms of zinc deficiency you should be on the lookout for.
- Brittle nails with white spots on them
- Poor immunity, frequently sick
- Fatigue
- Poor appetite
- In men, symptoms of low testosterone (low libido, erectile dysfunction, poor ejaculations…)
How to Make Sure You Are Getting Enough Zinc on the Vegan Diet
There are three ways that vegans can make sure they are getting enough zinc in their diets.
1. Increase Consumption of Zinc Foods: Strive for the 150% RDA of zinc that is recommended for vegetarians and vegans by the Institute of Medicine
2. Reduce Antinutrient Consumption: You can try to avoid foods which are high in phytates and tannins (such as not drinking tea with your meals), and also avoid alcohol. There are also several ways to reduce the phytates content in foods. The Weston A. Price Foundation (which is rather obsessive in the issue of antinutrients) says that fermenting grains, sprouting seeds, and soaking nuts all significantly reduces phytic acid content.
3. Increase Cofactors for Zinc Absorption: Just like some substances block zinc absorption, others can help increase zinc absorption. Consuming protein with zinc is one way to boost absorption. If you are going to take a zinc supplement, then you will want to take it with food so improve absorption.
Vegan Sources of Zinc
Walnuts: 1 ounce (about 14 walnut halves) = 0.9 mg zinc
Recipe Idea:
Eat them with mashed potatoes. The walnuts give the potatoes an exciting new texture. Try adding walnuts and artichokes to garlicky mashed potatoes. Or you can go the tangy route and try mashed sweet potatoes with orange juice and walnuts.
Pepitas: 1 ounce = 2.1 mg zinc
Recipe Idea:
Pepitas are great on just about any salad because they add an exciting crunch.
Tahini: 1 tablespooon = 0.7 mg zinc
Recipe Idea:
Use in an awesome dressing for a tofu and veggie salad
Peanut Butter: 2 tablespoons = 0.9 mg zinc
Recipe Idea:
Use as a tasty sauce for Asian noodles and veggies. Just mix 3 tablespoons of peanut butter with 2 tablespoons of soy sauce, 1 spoonful of lemon or lime juice, 1 tablespoon of sesame oil, and as much garlic and chili as you like.
Wild Rice: 1 cup = 2.2 mg zinc
Recipe Idea:
The nutty flavor of wild rice makes it perfect for blending up in creamy soups.
Quinoa: 1 cup = 2.0 mg zinc
Recipe Idea:
Quinoa isn’t just a good vegan source of zinc. It is also a complete protein and loaded with minerals and vitamins. Top it with lentils or chickpeas, or use it to make tasty veggie burgers.
Wheat Germ: 1 tablespoon = 1.7 mg zinc
Recipe Idea:
There are a lot of ways to get more wheat germ into your diet. Consider adding a scoop to your morning smoothie, using bran instead of flour as a thickener for soups, or adding to veggie dips.
