Zinc is an essential mineral, and this blog is going to give you some necessary zinc knowhow. How to identify if you need it, how to take it, and what you can use it for.
While there is strong evidence to support the role of zinc for depression, immunity, acne and herpes simplex (including cold sores), it has many other uses. It may also benefit other conditions, including ADHD, sickle cell anaemia, hypothyroidism and sleep disturbances.
According to the World Health Organisation, more than 2 billion people in the world are estimated to be deficient in crucial vitamins and minerals, particularly vitamin A, iodine, iron and zinc.
Worldwide, zinc deficiency is responsible for approximately 16% of lower respiratory tract infections, 18% of malaria and 10% of diarrhoeal disease. In total, 1.4% (0.8 million) of deaths worldwide are attributable to zinc deficiency: 1.4% in males and 1.5% in females. Zinc deficiency accounts for about 2.9% of worldwide loss of healthy life years.
What is zinc, and why do we need it?
Zinc is the most abundant trace element within our cells and has powerful antioxidant and anti-inflammatory actions. It plays a vital role in the activity of over 300 enzymes in the body and is essential for catalysing chemical reactions, metabolism, protein structure, and the regulation of gene expression.
The average adult body contains 2% zinc, 90% of which is found mainly in the skeletal muscles and bones with the remainder located in most other cells of the body including the blood cells, teeth, liver, kidneys, pancreas, prostate and testes.
Zinc is also one of the most abundant trace minerals in the brain.
Zinc is an integral part of a large number of metalloenzymes. One of note is Superoxide Dismutase (SOD) which has an antioxidant effect, regularly helping to break down superoxide radicals which can be damaging if too many accumulate in your cells.
You also need zinc for essential cell growth and reproduction, immune function, wound healing, bone formation, skin, hair and nail production and your sense of taste and smell.
It can also help protect against prostatitis and is essential in sperm health and formation.
Zinc consumption in steep decline
You can easily become deficient in zinc, and your body doesn’t store it either, so you need to stock up regularly.
Apparently, in the last 60 years, our zinc consumption has declined to less than the average intake during rationing in World War II. This may partly be due to a higher rate of vegetarians and generally consuming less red meat (although you can stock up as a vegetarian).
A rise in processed foods, modern farming methods and soil depletion may also be to blame.
Causes of zinc deficiency
Severe zinc deficiency is still found in developing countries. However, mild zinc deficiency is often overlooked. It’s more common and can be hard to diagnose as it regularly occurs with other micronutrient deficiencies, including iron.
An inadequate diet can cause a deficiency. Another cause is malabsorption due to GI conditions including Crohn’s disease, short bowel syndrome, ulcerative colitis, chronic diarrhoea and gastrointestinal viruses.
Zinc may also be lost due to excessive excretion through the urine or pancreatic secretions for reasons such as chronic liver, kidney or pancreatic disease including diabetes, alcoholism and the overuse of diuretics.
Sickle cell disease, pregnancy and breastfeeding, too much iron, copper or calcium in the body, starvation or eating too many foods with a high phytate content can inhibit zinc absorption.
The elderly can be more prone to zinc deficiency, especially if they are in care. Those being fed intravenously for long periods can also have insufficient levels.
It’s important to note that modern and intensive farming methods deplete the nutrients and minerals in the soil. This directly impacts mineral levels in the crops we eat.
Added to which, processing methods which strip the zinc content from cereal grains can also contribute to a deficiency. Eating organic may help to boost your levels as farming practices encourage more fertile soil with increased nutrients.
Zinc deficiency signs and symptoms
Deficiency symptoms vary depending on how insufficient your levels are.
More severe symptoms can include sexual and skeletal immaturity, slowing of growth and development, neuropsychiatric disorders, alopecia, chronic diarrhoea, dermatitis, vulnerability to infections and loss of appetite.
Deficiency can also result in paronychia (an infection of the skin in the nail fold), anorexia, weight loss, macular degeneration, impaired sense of taste and smell, poor wound healing, acne, learning disorders, mild anaemia, reproductive disorders, infertility and depression.
Milder symptoms can be dry or rough skin, dull hair, white spots on and brittle fingernails, mood swings, reduced adaptation to darkness, tinnitus, stretch marks, and poor memory.
Babies from mothers with zinc deficiency during pregnancy may be at increased risk for congenital disabilities and low birth weight. At the same time, those from poor, urban environments can also have an added risk of premature birth.
Worried your zinc is low? Take a zinc taste test
One way to get an indication of whether your zinc is low is to take a zinc taste test. It’s a simple non-invasive test that you can easily buy online. You add a solution containing zinc to water and drink it.
The liquid relies on your body having enough zinc to detect the mineral within the drink. Depending on the taste, it will give you an idea of where your zinc levels lie.
You need more zinc if:
• You have an inadequate dietary intake due to poor eating habits, fad, weight loss, or exclusion diets, or a restrictive vegetarian or vegan diet. You may also be deficient if you are elderly with a reduced appetite, finding it harder to eat balanced and varied foods.
