Zinc is very busy in your brain. It is needed by the hippocampus, which is the central train station for relaying messages to and from the ceaselessly busy nervous system, endocrine system and the rest of your body. Without zinc, people do poorly in both memory and cognitive tests and are more likely to suffer mood disorders. Zinc activates brain centres that process data from taste and smell sensors and thus influences appetite. People with anorexia and bulimia usually suffer from low levels, which distort their appetites further. Athletes and those who perspire profusely lose this mineral through fluid loss; as do those with diarrhea, vomiting or after gastrointestinal surgery.

Of 16 key nutrients studied by Tufts University, more children were deficient in the essential trace mineral zinc than any other. 50% of poor children and 30% of non-poor children had markedly low levels. Unlike the need for nappies though, this isn’t something you are likely to grow out of.

Pregnant women with insufficient levels have three times the risk of premature delivery, and twice the risk of a low birth weight baby. Such a heritage sharply increases an infant’s later likelihood of diabetes and cardiovascular disease. If your first environment is one of deprivation then you grow up prone to eating quickly and excessively – especially when under stress. Insufficient zinc impairs fetal brain and spine development; lowers absorption of folic acid, critical to building red blood cells and preventing anemia.

Think Zinc to Keep Hormones in the Pink

The modern world is high in many forms of the female hormone estrogen and in excess this promotes weight gain, mental and physical fatigue, and abnormal cell growth such as cancer. Chemicals (see website TIPS article) such as used agriculturally; in plastics; standard building materials, toiletries and cleaning agents act as xenoestrogens or toxic hormone mimics. Hormones and hormone-influencing medications are also used directly by people, and as treatments for dairy and meat animals.

For men to stay manly, zinc may be their most vital nutrient player. Inadequate zinc prevents the brain’s office manager, the pituitary, from releasing hormones (LH and FSH) which stimulate testosterone production. Zinc increases sperm count, motility and thus fertility. Too much circulating estrogen – whether self-produced or from outside sources – increases levels of aromatase. This enzyme converts testosterone into a dangerous form called dihydrotestosterone. DHT leads to abnormal growth in the prostate: a walnut-sized organ beneath the bladder which surrounds the urethra through which urine flows. Even without malignancy any excess growth causes disturbed urgency, frequency, straining and other urinary problems that can affect sleep and social lives. Zinc can come to the rescue, by both inhibiting aromatase and helping the liver to break down and eliminate excess estrogen (TIPS: Male Health).

In contrast, Alcohol (TIPS) increases estrogen levels and lowers zinc, forcing it out through urine. Body fat is a storage site for aromatase; fat increases estrogen which in turn increases fat storage. Being over-fat and under-muscled is like creating an extra estrogen-producing, inflammatory organ. Many thin-to normal looking but sedentary people have more fat (visceral, hidden and dangerous) than a sumo wrestler.

Your 30 Trillion Cells Need Good Instructions

Women with high estrogen levels – compared to other needed sex hormones – are prone to fibroids, endometriosis, menopausal and premenstrual problems. Zinc regulates the secretion of such hormonal messengers as: women’s feel-good progesterone; testosterone for libido; endorphins that act as natural pain-killers; and the synthesis and action of insulin needed to deliver blood sugar into eager cells – the chief fuel for your brain and muscles. Zinc can independently increase glucose transport into cells. For instance in the Skin (TIPS) this aids vigorous growth and renewal; hence acne has been termed ‘skin diabetes’. If zinc levels are low, insulin response decreases and blood sugar becomes difficult to stabilise (TIPS: Weight). Your metabolic rate – how efficiently you create essential building materials, and burn food for fuel or store it as fat – will drop with low zinc, as will Thyroid function (TIPS).

For everyone, zinc is essential for optimal – not runaway – cell division and to preserve the integrity of DNA for accurate cell instructions. Inside each of your cells is a central nucleus containing the chromosomes gifted equally by your Mum and Dad. These are made of ribbons of DNA containing tens of thousands of genes. The cell has to decide which of these genetic instructions to read (a process called gene transcription). With insufficient zinc important instructions get misread or ignored.

