ZINC and the IMMUNE SYSTEM
I can’t say that zinc is a go-to solution for me when I’m boosting the immune system, even though deficiencies in zinc can impact the immune system. In part, this is because I know immune boosting herbs tend to be rich in zinc as well as the many other nutrients required for healthy immune functioning.
Zinc is not the only or even the best answer for immune deficiency, by a long shot. It’s worth noting zinc is often prescribed or self-prescribed for immune deficiency even when there is no evidence of a zinc deficiency. The thing is, while correcting a zinc deficiency can help improve immune function, boosting zinc levels when they are already fine won’t do anything to improve your immune function, and may actually be counter-productive.
I’m particular opposed to this idea of using zinc as a prevention for infection when there is no proven tendency to deficiency, especially if there has been no attempt to address the underlying causes of a deficiency. This seems like classic knee-jerk reductionism-style medicine to me: use a bandaid for the symptoms of disease and make the client dependant on the bandaid (useful way to make money I suppose!) without addressing the underlying problem.
If you are low in zinc, your body will increase its absorption efficiency and it can also adapt to slightly lower than ideal intakes. When we supplement, we bypass this natural management system, and risk making our zinc levels too high, which can actually compromise immune function. It quite simply isn’t natural to bomb the body with massive doses of a nutrient that has been isolated from a whole food and it’s a good idea to avoid it when possible.
The general rule of thumb is that the deficiency signs for any nutrient are often the same or similar to the overdose signs for that nutrient. As I’ve said a million times and will continue to say: more isn’t always better. A classic nutrient overlooked when considering immune deficiency is iron, and iron levels can be compromised by zinc supplements, because zinc supplements reduce iron absorption.
What we need is balance, and the best way to achieve this with nutrients is to honour and trust the body’s innate system for keeping nutrient levels balanced in the body, by providing the body with diverse whole foods. You can read more about my philosophies on whole foods vs supplements here and here.
Zinc Deficiency Causes
As with all the nutrients, people tend to over-focus on the zinc content of a food without considering what might hinder absorption, use up zinc stores faster than necessary, or cause excessive excretion of zinc. Examples of behaviours, health problems and drugs that increase your need for zinc due to these factors include:
*Poor stomach absorption due to a lack of hydrochloric acid (eg the use of antacids or other indigestion remedies that suppress hydrochloric acid, aging, or the long term effects of stress)
*Pancreatic digestive enzyme deficiency can increase your need for zinc. Solutions can include the use of supplemental digestive enzymes or my preference: the use of herbal bitters to improve digestive function.
*Poor appetite, anorexia nervosa and alcoholism all increase our need for zinc. I suspect that zinc deficiency in childhood can result in picky eaters who don’t like vegetables!
*ACE inhibitors and corticosteroid medications can increase your urinary excretion of zinc.
*Oral contraception can decrease your blood levels of zinc.
*Zinc stores can also be depleted by the use of alcohol, beta blockers, penicillin, progesterone and steroids.
*Copper and lead toxicity can increase you need for zinc.
*Increased thyroid activity, diabetes, low blood pressure, prostate disease, schizophrenia, stress, and viral infections can all increase your need for zinc.
Zinc Deficiency Symptoms
Acne, hair loss, amnesia, brittle nails with white flecks on them, stretch marks, viral infections, learning disorders, poor immunity depression, dermatitis, loss of taste and smell, low sperm counts, moodiness, poor concentration, sleep problems, slow healing of wounds, poor growth.
Zinc deficiencies are more likely in people with diets full of refined grains (eg white bread, pasta and rice) and junks foods rich in sugar and/or fat.
Zinc Overdose Signs (caused by unnecessary ongoing supplementation)
Abdominal pain, alcohol intolerance, loss of appetite, impaired immune response, lethargy, nausea, poor growth, copper and iron deficiency, vomiting.
Whole-Food Sources of Zinc
Good natural sources can include whole grains (eg whole oats, whole wheat bread, and brown rice). seeds and seed butters (esp sunflower seeds, pumpkin seeds, poppy seeds, and sesame seeds), nuts (esp pine nuts and cashews), capsicum, legumes and tofu. Useful herbal sources include ginger, skullcap, bilberry, echinacea, astragalus, Siberian ginseng, sage, nettle leaf, dulse and elecampane.
To give you a sense for the difference between refined and whole grain zinc content, one study showed participants gained 50% more zinc from whole wheat bread compared to white bread. And this is in spite of the fact that wholegrains are rich in phytates that inhibit absorption of minerals like zinc.
Leavening of bread improves zinc absorption. Zinc absorption is also improved by fermentation and sprouting. Adding garlic to hummus or rice enhances zinc uptake from the chickpeas, tahini and grains.