• You don’t absorb zinc effectively enough due to poor gut health and digestive conditions including Crohn’s, coeliac disease or short bowel syndrome, alcoholic cirrhosis or pancreatic insufficiency. Acrodermatitis enteropathica, a rare, inborn, autosomal recessive disease is a disorder of primary zinc malabsorption.
• You are at risk of zinc deficiency if you are pregnant or breastfeeding, a growing child or teenager, an older breastfeeding child. Also, if you are an alcoholic, are anorexic, have chronic renal disease or sickle cell anaemia, are older than 65, have persistent diarrhoea, or are being fed intravenously. Premature and low birth weight infants are also at risk.
What is zinc good for?
Zinc has been used therapeutically for hormone imbalance, ADHD, acne, herpes simplex virus, general immune function, sickle cell anaemia, diarrhoea, Wilson’s disease, the common cold, age-related macular degeneration and hypothyroidism.
Research continues for the use of zinc in various blood disorders, cancer, appetite stimulation, Celiac disease, chemotherapy side effects, closed head injuries, cognitive disorders and function, diabetes and HIV/AIDS.
We need zinc for efficient cell signalling and immune cell function. So, if you find that you are getting recurring bouts of illness such as coughs, colds or flu, you may need to up your zinc levels.
For example, one meta-analysis found that supplementing with zinc lozenges between 70mg and 100mg daily, shortened the common cold by 33%. Evidence suggests that zinc will be most effective when taken within 24 hours after cold symptoms start.
Low zinc status is relatively common in the elderly and can contribute to lowered immunity. Research for zinc supplementation to improve immune function in the ageing is ongoing, and while mixed, there have been some positive results.
One study found that elderly care home residents with insufficient zinc levels are more susceptible to pneumonia. Other studies have also found that zinc supplementation in the elderly can have a positive effect on the action of T-cells (white blood cells key to the immune response).
Another study found that supplementing with 25mg of zinc daily over three months in people over 65 years of age improved helper T-cell and cytotoxic T-cell function, improving their cell-mediated response and immunity.
We know that zinc improves immunity, and this is part of the reason why it helps to accelerate wound healing.
It also helps to stimulate collagen production and has an anti-inflammatory action which encourages effective healing. Studies show that zinc supplementation can speed up the healing of skin ulcers.
It plays a vital role in regulating every phase from membrane repair, oxidative stress, coagulation, inflammation and immune defence, to tissue repair, the formation of new blood vessels and scar formation.
Depression, mood changes and brain function
Zinc is one of the most abundant trace minerals in the brain, and low levels are linked to depression.
Essentially, zinc acts as a neuronal messenger and is vital for healthy brain function, memory and learning, regulating mood and preventing conditions like depression, hyper-anxiety and other mood disorders.
Zinc helps to break down food during digestion, and low levels can also contribute to poor gut health. Zinc deficiency can slow everything down, causing food to decay in the digestive tract, bringing symptoms like constipation along with it, as well as a reduced appetite.
Your gut and mental health have a very close, symbiotic relationship, so this is another way that depleted zinc levels can alter your mood.
Zinc is also exceptionally good at aiding the digestion of proteins. We need proteins for keeping feel-good neurotransmitters like serotonin and dopamine working in the brain. So if you can’t digest proteins effectively, your cognitive function may suffer.
There appears to be a correlation between low zinc levels and acne. The amount of zinc depletion may reflect on the severity and type of lesions for people with acne vulgaris.
Your body needs to use zinc to calm inflammation of the nodules and cysts, so if you are already depleted, this could make matters worse.
Either way, if you suffer from acne, you could benefit from supplementing with zinc due to its anti-inflammatory benefits, it may also help to prevent bacterial growth and reduce oil production.
Current research supports the topical application of zinc sulfate for the treatment of genital herpes.
Type 2 diabetes
Zinc and insulin (the primary hormone linked to blood sugar balance) are closely related. Zinc is released with insulin when blood glucose concentrations increase. It also stimulates glucose uptake and metabolism by insulin-sensitive tissues.
Research is mixed, but there have been some positive studies. The Nurses Health Study tracked 82,297 American nurses over 24 years.
The analysis showed that there was an 8% lower risk of diabetes in those with the highest dietary zinc intake (on average 11.8mg a day versus 4.9mg a day).
A similar Australian study following 8,921 women over six years found a 50% lower risk of diabetes in those with a higher zinc intake.
There are several studies linking zinc supplementation to improved glucose handling in people with established diabetes but less showing an effect on pre-diabetics.
A 2016 study on 55 Bangladeshi pre-diabetic patients gave half the group 30mg of zinc daily, and the rest took a placebo. After six months, the zinc group had significantly improved fasting blood glucose concentration compared to the placebo group. Their beta-cell function, insulin sensitivity and insulin resistance all showed a statistically significant improvement as well.
