Dr Jess: As I am sitting on the sofa recovering from a horrible cold writing this, Zinc seems the perfect mineral to write on. Unfortunately today my body is proof that despite good diet, herbs and supplements, my immune system can’t overcome sleep deprivation with my son Jack!
I find zinc excellent to help shorten and lessen a cold, and also to aid immune system problems and consider it in any inflammatory disease. I encourage people to make sure they are eating zinc rich foods regularly or consider a supplement, and in certain conditions like fertility in men, growth in children and immune system diseases I always look at zinc levels.
Most people know about Vitamin C and infection, but do not know that zinc may be even more important in the modern world.
Are you getting enough of this essential nutrient in your diet? Critical for survival, learn more about Zinc below…
Zinc is nutrient essential to live, it is critical for the healthy growth and development of children (1) and is a key mineral for the functioning of our immune system (2). It is important to the activity of over 300 enzymes and 1000 transcription factors in our body, and lack of it can significantly impair brain function (3). Zinc deficiency affects up to 31% of humans globally (4). Deficiency is less common in developed countries but can be found in people who eat a diet low in red meat and high in breakfast cereals or beans (including soya) as these contain high levels of a chemical called phytate which interferes with our ability to absorb Zinc (5).
Zinc deficiency can be difficult to diagnose as standard blood tests of zinc levels are not very accurate, and even mild deficiency can cause an increased risk of infection (2)
Our immune system needs it to protect us from disease
Zinc is critical for our immune system, affecting some of our most important white blood cells called T cells (specifically TH1) and NK cells (6). Zinc also acts as an antioxidant and anti-inflammatory (3). Low zinc levels increase inflammatory chemicals in our bodies and increase inflammation, which increases our risk of many serious diseases (7).
Low levels can cause brain and mood problems
Low zinc levels are more common in Alzheimer’s patients and patients suffering from depression (8). Young children with zinc deficiency were found to have short term memory problems which improved significantly with zinc supplements (9).
For other ways to improve your child’s brain function click here
Zinc deficiency during pregnancy can cause long term developmental, behavioural and brain problems for the child (10). Zinc deficiency can induce anxiety-like and depression symptoms, and supplements have been used as treatment for major depression and shown to improve the effectiveness of medication (11).
Zinc deficiency can increase the risk of infections, asthma symptoms and allergic reactions
Taking a zinc supplement has been shown to reduce the risk of infection, particularly in the elderly (3). Zinc supplements have been shown to help reduce the severity of colds and diarrhoea in pre-school children and were most effective when in the form of chelated zinc amino acids (12). Zinc supplements improved pain and symptoms in urinary tract infections in children (13).
Low zinc is more common in allergic patients (14) and increases the number of asthma attacks in asthmatic children (15). Asthma symptoms are significantly improved by zinc supplements (16). Zinc in topical cream may reduce allergic skin reactions like latex allergies (17).
It can also affect hair growth and cause skin problems
Zinc is an important mineral for hair and commonly found to be low in patients with hair loss (18). Patients with alopecia areata (hair loss) often have low zinc levels and which also cause the disease to be more severe and last longer (19). Zinc deficiency can also lead to hypothyroidism which can cause hair loss.
For more information on natural supports for hypothyroidism click here
Zinc deficiency can cause a range of skin conditions which are often misdiagnosed as in the early stages they can resemble eczema and in the later stages produce a rash around the mouth, finger or toes or anus (20). Eczema can be improved by zinc supplements in patients with low levels (21).
Low zinc can stop wounds healing and cause macular degeneration
Chronic leg ulcers and wounds heal better with both zinc supplements and when using dressings containing zinc (22). Wounds are much slower to heal and have a higher rate of infection if the patients have low zinc levels (23). Zinc supplements daily can slow the development of AMD (age-related macular degeneration) an eye disease that can cause blindness (24).
Zinc also plays an important role in male fertility
Zinc is necessary for the healthy function of the testicles and is essential for the production of sperm (25). It should therefore be considered in men with low sperm count or with fertility issues, and zinc rich foods (see below) may be helpful in the months before conceiving a baby.
It is also important for gut health
Patients with Crohn’s disease show an improvement in their gut health (‘leaky gut’ stops) when taking zinc supplements (26). Zinc supplements also repair gut damage after methotrexate (27). Zinc fortification can alter the gut microbiome improving health (28) – to learn more about the gut microbiome click here.
