Acne and nutrition

While research into the relationship between nutrition and acne is both inconclusive and controversial1,2, most scientists agree that a high Glycemic Index (G.I.) and too many dairy products can exacerbate blemish-prone skin2. There is also considerable debate around the possible influence of other foods.

This article looks at some of the foods most commonly associated with acne, highlights the importance of a healthy balanced diet and makes suggestions about how you might want to alter and monitor the food you eat to see if it has a positive influence on your skin. It also explores the latest scientific thinking on this subject.

Nutritional science and common sense tell us that a healthy, balanced diet is the key to a healthy body and healthy skin, so try to enjoy a varied diet and keep a personal record (some dermatologists call this a 'skin diary') of anything you eat that you think may trigger blemishes and acne in your skin. 

If this doesn’t help you may want to try an 'elimination diet'. The best way to do this is to remove all the possible culprits (such as high G.I. foods and dairy) for at least three weeks. You should then reintroduce each food type (such as dairy, or sugar, or flour) for one day only and monitor your skin for the next two days. If you do not notice any difference continue eating that food type and try reintroducing another. This may help you to identify if particular foods exacerbate your skin.

Many scientists believe that `few studies meet high enough scientific standards to enable therapeutic recommendations to be made in practice2`. However, there have been numerous research reports that conclude that rural and non-industrialised societies have fewer instances of acne than Western populations.4 A 30-year study conducted on the Inuit population of Northern Canada in the early 1970’s showed that there were no cases of acne when the population lived and ate in their traditional way. It was only when Western foods were added to their diet that cases of acne occured.5, 6

Related reports or studies on rural Irish immigrants in the United States7, communities in Papua New Guinea and Paraguay8, and the rural areas of Kenya,9 Zambia, 10 South Africa11 and Brazil12 have also been used to support the point that the typical components of a Western diet can trigger acne.

The main components of a Western diet are hyperglycemic carbohydrates, (cow’s) milk and saturated fats and there is compelling evidence to suggest that foods with a high Glycemic Index and milk might well trigger acne.3 Both are known to stimulate androgens (male hormones) which play an important, and proven, role in the development of blemishes. You can find out more in acne and hormones.

It’s important to remember that our skin is as individual as we are − people react to different foods in different ways and what works for one person may not work for another. Here are some of the things you might like to try:

A low Glycemic Index diet

The Glycemic Index (G.I.) is a rating system for foods containing carbohydrates. It shows the impact they have on blood sugar. High G.I. carbohydrates are broken down quickly and cause a rapid increase in blood sugar. Lower G.I. carbohydrates are broken down more slowly so that blood sugar rises gradually.

Foods with a high G.I. rapidly increase blood sugar which causes our body to produce more insulin. Insulin stimulates androgens (male hormones) which, in turn, stimulates excess sebum production (seborrhea) and hyperkeritanisation (the over production of cells that leads to a hardening of skin which blocks the sebaceous glands). Seborrhea and hyperkeritanisation are key stages in the development of blemishes.

Try to replace high G.I. foods (e.g. refined foods such as white sugar and white bread, sugary foods, potatoes, white rice) with medium to low G.I. foods that will release sugar more slowly (e.g. pulses - beans and lentils - and wholegrains, some fruit and vegetables). 

High fibre foods (oats, lentils etc.) may also help to regulate insulin. A diet rich in phytoestrogens − natural, plant-based hormones found in foods such as soy, beans and lentils − may also help to keep your hormones in balance. A low G.I. diet can also be a high fat diet and so needs to be followed mindfully.

Reduce dairy intake

Milk has a relatively low G.I but is the food type most commonly implicated for acne flare-ups. In fact, a recent study that analysed the volume of research on nutrition and acne between 2004 and 2014 found that milk and milk products were the most studied area.3 That said, the data is often anecdotal and some scientists believe the comedogenic effect of dairy is yet to be proven.

If you suffer from blemishes, you may want to try reducing the amount of dairy products (milk, buttermilk, butter, yoghurt, curd, cream, cheese and ice cream) you consume to see if this has a positive affect on your skin. 

