In a word: none.
As a naturopath and lecturer I often hear enthusiastic advocates of a dairy and gluten-free diet to treat acne; “It worked for me/my friend/sister..” etc. That’s great if it worked for them and there is definitely a sound rationale behind eliminating dairy to minimise hormonal acne but there is no current evidence that gluten causes or exacerbates acne.
Dairy milk contains high levels of androgens and insulin-like growth factor (IGF-1) which can exacerbate sebum production, leading to the formation of comedones which are pores or hair follicles filled with a mixture of keratin (dead skin cells), sebum and bacteria. Propionibacterium acnes is a bacteria that lives on the skin’s epidermis and feeds on sebum, producing propionic acid, a short-chain fatty acid. When hair follicles or pores become blocked with keratin and sebum, the conditions become anaerobic and P. acnes multiplies, leading to infection and inflammation. If this builds up under skin cells it forms a white head (acne vulgaris). If it happens in an open pore the sebum reacts to oxygen and turns dark (black heads). Opportunistic bacteria such as Staphylococcus species can then join the party and lead to a more serious infection.
However, going gluten-free would prohibit possibly significant benefits from using a promising plant component for the treatment of acne. Azelaic acid from barley (and wheat) kills P. acnes, slows down keratin production and decreases inflammation associated with acne rosacea and cystic acne, especially when used topically. ¹
Black and purple barley also contain anthocyanins which counteract sun and age-related skin damage. If you can find these ancient grains, grab them and add them to your anti-ageing diet.
Barley, importantly, is also low GI. A low GI diet does help with acne control as it decreases insulin secretion which has the secondary benefit of decreasing androgen and IGF-1 synthesis. Like oats, barley is also a good source of zinc and B vitamins which improve skin health and healing. So there are several low GI grains which contain gluten but are beneficial for acne. Unless you have coeliac disease there is no reason to avoid them in treating acne.
However, if you need or prefer not to eat barley and oats, you can still get the benefits topically (directly on the skin). Try this DIY acne face mask to counteract inflammation and infection and draw the comedones out gently:
DIY ACNE FACE MASK
1 tsp barley flour
1 tsp oat flour
½ tsp slippery elm powder
1 tsp zeolite or bentonite clay
1 tsp manuka honey
Rosewater or cooled lavender tea
Mix to a paste with rosewater/tea. Spread gently over the affected area and leave on for 10-20 minutes. (Practice your relaxation breathing techniques while you wait!) Rinse off with tepid water and repeat daily until acne is clearing.
Here is another DIY recipe for sun-damaged skin and acne rosacea:
DIY SUN DAMAGE FACE MASK
1 tsp black barley flour (or plain as it is tricky to find)
2 tsp oat flour
1 Tbsp. blended blueberries or 1tsp acai berry powder
1 tsp manuka honey
Rosewater or cooled liquorice tea
Mix to a paste with rosewater/tea as above and leave on for 10-20 minutes. Liquorice contains glabridin, a plant constituent that inhibits melanin synthesis (the pigment that darkens skin) and has traditionally been used in skin-lightening creams for this purpose. ²
Liquorice is also an excellent anti-inflammatory herb useful for acne rosacea. Blueberries and acai berries fortify the antioxidant value of this DIY skin mask.
If you’re not much into kitchen cosmetics, don’t worry! Third Stone Botanical’s ever-popular Almond Rose Cleansing Scrub contains all of the dry ingredients in the DIY acne recipe with ground organic almonds, rose petals, green tea and lavender flowers. Just add water and some honey to make a wonderful acne treatment mask. Too easy!
- Iraji F, Sadeghinia A, Shahmoradi Z, Siadat AH, Jooya A. Efficacy of topical azelaic acid gel in the treatment of mild-moderate acne vulgaris. Indian J Dermatol Venereol Leprol. 2007; 73:94-6.
- Seino H, Arai Y, Nagao N, Ozawa N, Hamada K. Efficient Percutaneous Delivery of the Antimelanogenic Agent Glabridin Using Cationic Amphiphilic Chitosan Micelles. PLoS ONE. 2016; 11(10):e0164061.