Check Your Insides By Your Outsides

Such relayed data ensures healthy skin, nails, and hair – good gauges of what is happening invisibly within. Zinc is needed for such connective tissue formation (which includes Bones – TIPS), and for the transportation of vitamin A from the liver to all these areas to protect them from damage. No repair work or growth can be accomplished without zinc. It is used medically as an anti-inflammatory for blisters, wounds, burns, skin ulcers, bedsores, and gum disease. As an antioxidant it works hard to quell vandalising free radicals associated with trauma, to stabilise membranes, and heal inside and out.

High levels of zinc are needed in the retina; for good vision at night; to help prevent cloudy cataracts and the full or partial blindness of macular degeneration increasingly common with age. Vegetarians may need 50% more zinc due to poorer absorption from plant foods. Zinc is often paired with vitamin A to treat Eye (TIPS), skin, immune and respiratory problems. Vitamin A requires zinc for efficient transportation around the body and then to be effectively mobilised when it reaches its needed destination.

Even modest deficiencies will depress immune function (see HEALTH STORE for my report). Zinc is essential for developing and activating T-lymphocytes, macrophages, and B-cells: white blood cells that must have zinc to recognise and fight infection. It is also busy producing over 200 enzymes including your antioxidant superhero superoxide dismutase, which protects cells and their factory-like energy production from free radical vandalism.

Indicators for Increasing Your Zinc:

• Weak nails with tiny white spots (cloudy blotches may indicate low calcium).

• Dandruff; thin, dull hair; early greying; hair loss.

• Poor skin and wound repair; acne, eczema, psoriasis.

• Blood sugar imbalances (mental/physical fatigue; overweight or thin with low muscle mass/strength). See HEALTH STORE for my report on Vitality)

• Impaired immunity with frequent infections or limited recovery from past trauma, surgery or illness.

• High estrogen levels (evident with prostate, PMS and menopausal problems; fibroids, endometriosis, hormone-sensitive cancers; some mood disorders). See Sex Hormones.

• Suboptimal liver function (TIPS …Love Your Liver); impaired digestion and elimination; high iron or copper (which use the same gut absorption site), high vitamin C or heavy metals (such as lead, mercury, aluminium, or cadmium from smoking).

• Fluid loss through profuse sweating, athletics, loose bowel function (TIPS: Digestion), or vomiting.

• Impaired sense of taste, smell, appetite (common with eating disorders); eye health especially night vision, cataracts, macular degeneration.

• Poor sperm count or motility; premature or low weight at birth; physically or mentally underdeveloped infants; poor growth in childhood (TIPS: Fertility).

• Regular or high alcohol intake; use of oral contraceptives, copper intrauterine device, antibiotics, antacids, blood pressure lowering Medications (TIPS).

Food processing such as canning, and cooking foods in water that is later discarded will markedly reduce the zinc content. Similar to iron, zinc is 3-4 times more bioavailable or absorbable from animal rather than plant foods. Keep supplemental dosages to no more than 30 mg daily. Common to Vitamin and mineral (TIPS) supplements, an excess can create similar symptoms as a deficiency. Toxicity can lead to a bitter metallic taste (also true of heavy metals), with diarrhea, impaired immunity and gastrointestinal function. Too much zinc will decrease absorption of copper and calcium.

Some health practitioners offer a ‘zinc taste test’ as an assessment tool. Litmus paper with zinc sulphate is placed on the tongue. The theory is if the taste is unpleasant there are adequate levels; if tasteless you need zinc. However smoking, drinking or eating within one hour before will compromise accuracy. Some people have more taste buds than others and are termed ‘high tasters’. They will tend to have an exaggerated response regardless, which can nullify any association. Your symptoms overall are better at telling your story.

Top dietary sources* (soil dependent) in order are: oysters, liver and red meat, poultry, nuts and seeds (especially pumpkin, almonds, peanuts and sesame), shellfish, mushrooms, legumes, and wholegrains.

*NZ and APJCN Food Composition Tables; USDA Nutrient Database
Dependent on season, soil, variety, style of preparation