There’s a reason Hippocrates once said, “let thy food be thy medicine and thy medicine be thy food”—there is power in the foods we eat. Zinc-rich foods have been used for health and healing for centuries. Even the forefathers of modern medicine understood the importance of nutrition. Although zinc is mostly known for its role in strengthening the immune system and shortening the duration of minor illnesses like colds and flu, new research supports the idea that eating zinc-rich foods may have even more benefits than once thought.
Scientists are finding that zinc-rich foods may influence the immune response and reduce inflammation and could also improve your overall health and vitality. Zinc is also an essential trace element required by various organs in the body to function properly such as those of the digestive system and thyroid gland. Zinc-rich foods have may also have additional benefits related to:
- Controlling diabetes
- Reducing stress levels
- Boosting energy
- Increasing metabolism
- Healing acne and wounds
- A proper sense of taste and smell
What is Zinc?
Zinc is an essential mineral, which is basically a chemical element or nutrient required by living organisms to perform the functions necessary for life. There are 16 essential minerals including calcium, phosphorus, potassium, sulfur, sodium, chloride, magnesium, iron, zinc, copper, manganese, iodine, and selenium, molybdenum, chromium, and fluoride. Minerals cannot be made by living organisms but must instead come from food.
Zinc is naturally present in some foods and added to others and is available as a dietary supplement. It is also often found in cold lozenges or over-the-counter cold remedies.
Your body cannot store zinc; therefore, daily intake of this element through food or supplements is necessary.
How Important Are Zinc-Rich Foods?
Zinc is required for the catalytic activity or chemical reactions of approximately 100 enzymes involved in protein synthesis, DNA synthesis, and cell division. Zinc-rich foods also play an extremely important role in growth and development during pregnancy, childhood, and adolescence.
Research has Concluded that Zinc-Rich Foods Are Important for Overall Wellness
A recent study published in the Molecular Nutrition and Food Research Journal has linked low levels of zinc to an increased risk of chronic diseases, including:
- Heart disease
Additional research performed on mice of various ages found a possible inverse correlation between zinc and inflammation. Elderly mice had lower levels of zinc, higher levels of inflammation, and decreased IL-6 methylation, which is an important mechanism that controls gene expression.
In the absence of zinc, immune cells were shown to respond by increasing inflammation. The researchers also found that low levels of zinc are correlated with abnormal immune cell activation and impaired production and signaling of anti-inflammatory cytokine IL-6.
How Much Zinc Should We Consume to Keep Our Bodies Working Optimally?
Consuming zinc-rich foods or taking zinc supplements daily is vital to maintaining healthy level of zinc at all times. The following table presents the recommended dietary allowance (RDA) of zinc according to age.
|0–6 months||2 mg||2 mg|
|7–12 months||3 mg||3 mg|
|1–3 years||3 mg||3 mg|
|4-8 years||5 mg||5 mg|
|9-13 years||8 mg||8 mg|
|14-18 years||11 mg||9 mg||12 mg||13 mg|
|14-18 years||11 mg||8 mg||11 mg||12 mg|
A wide variety of zinc-rich foods are available for daily consumption. Although red meat and poultry provide the majority of zinc in the typical American diet, there are numerous other healthy sources to choose from. The bioavailability of zinc in plant-based foods such as bread, cereals, and legumes are slightly lower than in animal products but can still provide a good source of this crucial mineral.
Zinc is present in small traces in most foods. Here’s a list of zinc-rich foods that can be included in your daily meals to ensure you’re getting a regular supply of zinc.
- Avocados, also known as the single-seeded berry, are an excellent source of zinc. One cup offers a massive one milligram of the essential nutrient.
- Apricots are a zinc-rich food and the quantity of zinc increases when they are dried. One cup of fresh apricots contains approximately 0.33 mg of zinc and the dried version offers around 0.50 mg.
- Prunes are another zinc-rich fruit, offering 0.77 mg per cup, and are a sweet-tasting choice.
- Blackberries and raspberries are full of zinc. Consuming one fresh cup of these berries along with your daily cereal or yogurt can provide you with 0.52–0.53 mg of zinc.
- Raisins and dates are also classed as zinc-rich foods and can both can add 0.32 mg of zinc to your daily diet.
- Kiwis are loaded with nutrients, and one of the most abundant is zinc. One cup of this exotic green fruit provides approximately 0.25 mg of zinc.
- Bananas are well known to be a readily available source of potassium, but they also contain trace amounts of zinc. A nine-inch banana has around 0.23 mg of this important mineral.
- Strawberries can help replenish your body’s zinc levels by providing 0.23 mg per one-cup serving.
- Dried figs are another excellent choice. One cup contains 0.82 mg of zinc.
- Tangerines, whether juiced or canned, can provide 0.53 mg of zinc for every 100-gram serving.
- Pomegranates in their raw unprocessed form contain 0.35 mg of zinc per 100-gram serving.
- Cooked plantains offer 0.12 mg of zinc per 100-gram bowl.
- Cantaloupe, which is part of the melon family, contains 0.18 mg of zinc per 100-gram serving.
Other Zinc-Rich Foods
- Spinach is a great plant source of zinc, containing 0.53 mg of zinc per 100-gram serving.
- Wheat germ can provide 0.17 mg of zinc in every 100-gram serving.
