How to eat your way to healthy skin
Although some skin care companies would like us to believe that beautiful skin comes from regularly applying their expensive creams and potions, most people would be reassured to know that beautiful skin is really another way of saying ‘healthy skin’. In fact our choice of skin care plays only a small part in the health of our skin. Our skin is an outward manifestation of the health of our bodies, and as our body’s largest organ, it tells quite a story. The choices we make about nutrition, the quality of the air we breathe and the water we drink, our exposure to alcohol and other drugs, UV light and stress, how well we exercise, the efficiency with which our bodies eliminate toxins and neutralise free radicals, and yes, our choice of skin care, are all quite literally written into our skin’s DNA. We have described in a previous blog how our certified organic skin care can help slow your skin’s ageing (Read it here). Here we look at the latest science behind how our diet affects the health of our skin, and what foods will keep it looking its healthiest, no matter your age.
How does diet affect acne?
In western cultures, acne affects around 85% of adolescents and young adults at some stage of their lives, whereas it is rarely seen in indigenous communities living a non-western lifestyle (1). We have written a blog about the latest understanding of acne here. For a long time diet has been thought to be a significant factor in the incidence of acne. Recently, a strong association was found between the severity of acne and high glycemic diets, those which are dominated by foods that cause a marked rise in blood sugar. This finding correlates with the fact that high glycemic diets are very common in the west, and rare in indigenous cultures. There was a weaker link between the regular consumption of dairy products and the severity of acne, while a higher intake of omega-3 fatty acids, found in oily fish and some seeds and nuts, may have the effect of reducing the severity acne (2).
Which foods age your skin?
The loss of elasticity and firmness of the skin we associate with ageing is caused by changes to the structure of the collagen and elastin fibres in the dermis, the deep layer of the skin. It is also accompanied by a reduction in the amount of glycosaminoglycans, like hyaluronic acid, that hold water in the skin and keep it plump. The changes to collagen and elastin are due to ‘glycation’ a process where cross-links are formed by glucose and fructose within the collagen and elastin molecules (summarised in 3). Glycation occurs not just in the skin, but throughout our bodies, and is thought to contribute to a range of chronic degenerative diseases associated with ageing. Unfortunately, our bodies are unable to repair these cross-linkages, and so prevention is key. High sugar foods and, once again, a high glycemic diet, contribute to glycation. In addition, foods prepared by grilling, frying and roasting that result in browning, known as the Maillard reaction, particularly animal-derived foods, are rich in glycation end-products and contribute to the damage to collagen and elastin throughout our bodies (summarised in 4)
The good news is that some foods are able to inhibit glycation, and this ability seems to correlate with their antioxidant activity. Therefore, foods rich in antioxidants like the polyphenols, vitamins C and E and the carotenoids, which protect against free radicals and reduce inflammation in the body, may also protect against glycation (summarised in 5). These nutrients are abundant in fruit, vegetables, herbs and spices, particularly when they are minimally cooked and unprocessed.
Other nutrients are also important. In a study looking at the influence of diet on the appearance of skin ageing in women aged 40-70 in the USA, it was found that higher intakes of vitamin C and linoleic acid, an omega-6 essential fatty acid, and lower consumption of fats and carbohydrates were associated with younger-looking skin (6).
Some foods can help protect against UV-induced skin damage (photoageing).
UV light damages our skin in three ways: it increases the rate of production of oxidants, which can then damage DNA and proteins; it activates matrix metalloproteinases, enzymes that degrade collagen and elastin; and finally it inhibits production of new collagen. The end result is thinner skin with reduced collagen and elastin, and a loss of the hydrating glycosaminoglycans. UV-induced skin damage is known as ‘extrinsic’ ageing, as it accelerates the appearance of aged skin, although the molecular process is different to ageing in the absence of UV damage.
Some degree of protection from UV light is provided by the presence of abundant antioxidants in the skin, particularly vitamins E and C, which work together to protect cells from free radical damage. Vitamin E is fat soluble, and found in vegetable oils, nuts, seeds and avocados and some types of meat. Vitamin C is water soluble, and abundant in for example parsley, capsicum, rosehip, and various fruits including citrus.
The carotenoids are the other important antioxidants derived from plants, forming pigments that give a yellow, orange or red colour to foods, including for example carrots, tomatoes, sweet potatoes and watermelon. Both lycopene and β-carotene, two of the most abundant carotenoids in food, can reduce the amount of UV-induced redness in the skin, probably through their antioxidant effects (7).
Omega-3 fatty acids from fish oil also seem to play a protective role against sun damage. UV-induced inflammation was reduced in patients given long-term fish oil supplements (8).
Studies looking at the incidence of non melanoma skin cancer found that taking antioxidant supplements of vitamin C, vitamin E, beta-carotene, selenium, and zinc did not reduce the risk of these cancers. However when looking at consumption of whole foods rich in antioxidants, particularly diets rich in fruit and vegetables, there was a reduced risk of squamous cell carcinoma by over 50%. In contrast, consumption of meat and high fat diets increased the risk (summarised in 9).
The health of our skin is really an indicator of the health of the rest of our bodies. Food that is good for our skin is, as a general rule, good for the rest of our bodies too. No matter what health condition you look at, whether it is ageing, cancer risk, degenerative disease, inflammatory diseases or acne, the advice is generally the same - eat plenty of antioxidant-rich fruit and vegetables, reduce consumption of meat and dairy, eat plenty of omega-3 fatty acids, avoid sugar and other high glycemic foods, don’t overcook your food, and eat it fresh where possible.
We use the same principles with our certified organic skin care, so that it delivers biocompatible nutrients that will complement what your healthy diet delivers from the inside. We recommend you delete the preservatives, emulsifiers and other synthetic ingredients from your skin care in the same way you would eliminate them from your food. We believe that using certified organic skin care made using only fresh, whole ingredients that are naturally rich in antioxidants, essential fatty acids and anti-inflammatory phytonutrients, is the best way to optimise the benefits of your healthy diet.
Cordain, L. et al. (2002) Acne vulgaris: a disease of Western civilization. J Arch Dermatol. 138:1584-90.
Burris J. et al (2013). Acne: the role of medical nutrition therapy. J Acad Nutr Diet. 113:416-30
Rajani, K. and Desai, S. P. (2014) The Role of Dietary Intervention in Skin Disease J Clin Aesthet Dermatol. 2014 7: 46–51.
Uribarri, J. et al (2010) Advanced Glycation End Products in Foods and a Practical Guide to Their Reduction in the Diet J Am Diet Assoc. 110: 911–16
Sadowska-Bartosz, I. and Bartosz, G. (2015) Prevention of Protein Glycation by Natural Compounds. Molecules 20: 3309-3334
Cosgrove, MC et al. (2007) Dietary nutrient intakes and skin-aging appearance among middle-aged American women Am J Clin Nutr. 86:1225-31.
Sies, H. et al. (2004) Carotenoids and UV protection. Photochem Photobiol Sci.3:749-52.
Rhodes LE et al (1995) Dietary fish oil reduces basal and ultraviolet B-generated PGE2 levels in skin and increases the threshold to provocation of polymorphic light eruption. J Invest Dermatol. 105:532-5.
Katta, R. and Desai, S.P. (2014) Diet and Dermatology: The Role of Dietary Intervention in Skin Disease J Clin Aesthet Dermatol. 7: 46–51.