It may be helpful for you to take zinc if you have a cold
A review of all the evidence (Cochrane review) recommends taking a zinc supplement at high dose of 75mg within 24 hours of the onset of a cold as it reduces the length of time of the cold and the severity of symptoms (29).
Drink too much alcohol, have AMD or diarrhoea?
Zinc deficiency is also more commonly seen in patients with bowel disease, kidney disease, liver disease, high alcohol intake and other serious long term illnesses (30).
Zinc may also benefit:
- Burning mouth syndrome – Patients with burning mouth syndrome with low zinc had a significant improvement in symptoms after taking a supplement for 6 months (31).
- Prostate health – Animal studies showed slight zinc deficiency affected prostate health and increased damage especially during physical exercise (32).
- Ageing – Zinc deficiency may increase and cause ageing of our cells due to its role in DNA (33).
- Premature babies – Babies born before term given zinc supplements showed better signs of brain development with alertness and attention. and a lower incidence of brain problems (34). Zinc supplementation reduces death and illness in preterm babies (35).
- Taste problems – Zinc deficiency is shown to reduce our sense of taste (36).
- Night blindness – Zinc deficiency is shown to reduce our ability to see at night (36).
- Crohns disease – Zinc deficiency is more common in patients with Crohn’s disease and may increase the risk of developing fistulas (37).
- Growth in children – Zinc supplementation improved growth in short male children (38).
- Sickle cell anaemia – Zinc supplementation from an early age significantly reduces complications from sickle cell anaemia (39).
- Chemotherapy side effects – A study showed children with Leukaemia improved their risk of infection and side effects of chemotherapy when taking zinc supplements (40). Low zinc levels with head and neck cancer resulted in larger and more aggressive tumours, and more complications (41).
- Down’s syndrome – Zinc deficiency is more common in patients with Down’s Syndrome and this increases the risk of infection which can be corrected by supplements (42).
- Hypothyroidism – Zinc supplements can improve T3 levels and decrease TSH levels and improve conversion from T4 (inactive form of thyroid hormone) to T3 (active form) (43).
Caution in supplementing with Zinc if:
Zinc supplementation at a reasonable dose is generally safe, however at high doses it can cause copper deficiency which can have severe side effects (44). Be cautious of zinc supplementation if you suspect you have or have been diagnosed with low copper levels. High zinc can also suppress iron levels.
TOP 5 SOURCES OF ZINC
Zinc needs to be taken daily as the body has no ability to store it. Vegetarians and those with digestive problems are more likely to be low in zinc. The RDA is 7-11mg daily and up to 25mg daily is safe to take.
Top 5 sources of Zinc in order are:
- Oysters (90.5mg per 100g)
- Pumpkin seeds (7.6mg per 100g)
- Crab (7.6mg per 100g)
- Cashew nuts – raw (5.8mg per 100g)
- Beef – mince, cooked (4.8mg per 100g)
- Chickpeas – tinned (1.5mg per 100g)
TIPS FOR GETTING MORE ZINC
Eat pumpkin seeds – One of the best food sources of zinc, pumpkin seeds are delicious roasted. They can be sprinkled on salads, porridge or over cooked vegetables. 1/2 cup provides 8.4mg.
Eat high quality grass-fed beef or lamb – Grass fed organic beef or lamb is shown to be higher in zinc (approx 6mg per 100g)
Swap peanut butter for cashew nut butter – Instead of peanut butter which can be inflammatory, swap to healthier, delicious and higher zinc cashew nut butter. 1/2 cup of cashews contain 3.8mg of zinc. Cashew nut butter also makes a great addition to smoothies and a spoonful stops hunger pangs!
Consume kefir daily – A daily cup of kefir (see here) which can be made into a healthy smoothie contains 1.4mg of zinc as a bonus to its other many health benefits!
Take a supplement – If you are concerned you are zinc deficient (seek advice if necessary from a functional medical practitioner) or to help prevent colds or infection you could take a supplement. Stick to under 25mg daily and make sure you are taking a multivitamin containing copper as well (to prevent copper deficiency). Zinc gluconate is a chelated form of zinc that is easily absorbed.