- Pumpkin and sesame seeds are excellent sources of nutrients and contain approximately 10 mg of zinc per 100 g.
- Mushrooms are another excellent source of zinc and containing 1.4 mg per 100 g are on the top of the list.
- Shellfish and seafood are one of the richest sources of zinc. Lobsters, clams, mussels, and crab are all high in this mineral, with oysters topping the charts at 76 mg per serving of six.
- Nuts are a healthy zinc-rich snack that contain approximately 5.6 mg per 100-gram serving, and one ounce of dry roasted cashews contains 1.611 mg!
- Dark chocolate is also a surprising source of zinc. One small piece of dark chocolate every day is a sweet way to increase your zinc levels. You can get 45 percent of your daily RDA with from a 100-gram serving of this delicious treat.
- Peas are another great way to obtain your daily zinc requirements. Half a cup of frozen or cooked peas offers 0.53 mg.
What You Should Know About Zinc Deficiency
Zinc is an important nutrient that your body needs to thrive. Even a mild to moderate zinc deficiency can impair the ability of your body’s organs to function. Low levels of zinc have been associated with lowered immunity. In more severe cases, zinc deficiencies have been linked to hair loss, diarrhea, impotence, eye and skin lesions, weight loss, taste abnormalities, and mental lethargy. Many of these symptoms are also side effects of other ailments so it is important to speak to your healthcare provider if you are experiencing any signs of zinc deficiency.
Bioavailability of Zinc
The bioavailability of zinc from plant-based foods is much lower compared non-vegetarian options, such as meat and fish. Red meat is known to enhance zinc absorption, whereas legumes and whole grains contain phytates that bind to zinc, so eating large amounts can inhibit zinc absorption. Therefore, if you primarily eat a plant-based diet, it’s important to increase your RDA of zinc by up to 50 percent.
Certain food preparation techniques can be used to reduce plant phytates and increase the bioavailability of zinc, such as
- Soaking beans, grains, and seeds in water for several hours before cooking them;
- Allowing beans, grains, and seeds to sit out after soaking until sprouts begin to form.
Zinc and Adrenal Fatigue
There is an actual relationship between adrenal fatigue and zinc deficiency. Zinc is a key factor in how your body stores histamines. Chronic stress can lead to adrenal fatigue. This can deplete your levels of calcium, magnesium, and zinc, thereby contributing to an increase in histamine levels. A zinc deficiency will allow high levels of histamines to be released in your body, which can produce many of the symptoms associated with allergies and make you more sensitive to allergic reactions. People suffering from Adrenal Fatigue Syndrome (AFS) often find themselves more sensitive to allergens.
Zinc deficiency can also exacerbate hormone imbalances associated with adrenal fatigue. One of the main functions of the stress-related hormone cortisol—produced by the adrenal glands—is to prevent inflammation. When zinc levels are low, your body loses its edge on fighting inflammation.
A number of other health problems exacerbated by zinc deficiency are also linked to adrenal fatigue, including:
- Estrogen dominance
- Copper overload
- Pyroluria, a genetic condition that disrupts the production of hemoglobin and other blood-related molecules
Taking zinc supplements and eating zinc-rich foods can be powerful tools during the AFS recovery process. Since all of the circuits in your body work in conjunction, something as seemingly simple as low levels of zinc can be enough to throw your entire NeuroEndoMetabolic (NEM) stress response system into disarray. A zinc deficiency, or a deficiency in any other essential nutrient for that matter, can affect the NEM stress response system, which includes both your endocrine system and metabolic circuit.
Health Risks from Excessive Zinc
Beware! As with most things, you must be knowledgeable and informed about taking supplements as there are health risks associated with overconsumption. Zinc has intrinsic stimulatory properties and both acute and chronic toxicity can occur.
Acute adverse effects of zinc often include:
- Loss of appetite
- Abdominal cramps
Consuming high levels of zinc on a daily basis has been associated with chronic issues such as
- Low copper
- Altered iron function
- Reduced immune function
- Reduced levels of high-density lipoproteins
Caution must be exerted if you are in stage 3 of adrenal fatigue since your body may not be able to properly handle supplements, including zinc. Although supplementation is crucial for AFS recovery, it’s important to allow your body the time it needs to regain enough strength so that you can actually reap the benefits of these supplements.
Zinc is suitable as a long-term supplement unless you have been advised by your healthcare practitioner to take it regularly. Improper use of zinc, including frequency, timing, and intensity, can lead to adrenal crashes. However, if you are already taking zinc supplements, you should not stop abruptly. Always gradually reduce your intake.
Before starting any nutritional supplement for adrenal fatigue, it’s important to consult with an expert to ensure you are taking the right form at the right dose for your current condition so it does not interfere with your recovery or cause any additional damage.
Zinc is not stored in the body, therefore, it’s important to consume zinc-rich foods daily. However, it’s equally important that you do not exceed the maximum RDA. That’s why, before you start any new health regime, it’s best to consult with a professional who is knowledgeable in both nutrition and AFS.
© Copyright 2016 Michael Lam, M.D. All Rights Reserved.
Dr. Lam’s Key Question
Are Zinc-Rich Foods Safe for Sufferers of AFS?
Zinc-rich foods are safe depending on what stage of Adrenal Fatigue Syndrome you have progressed to. It’s best to ask your healthcare provider about foods and supplements containing zinc since too much or too little of this essential mineral could be dangerous.