The effect of zinc on skin

As part of our series on skin and nutrition Dr Johanna Ward examines the benefits of zinc

The skin is the largest organ and has a huge physiological need for nutrition and nourishment. It exists in a state of constant renewal and repair turning over every four to six weeks. It is important that we start to take the role of nutrition and skin health seriously. The fact of the matter is that if you want healthy skin you need to feed it well and protect it from the inside out. 

Zinc is an essential mineral involved in an astounding number of cellular processes. It is required for cell division, cell growth, immunity, fertility, hormone health, blood clotting, thyroid function, eye health and wound healing. In terms of skin health and beautifying nutrition zinc is vital for cell growth, collagen formation and for wound healing.

‘Essential’ means that our bodies cannot make zinc and that we need to take it daily in our diet. With the popularity of restricted diets (vegan/vegetarian) plus issues with our collective gut health, scientists are concerned that more and more people are becoming deficient in zinc. In fact the World Health Organisation (WHO) now estimates that 30% of the global population are zinc deficient, with 75,000 deaths attributable directly to zinc deficiency each year. Modern chemical farming with its reliance on fast cropping and pesticides is at risk of farming zinc out of our soils. What this means is that the fruit and vegetables grown in these depleted soils will be less nutrient dense than before.

We only need very small amounts of zinc in our diet each day, which is why it is called a ‘trace’ mineral. Over 300 enzymatic processes in the body require zinc. Deficiency symptoms include slowed growth, low insulin levels, loss of appetite, irritability, generalised hair loss, rough and dry skin, acne, slow wound healing, poor sense of taste and smell, diarrhoea and nausea.

The body holds about 2g of zinc. Most of this zinc is found in the prostate gland, eyes, brain, liver, kidney, bones and muscles.

Groups at risk of zinc deficiency

• Vegans
• Vegetarians
• Protein restriction (especially animal protein)
• Leaky gut syndrome/malabsorption (reduces zinc absorption)
• High alcohol intake (limits absorption of zinc)
• High dietary phytates (limits bioavailability of zinc)
• Vitamin A and D deficiencies

ZINC AND SKIN HEALTH

Zinc plays an important role in skin health. It is needed for protein synthesis and wound healing and is a vital antioxidant. It also helps break down substance P, transports vitamin A from the liver and helps in the metabolism of omega 3s. Even mild deficiencies in zinc can impair collagen production, fatty acid metabolism and wound healing.

Zinc is needed for building keratin and for the formation of the skin’s structural protein – collagen. In fact collagen in the skin is produced by zinc-dependent enzymes called collagenases. Zinc is essential not only for the enzymes producing type 1 and type 3 dermal collagen but also for the cross-linking that gives collagen its durability and stability. Human studies have shown that decreased zinc results in decreased total collagen.

Skin contains a relatively high zinc content (5%), primarily found within the epidermis. Because of its abundance in the epidermis mild zinc deficiency rapidly leads to roughened skin and impaired wound healing.(1)

SKIN AND ACNE

Zinc is frequently used in the treatment and management of acne. It is known to reduce keratinocyte activity, reduce inflammatory response to bacteria and improve immunity

A study of 332 acne patients published in Dermatology compared oral zinc supplementation with oral minocyline 100mg for the treatment of acne. The zinc group received the equivalent of 30mg elemental zinc and their pimple count at 12 weeks reduced by 49.8%, compared with a 66.6% reduction in the minocycline group. Inflammation also decreased by 31.2% for the zinc group. The overall conclusion was that minocylcine was only 17% more effective for the treatment of acne than zinc.(2) Given that we live in a world where antibiotic overuse is a global health concern, the role of zinc in acne management should not be ignored.

Other studies have also found that people with acne have low levels of zinc and that simple supplementation of zinc can improve acne. Suggested doses are between 10-20mg of zinc bisglycinate or gluconate daily.

ECZEMA

Zinc deficiency is also frequently found in eczema sufferers. In one 1999 study published in Contact Dermatitis, 73% of the eczema patients involved in the study had total improvement of their eczema with a one month supplemental dose of zinc at 60 mg/day. A different study published in the Turkish Journal of Dermatology in 2009 investigated the serum levels of trace metals in patients with eczema and found that the essential minerals – namely zinc, selenium and iron – were lower in the eczema group than they were in the controls.

These findings were echoed in a 2010 study published in the journal Pediatric Allergy and Immunology that showed that low zinc and copper levels correlate with infantile eczema.(3)

INFECTIONS AND WOUND HEALING

Zinc, alone or as an adjuvant treatment, has been found to be useful in the treatment of dermatological infections owing to its modulating actions on neutrophil and macrophage functions, inflammatory cytokines and natural killer cell/phagocytic activity. It is commonly used to treat chronic leg wounds and ulcers.

Topical application of zinc has been found to be particularly helpful in wound repair. The clinical evidence relies on its importance in autodebridement, reducing superinfections and necrotic material and promotion of epithelialisation.(4)

RECOMMENDED INTAKE

Zinc’s role cannot be understated. It is extremely important that both adults and children get the recommended daily zinc intake. For women it is currently 8mg daily and 12mg for men.

Zinc-rich foods

• Oysters
• Animal protein eg. beef, liver, lamb
• Milk
• Cheese
• Eggs
• Shellfish
• Cereals
• Nuts

SUPPLEMENTS

Look for zinc bisglycinate or zinc gluconate in supplements. Zinc bisglycinate is a newer form of zinc that is evidenced to absorb well into the bloodstream.(5)

It is also worth noting that the human body absorbs zinc with the help of proteins that are rich in the amino acid cysteine. If your diet is low in cysteine your body cannot absorb zinc.

Dr Johanna Ward is a GP with a special interest in dermatology and nutrition. She is the founder of ZENii skincare, a high performance skincare and supplement brand that recognises the importance of nutrition in skin health. She won Best Journalist/Beauty Blogger at the MyFaceMyBody Awards 2017 for her educational work.

References

1. Lansdown, A.B.; Mirastschijski, U.; Stubbs, N.; Scanlon, E.; Agren, M.S. Zinc in wound healing: Theoretical, experimental, and clinical aspects. Wound Repair Regen. 2007, 15, 2–16.

2. Dermatology 2001;203:135–140 Multicenter Randomized Comparative Double-Blind Controlled Clinical Trial of the Safety and Efficacy of Zinc Gluconate versus Minocycline Hydrochloride in the Treatment of Inflammatory Acne Vulgaris

3. Paediatric Allergy and Immunology 2010: ‘Serum levels of heavy metals in childhood eczema and skin diseases: Friends or foes’

4. Kam-Lun E. Hon Shuxin Susan Wang Emily C. W. Hung Hugh S. Lam Heike H. K. Lui Chung-Mo Chow Gary K. W. Ching Tai-fai Fok Pak-Cheung Ng Ting-Fan Leung

5. Zinc in wound healing: theoretical, experimental, and clinical aspects Wound Repair Regen. 2007 Jan-Feb;15(1):2-16.