In 1869, it was reported for the first time that zinc was essential for the growth of microorganisms, but it was not until the early 1960s that it was considered crucial for human health.
The current estimate by the World Health Organisation (WHO) is that over 2 billion people may be affected by zinc deficiency. However, many more experience zinc insufficiency due to inadequate dietary intake, digestive system disorders leading to poor absorption, alcoholism, genetics, old age, pregnancy and breastfeeding and athletes or individuals who sweat frequently.
Zinc is needed in the body for over 300 enzyme reactions and plays a vital role in DNA protection, reproduction, hormone synthesis, immunity, and gut and brain health, to name but a few! Symptoms of zinc insufficiency include diarrhoea, decreased immunity, hair loss, impaired sense of smell or taste, dry or rough skin and impaired wound healing. Zinc can help manage inflammation, reduce oxidative stress, inhibit histamine and allergic response, improve gut permeability, improve sleep quality, support skin health, maintain healthy neurological and cognitive functions and promote fertility. It's definitely something to keep at an optimal level.
The best food source of zinc are oysters, which contain exceptionally high amounts. Six medium oysters provide 33mg of zinc, which is 300% of the daily requirement for men and 412.5% for women! Other shellfish, such as crab and mussels, together with beef, lamb and pork, are also good sources.
Legumes such as chickpeas, lentils and beans all contain high amounts of zinc but also contain substances called phytates, which are anti-nutrients that reduce zinc absorption. Heating, sprouting, soaking or fermenting legumes can increase bioavailability. Other good plant sources include pumpkin and sesame seeds together with pine nuts, cashews and almonds.
Zinc is best obtained from food, and supplements should only be used on a short or medium-term basis as higher levels of zinc can reduce levels of other trace minerals in the body, such as copper and iron. Conversely, minerals such as calcium and magnesium can affect zinc absorption.
A simple zinc taste test is available to assess an individual's zinc status, and a nutritional therapy appointment can provide guidance on ways to improve zinc through diet and any supplementation, if appropriate.