Zinc is an essential mineral, required for the formation and activity of over 100 enzymes that play a role in immune function, protein formation, wound healing, DNA synthesis, and cell division. Zinc supports normal growth and development during pregnancy, childhood, and adolescence. It is one of the minerals required to make the superoxide dismutase (SOD) enzyme, an important enzyme defence against dangerous free radical-producing carcinogens. Manifestations of zinc deficiency are rare in humans, but very low levels are linked with poor skin, nail and hair health, diarrhoea, an impaired sense of taste and smell, and poor wound healing. Many researchers have established a link between zinc deficiency and an increased cancer risk via a greater vulnerability to carcinogens, a weakened immune system and impaired DNA repair mechanisms.
Blood results from over 500 people who ordered the Cancer Risk Nutritional Profile (CRNP) have revealed that nearly 40% had zinc levels below the normal range, and only 2% had higher than normal levels. This does imply that, as a population as a whole, we need to concentrate on foods which contain a higher zinc content or even take a low-dose supplement 3 days a week (e.g. 20 mg of zinc gluconate). Be careful with higher dose supplements as they can be harmful. For example, in the Health Professionals Follow up Study (HPFS), which monitored the dietary and lifestyle patterns of 50,000 health care workers over many years, men who took supplemental zinc at levels of more than 100mg/day, or for long durations, were more than twice as likely to develop advanced prostate cancer. Taking a supplement of >40 mg per day may also prevent absorption of copper, another important essential mineral.