You Are What You Eat: Skin and Diet

Culinary medicine (and just cooking and eating in general) are passions of mine outside of the field of aesthetic medicine. I actually firmly believe that aesthetics and wellness go hand-in-hand - both feed into a general philosophy self-care for ourselves, which is essential to both our physical and mental health.

In a nutshell: I love food and I love celebrating, enjoying, and eating it.

I am not a proponent of diets, cutting out any food groups or restricting ourselves, following fads, or consuming anything that is over-processed. I think a huge part of cultivating a healthy relationship with food is understanding some basics about nutrition, having a balanced and well-rounded diet, and also (absolutely) indulging in the foods we love especially if we’re able to make them ourselves. I’m never happier than when I’m able to take several hours with a glass of wine and cook a massive, gorgeous recipe.

The topic of culinary medicine is a massive one and probably beyond the scope of The Aesthetics Edit. However, something that I have seen come up often is the question of diet and skin.

There is of course a connection - our skin is a reflection of our overall health and there is no doubt that our diets play a massive role in our overall health. However, is there any truth to the claim that you can “eat for your skin?” We touched on this idea in our article about collagen supplementation, and we thought we’d take the opportunity to expand on it.

So how much of your diet actually affects your skin health?

The Headline

I’m going to skip ahead and say that while there is definitely a relationship, showing causality is complicated. A good, balanced, and nutritious diet will be beneficial to your skin, and we are going to showcase some of the foods that are advocated and explore why. From an evolutionary point of view, it makes sense that the building blocks needed to have and maintain good skin can be found in a well-rounded diet. But if you have a skin issue, a diet will not cure you. In the same vein, I’m very wary of anyone who tells you you have to cut out a certain food from your diet as a quick fix for a skin issue, as this is usually backed by very little evidence.

I do want to say that in general I do not advocate supplements – they are usually just clever marketing and a waste of your money. This includes the latest trend of paying loads of money to go get IV vitamins pumped into you. Unless you have a medical condition that causes malabsorption, as long as you have a well-rounded diet you do not need to buy expensive additional nutritional supplements. Whole foods are better than supplements, because you are getting the benefit of multiple nutrients in one.

There are exceptions to this, like Vitamin D in northern climates, as I’ve discussed previously. And of course if a blood test shows that you are deficient in something, your GP will prescribe a replacement for this.

A lot of the research I’ve looked at does examine supplementation, but if there is a benefit to be had from some of what is discussed below, I am more interested in where you can find it in your food!

Fatty Fish

I love fatty fish – especially in sushi! These delicious fish include salmon, tuna, lake trout, mackerel, and herring. Their potential role in skin health is due to the fact that they are a rich source of omega-3 fatty acids. In theory, these fatty acids can help keep your skin plump and well-hydrated, and a deficiency may contribute to skin dryness. Omega-3 fatty acids also have the added benefit of being anti-inflammatory, and it is proposed they could have a role to play in preventing facial redness and acne. There have also been some small studies showing that consumption of omega-3 fatty acids improved inflammatory acne lesions. Other good sources of omega-3 fatty acids include cod liver oil, flaxseeds, and flaxseed oil.

Oily fish are also a good natural source of Vitamin D. If you live somewhere where there isn’t enough sun (like the UK or Ireland), the recommended daily intake of Viramin D is 400 IU/10 mcg a day. But even with diet, many of us need to take Vitamin D supplementation.

In skin, Vitamin D is thought to have a role in down regulating IgE skin reactions (allergic skin reactions), and is itself vital to many functions of the skin and in maintaining the barrier.

These fatty fish are also a great source of Vitamin E, which has an anti-inflammatory affect.

They are also full of zinc. A zinc deficiency can lead to issues with wound healing and general skin inflammation. A small study investigated the use of zinc in the treating atopic dermatitis, also known in eczema. There was some evidence that supported oral zinc supplementation as an adjunctive therapy to help improve severity of eczema and decrease the transepidermal water loss.

In other words, fatty fish is full of great nutrients that have been connected to skin health.

Avocados

 Yes, yes, I know I’m basic for loving my avocado toast, but I can’t help the cliché!

Avocados are another great source of Vitamin E, in addition to fatty fish. A small study looking at Vitamin E supplementation did show that it improved erythema (redness) when combined with Vitamin A.

Avocados also includes Vitamin C. We all know the importance of Vitamin C for our skin, and the vital role it plays in collagen formation. Vitamin C deficiency famously causes scurvy, the symptoms of which includes dry and easily bruised skin.

Avocados also contain a great bioavailable source of lutein, and there is some research that shows this could have a protective effect on the skin from damage due to UV radiation. Lutein is a carotenoid vitamin with anti-inflammatory properties.

Tomatoes

Tomatoes are delicious and an incredibly versatile fruit to cook with. They are an excellent source of lycopene, which is a carotenoid that has some evidence to show it has a protective effect in preventing redness and sensitivity to UV radiation. It is an antioxidant with a photo-protective effect.

Lycopenes can also be found in apricots, papayas, and watermelon.