Low zinc intake appears to be linked to lower bone mass. Taking a zinc supplement in combination with copper, manganese and calcium might also decrease bone loss in women who have passed menopause.
Dietary sources of zinc
It’s easier to obtain zinc from animal sources, but it’s also present in plant-based foods. In pure zinc terms, eating a balanced and varied diet including some organic grass-fed lean red meat, fruit, vegetables, pulses and cereal grains should provide you with enough zinc.
Zinc is most prevalent in high protein foods with oysters being the most abundant source – they have as much as 148.7 mg of zinc per 100g serving. Other foods include red meat, poultry, liver, heart and other shellfish.
Leafy and root vegetables can be a good source, but it depends on the soil in which they are grown. Legumes and whole grains, pulses, nuts and seeds such as pumpkin and sunflower, fresh root ginger and some dairy products including yogurt, milk, cheese and eggs also contain zinc. It is also found in fortified breakfast cereal.
Foods that inhibit zinc absorption
Foods with a high phytate content can inhibit zinc absorption. Phosphorus-rich phytic acid is found in grains, beans, legumes and nuts (which are also plant sources of zinc).
While phytates aren’t all bad, they also inhibit our absorption of other minerals such as magnesium, calcium, phosphorus, copper and iron.
Phytates can also hinder certain digestive enzymes, making it harder for us to break down and utilize our food, while potentially causing gastrointestinal disturbances.
If you get bloated after eating beans, or quinoa, for example, it could be the phytic acid that is the problem.
You can reduce the phytate level in these foods by soaking them for up to 24 hours before cooking (some grains like buckwheat and quinoa can soak for a shorter amount of time).
You need an acidic agent like apple cider vinegar and hot water to help break the phytates down, plus a warm spot in the kitchen. There’s plenty of information online on how to do this.
Things to consider when taking a zinc supplement
It’s essential to get the balance right, as zinc and copper can decrease the absorption of each other in the GI tract.
Excess iron, copper and calcium may inhibit the absorption of zinc. If you’re taking both an iron and zinc supplement, they should be taken apart from each other to avoid interfering with their activity.
Also, be aware of drug interactions. For example, ACE inhibitors may decrease the levels of zinc in the blood.
The diuretic called Amiloride (Midamor) may increase zinc in the blood, and zinc supplements are not advised while taking it.
Excess zinc can inhibit the absorption of two different types of antibiotics known as Tetracyclines and Quinolones. It can also inhibit the absorption of nonsteroidal anti-inflammatory drugs (NSAIDS).
The list goes on, so always check with your doctor before supplementing.
The daily RNI (Reference Nutrient Intake) for zinc
These are the current Reference Nutrient Intakes per person per day for Zinc:
Infants up to 7 months: 4mg
Children aged 7 months to 3 years: 5mg
Children aged 4 to 6 years: 6.5mg
Children aged 7 to 10 years: 7mg
Males aged 11 to 14 years: 9mg
Males aged 15 to 50+ years: 9.5mg
Females aged 11 to 14 years: 9mg
Females aged 15 to 50+: 7mg
Pregnant females aged 16 to 50 years: 7 mg
The Department of Health advises that zinc supplements should not exceed 25 mg a day.
The Tolerable Upper Intake for zinc is 40mg daily. This is for ages 19 and over and applies to zinc intake from food and supplements.
However, always check with a nutritional therapist, naturopath or another health professional before taking a higher dose.
Zinc has profound antioxidant and anti-inflammatory effects, not to mention the epic amount of different jobs it’s essential for in your body. It can be used therapeutically, alongside other necessary treatments, for several conditions, and there is much continuing and encouraging research.
Amongst other things, it activates your immune system and reduces oxidative stress and inflammation. It can also shorten the duration of a cold and speed wound healing. Positive research has shown that the elderly with depleted zinc levels can benefit from supplementation, boosting T-cell function, the white blood cells key to the immune response.
Researchers have also linked normal zinc levels with a reduced risk of pneumonia in the elderly. Being one of the most abundant trace minerals in the brain, low levels of zinc can contribute to low mood, depression and reduced cognitive function. Zinc may also help improve acne, cold sores, and strengthen bones while helping to improve insulin sensitivity in type 2 diabetics and pre-diabetics.
If you’re worried your zinc is low, you can experiment with a zinc taste test which can give you an indication of where your levels lie. It’s always best to get your nutrients, including zinc, from food but you can supplement if you feel it’s warranted. However, be aware of your dosage and consult a health professional if you go above the daily RNI. Always ask your doctor before taking zinc if you have a chronic condition and are taking medication.
Written by Rebecca Rychlik-Cunning, Nutritional Therapist andHomeopath. Follow Rebecca on Instagram, Facebook and Medium, @rebeccabitesback.
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Studies show that zinc supplementation can speed up the healing of skin ulcers.