Do you have trouble fighting off winter infections? If so, you may be low in zinc. Found in almost every cell of the body, zinc is essential to life. It is crucial to a healthy immune system and to the functioning of more than 300 enzymes that are important to regulating bodily processes. Next to iron—another essential mineral—zinc is the second most abundant trace mineral in the human body.

Among zinc’s many roles is that it maintains healthy skin and bones, supports growth and development, aids metabolic functioning, keeps hair and nails healthy, promotes wound healing, and facilitates taste and smell.

Zinc is widely distributed in foods. High zinc levels occur naturally in some foods, such as red meat and poultry, with oysters containing more zinc per serving than any other food. Other good natural sources of zinc include nuts, beans, whole grains, crustaceous seafood and dairy products such as yoghurt. Certain foods, including many breakfast cereals, are fortified with zinc. Yet, amazingly, many people are thought to be deficient in this essential mineral.

Because humans have access to only a small amount of stored zinc in the body, we need to ensure an adequate intake each day. The recommended daily intake of zinc for men and women in Australia is 12 mg, which under favourable conditions is derived from a healthy diet. Yet the zinc we absorb from food is not always enough to ensure optimal levels for healthy functioning. For instance, zinc absorption from a diet rich in plant-derived proteins is thought to be lower than from a diet high in animal protein, meaning that otherwise-well-nourished vegetarians and vegans can sometimes have less-than-optimal zinc levels. Strict vegetarians whose major staples are grains and legumes may therefore have up to a 50 per cent greater requirement for zinc than do people who eat meat, fish and poultry.

Some of the foods we eat—even those that are themselves high in zinc—can negatively affect the amount of zinc we are able to absorb. Cereals, wholegrain breads, legumes and some other foods contain phytates, which can bind zinc and inhibit its absorption by the body. However, fermentation breaks down phytates, which is why fermented sourdough breads are thought preferable ahead of wholegrain breads, and why fermented soy products such as tempeh and miso are recommended sources of plant protein for vegetarians and vegans.

A number of other factors affect zinc intake or absorption, and can even cause zinc depletion in otherwise healthy people. Factors affecting zinc intake of course include poor diet and weight-loss diets. Those affecting zinc absorption include pregnancy, taking iron and calcium supplements, and using medications such as ACE inhibitors, oral contraceptives, diuretics, histamine H2 receptor antagonists (such as Zantac) and proton-pump inhibitors (such as Somac and Nexium). Zinc depletion may be caused by excessive caffeine and/or alcohol consumption, and even by excessive exercise. Stress, acute trauma and infection can also lead to reduced zinc levels, as can gastrointestinal surgery. The elderly, the chronically ill, and people with diabetes, malabsorption syndromes or alcoholism are all at risk of zinc deficiency.

Symptoms of mild, even moderate zinc deficiency can go relatively unnoticed. They can include among other things hair loss, skin problems, diarrhoea, sleep problems and depression. In a zinc-deficient person, appetite may be reduced, and the sense of taste and smell impaired. Glucose tolerance may decrease, and wounds or ulcers may take a long time to heal. And most importantly in the colder months, coughs and colds may persist far longer than normal or expected.

With winter approaching, it is advisable to address any zinc deficiency before the cold-and-flu season sets in. A simple taste test—holding 10 ml of Ethical Nutrients Zinc Test in your mouth for 10 seconds—is all that is required to determine whether your zinc levels are low. If after a few seconds a ‘dry mineral’ or ‘furry’ taste develops, then this indicates low levels of zinc. However, if a strong and unpleasant taste is noted immediately, or if a definite taste emerges and intensifies, then this indicates relatively healthy zinc levels.

In the lead-up to winter, Southgate Pharmacy in Southbank Melbourne is offering a free zinc test to those who wish to check that their zinc levels are in the healthy range.

You can find Southgate Pharmacy on the Podium level of Southgate Shopping Centre, at the foot of the HWT and IBM towers. Or telephone us on 9699 7000 for more information about this or any other health-related matter.

Wishing you a healthy Melbourne winter!