Sweet potatoes 

Sweet potatoes are delicious, and they are full of beta-carotene. Beta-carotene is a fat-soluble derivative of Vitamin A. Vitamin A will be very familiar to any skincare lovers out there as our beloved retinoids/retinol. Small studies have examined the evidence of consuming beta-carotene supplements in the overall elasticity of the skin and the improvement in fine lines and wrinkles.

Cocoa

Yes, cocoa! Coca is very high in antioxidants, and a small study did show some evidence that cocoa consumption was correlated with my hydrated skin. So if you love the occasional bar of dark chocolate, it won’t be doing any harm to your skin! Dark chocolate also contains flavanols, which has some protective effects from sun on the skin and one randomised control trial showed that flavanol consumption had a positive effect on skin wrinkles and elasticity.

Low Glycaemic-Index Food 

The glycaemic index refers to how foods affect your blood sugar level. The more a food will cause a spike up in your blood sugar, the higher on the glycaemic index it goes. Focusing on low glycaemic foods could be helpful in maintaining a healthy weight and be beneficial for diabetes or cardiovascular disease (it is certainly not the only factor or criteria to look at when it comes to what you eat).  

There has been a lot of research on the role of a low glycaemic diet in acne. There is some evidence that acne is associated with a “Western diet” of carbohydrate-dense foods, and that a reduction in consumption may help improve acne overall. Part of this comes from research in non-Western populations, where acne prevalence and incidence was low until the adoption of carbohydrate-dense foods. The suggested mechanism of action is that consistent and long-term consumption of high glycaemic index foods causes a chronic raise in insulin and insulin resistance increasing the amount of insulin-like growth factor (IGF-1) in the blood. This can increase the proliferation of keratinocytes as well as sebum production, both of which are part of the pathogenesis of acne. This is controversial, however there certainly are overall health benefits to eating mostly low glycaemic-index foods.

So what foods are these? 

Some great low glycaemic-index foods are: green, leafy vegetables and fresh fruit, kidney beans and chickpeas, and whole grains. This also includes chicken breast and my favourite, prawns.

The Bottom Line

Nutrition has always been of vital importance to our overall health, and there has always been a lot of interest in the relationship between diet and skin health. However, the pathways are complicated, and it is difficult to accurately establish a causal relationship between the intake of certain foods and skin physiology. It was interesting and fun to look into the foods that have been the target of research, as well as the nutrients and vitamins that were pinpointed as being possibly beneficial. However, the main takeaways are this:

• Unless you have a diagnosed deficiency, don’t waste your money on expensive supplements that claim to do wonders for your skin.

• Enjoy incorporating some of the foods discussed in this article – if you like them – into your diet. There may be some benefit to your skin, and you get to enjoy your food!

• More research needs to be done, but there is interesting work looking at the role food could play in dealing with certain skin pathologies such as acne, psoriasis and eczema – not as a magical cure for skin issues, but as an adjunct therapy.

 References

Cho S, Lee DH, Won CH, et al. Differential effects of low-dose and high-dose beta-carotene supplementation on the signs of photoaging and type I procollagen gene expression in human skin in vivo. Dermatology. 2010;221:160-171. 

Dreher ML, Davenport AJ. Hass avocado composition and potential health effects. Crit Rev Food Sci Nutr. 2013;53(7):738-50. doi: 10.1080/10408398.2011.556759. PMID: 23638933; PMCID: PMC3664913

Jung JY, Kwon HH, Hong JS, et al. Effect of dietary supplementation with omega-3 fatty acid and gamma-linolenic acid on acne vulgaris: a randomised, double-blind, controlled trial. Acta Derm Venereol. 2014;94:521-526.

Kim JE, Yoo SR, Jeong MG, et al. Hair zinc levels and the efficacy of oral zinc supplementation in children with atopic dermatitis. Acta Derm Venereol. 2014;94:558-562.

Kwon HH, Yoon JY, Hong JS, et al. Clinical and histological effect of a low glycaemic load diet in treatment of acne vulgaris in Korean patients: a randomized, controlled trial. Acta Derm Venereol. 2012;92:241-246.

Liakou AI, Theodorakis MJ, Melnik BC, Pappas A, Zouboulis CC. Nutritional clinical studies in dermatology. J Drugs Dermatol. 2013 Oct;12(10):1104-9. PMID: 24085045

Roberts R. L., Green J., Lewis B. Lutein and zeaxanthin in eye and skin health. Clin. Dermatol. 2009;27:195–201.

Smith RN, Mann NJ, Braue A, et al. A low-glycemic-load diet improves symptoms in acne vulgaris patients: a randomized controlled trial. Am J Clin Nutr. 2007;86:107-115

Stahl W, Heinrich U, Jungmann H, et al. Carotenoids and carotenoids plus vitamin E protect against ultraviolet light–induced erythema in humans. Am J Clin Nutr. 2000;71:795-798. 

Yoon HS, Kim JR, Park GY, Kim JE, Lee DH, Lee KW, Chung JH. Cocoa Flavanol Supplementation Influences Skin Conditions of Photo-Aged Women: A 24-Week Double-Blind, Randomized, Controlled Trial. J Nutr. 2016 Jan;146(1):46-50. doi: 10.3945/jn.115.217711. Epub 2015 Nov 18. PMID: 26581682.