Milk is the food type most commonly implicated in acne flare-ups

For those people who do experience acne flare-ups after drinking milk or consuming dairy products, the hormone content is probably the most likely cause. Like humans, cows produce hormones during pregnancy, and these hormones have an insulin-like effect on the human system, stimulating androgens. For milk alternatives, try dairy-free products such as unsweetened soy, coconut and almond milk and steer clear of rice milk and powdered milk, both of which have relatively high G.I.s.

There are several vegan alternatives for butter (non-dairy spreads), yoghurt (soy yoghurt) cheese (tofu) and ice cream (coconut ice). Be aware that dairy products are sometimes an ingredient in other foods (e.g. mashed potato, which is often made with milk and/or butter) so you may want to avoid those too.

There’s no conclusive research on the link between chocolate and acne but chocolate still often takes the blame for blemishes2. Chocolate is high in sugar so has a high G.I. and, in addition to the sugar content, milk chocolate also − obviously − contains milk which can also trigger acne. If you can’t imagine life without chocolate, try dark chocolate. While not proven, it is possible that dark chocolate, which contains more anti-oxidants and less milk, could be less comedogenic.

Omega-3 and Omega-6 are both fatty acids essential for a healthy body. What’s particularly important is the ratio between them as this helps to modulate inflammation.13 Because humans now consume more vegetable oils (e.g. sunflower oil) the balance of Omegas in our system has changed in favour of Omega-6. To address this, scientists recommend that we consume more Omega-3 fatty acids.

A key source of Omega-3 is fish oil. Oily fish are rich in nutrients and, as such, are an important part of a healthy, balanced diet. Fish and seafood also has a low G.I. index and fish oils are known to be good for skin. Other sources of Omega-3 include walnuts, hazelnuts, chia seeds and flax seeds (though the latter need to be crushed before added to a meal to release their benefits).

Free radicals and oxidisation may well contribute to the inflammation that is present at every stage of the development of acne, and antioxidants work to combat their negative effects. Research suggests that people with acne-prone skin may also have less Vitamin A, Vitamin E - natural antioxidants - in their blood14.

Dark fruits and berries (e.g. red grapes, blueberries) are anti-oxidant rich and high in fibre which may help to regulate insulin. Watercress and avocado oil are good sources of Vitamin E and foods with a high beta-carotene content (orange foods such as pumpkin, sweet potato and carrots) are rich in Vitamin A.

Zinc is essential for healthy skin. It’s known to help reduce inflammation and work against Propionibacterium acnes, a skin bacteria closely associated with the development of blemishes. Find out more about P. acnes is the development of acne. There is also some research to suggest that acne patients may have a deficiency in zinc1. Green vegetables (especially kale and broccoli) are both antioxidant rich and a good source of zinc.

There are other steps, not related to nutrition, that you can take to help reduce blemishes and care for your skin. You can read more about these in the ideal skincare routine for blemish-prone skin, acne and stress, does exercise help acne.

If your acne persists, and continues to bother you, consult your doctor for advice on the many other measures you can try, including medical treatment options, to help reduce and remove blemishes.

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2) Acne and nutrition: a systemic review. F. Fiedler, G. Stangl, E. Fielder, K-M. Taube, 26 April 2016. Acta Derm Venerol 2017, 97: 7-9
3) Acne and nutrition: a systemic review. F. Fiedler, G. Stangl, E. Fielder, K-M. Taube, 26 April 2016. Acta Derm Venerol 2017, 97: 7-9
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11) The age distribution of common skin disorders in the Bantu of Pretoria, Transvaal. Park RG Br J Dermatol. 1968 Nov; 80(11):758-61.
12) Epidemiological survey of skin diseases in schoolchildren living in the Purus Valley (Acre State, Amazonia, Brazil). Bechelli LM, Haddad N, Pimenta WP, Pagnano PM, Melchior E Jr, Fregnan RC, Zanin LC, Arenas A Dermatologica. 1981; 163(1):78-93.
13) Diet and acne. W.P. Bowe, S.S. Joshi, A.R. Shalita, J AM Acad Dermatol. July 2010, 63(1):124-41.
14) Does the plasma level of vitamins A and E affect acne condition? Z. El-Akawi, N. Abdel-Latif, K. Abdul-Razzak. Clin Exp Dermatol. May 2006, 31(3):430-4 5 Capitanio et al from British Journal of Dermatology 2007. Ed. 157 pp1040-1085