A weekend night at a sidewalk shellfish stall. A plate of hàu nướng mỡ hành (oysters grilled with scallion oil) arrives still sizzling, crushed roasted peanuts on top.
You ordered oysters because they are delicious. But without noticing, you just ate the food that tops the zinc rankings in almost every food database.
In this article
A tiny mineral that works in hundreds of places
An adult body holds only about 2 to 3g of zinc. About the weight of three peanuts.
But that small amount shows up in almost every cell. Zinc takes part in hundreds of enzymes, the little "machines" that run chemical reactions in your body. It is needed for:
- Making new cells and DNA. Wherever cells renew quickly, zinc is needed.
- Normal immune function.
- Taste and smell. Zinc is present in the cells that sense flavor and aroma.
- Skin healing after scrapes.
Your body has no big zinc store like its iron or B12 stores. So zinc needs topping up steadily through meals, day after day.
Needs are measured in a few milligrams a day, with men usually needing more than women. Vietnam's National Institute of Nutrition has specific recommendations (2016).
Oysters: the undisputed champion
Weight for weight, oysters have far more zinc than anything else in the kitchen. With some kinds of oyster, just a few can cover a large share of an adult's daily zinc need, or even more than all of it.
The exact numbers vary a lot by oyster variety, farming area and season. But the ranking barely changes: oysters come first, far ahead of the rest.
Why so much zinc? Oysters filter dozens of liters of seawater a day to feed, and they hold on to minerals from the water. Zinc is one of them.
The Vietnamese kitchen's zinc table
| Group | Examples | Absorption |
|---|---|---|
| Shellfish | Oysters, crab, blue swimmer crab, scallops, blood cockles, shrimp | Good |
| Red meat | Beef, lean pork, goat | Good |
| Poultry | Chicken thigh (more than breast), free-range chicken | Good |
| Eggs, dairy | Egg yolk, cheese, yogurt | Fair |
| Beans | Chickpeas, soybeans, black beans, tofu | Lower, blocked by phytate |
| Seeds and nuts | Pumpkin seeds, sesame, cashews, peanuts | Lower, blocked by phytate |
| Whole grains | Brown rice, oats | Lower, blocked by phytate |
A small detail gym-goers often miss: chicken thigh has more zinc than chicken breast. Dark meat works harder, needs more enzymes, and so holds more zinc.
Phytate: the "lock" in seeds and beans
Look at the table and you will see "phytate" repeated. It is the compound plants use to store phosphorus in seeds, waiting for the day they sprout.
Phytate has a habit: it grabs on to zinc, iron and calcium in the gut. Once zinc is held, your body struggles to get it out. That is why, for the same amount of zinc, meat is absorbed better than beans and seeds.
But our grandparents already had ways to pick the lock, even without calling it phytate:
- Soak beans overnight before cooking. The soaking water pulls out some of the phytate.
- Sprout them, like germinated brown rice or bean sprouts. As a seed sprouts, it breaks down its own phytate to get the phosphorus.
- Ferment them, like tương (fermented soybean sauce), chao (fermented tofu) or sourdough bread. Bacteria and yeast reduce phytate.
No need to avoid beans and seeds. They have plenty of other valuable nutrients. Just prepare them wisely.
How do vegetarians get zinc?
Vegetarians skip oysters and meat, so their zinc comes mainly from beans, seeds and grains. Because phytate gets in the way, vegetarians are often advised to eat a bit more zinc from food than meat eaters.
A few easy habits:
- A bean or tofu dish at every meal.
- Sprinkle seeds on your food: toasted sesame on greens, pumpkin seeds in salads, peanuts on nộm (Vietnamese herb salad).
- Switch to fermented or sprouted grains when you can.
- Eggs and yogurt if you are lacto-ovo vegetarian.
A reminder: long-term high-dose zinc pills can block the absorption of copper, another mineral. More is not always better. If you have particular needs, ask a health professional.
Inside the kOBE kitchen
kOBE's Sous Vide chicken thighs use whole chicken leg quarters, dark meat that naturally has more zinc than breast. They come in four flavors: Monk Fruit Glazed, Lemongrass Chili, Black Pepper and Chili Salt.
For vegetarians, ready-cooked Chickpeas and Edamame are two easy beans to add to a lunchbox. We do not list zinc numbers on our products, so we will not give a figure. But a meal with beans plus the toasted sesame in Sesame Kale is already following the "many small sources add up" idea. See our ready-cooked ingredients.
Frequently asked questions
Is there a zinc difference between raw and grilled oysters?
Can eating lots of oysters give you too much zinc?
Are pumpkin seeds high in zinc?
Keep reading
Sources
- Lönnerdal B. (2000). Dietary factors influencing zinc absorption. Journal of Nutrition 130(5S Suppl):1378S to 1383S.
- WHO and FAO (2004). Vitamin and mineral requirements in human nutrition, 2nd ed., chapter on Zinc.
- USDA FoodData Central (oysters, beef, chicken thigh, chicken breast, pumpkin seeds).
- National Institute of Nutrition (Vietnam) (2016). Recommended Dietary Allowances for Vietnamese People [Nhu cầu dinh dưỡng khuyến nghị cho người Việt Nam].
- Further reading: Understanding Nutrition 16th ed., chapter 13.
