Ask a Dietitian: What Are the Best Foods for Healthy Skin?
We hear it time and time again: we are what we eat. It's true, the foods that we eat has a significant effect on everything, even the quality of our sleep. But what about our physical appearance? How does the food we eat affect our skin?
Science shows that certain components of the foods we eat actually benefit the health of our skin, giving us that healthy glow we all want. Read on to find out which foods are good for our skin and learn about the role antioxidants, essential fatty acids, hydration, zinc and glycemic load can all have on our skin health.
Antioxidants play an important role in breaking down free radicals (which are harmful oxygen molecules) and reducing UVB sun damage. Antioxidants may also contribute to increased expression of genes associated with DNA replication and repair. To make sure you're getting enough antioxidants in your diet, look for foods with these ingredients:
Vitamin C: This vitamin is not naturally synthesised in the body, so we need to be getting it from our diet. Foods rich in vitamin C rich include citrus fruits, strawberries, broccoli, leafy greens, kiwi fruit and capsicum. Not only does this vitamin aid in collagen synthesis, it will also increase iron absorption and bioavailability of selenium—which is another important nutrient that helps to maintain healthy skin.
Vitamin E/tocopherol: Vitamin E works in partnership with Vitamin C, and its mechanism of action is in working against collagen cross linking and cell damage (aka lipid peroxidation), which are both correlated with signs of ageing in the skin. You can find Vitamin E in vegetable oils such as wheat germ, sunflower, safflower, corn and soy, along with some nuts and seeds such as almonds, peanuts, hazelnuts and sunflower.
Carotenoids: This group includes B-carotene, astaxanthin, lycopene and retinol. These antioxidants all hold photo protective properties, which help protect skin from sun damage. Some of the best sources of carotenoids are carrots, pumpkin, sweet potatoes, mangoes and papaya.
Polyphenols: Like all antioxidants, polyphenols may play a role in reducing oxidative stress (aka cell and tissue damage). We mostly find these compounds in fruits and plant beverages, such as fruit juices, tea, coffee and red wine. They can also be found in vegetables, cereals, chocolate and legumes.
Essential fatty acids
A diet rich in essential fatty acids (EFAs) can be beneficial to our skin health. We call these fatty acids "essential" because they can't be produced by the human body, so we must consume them in our diet. There are two different types of EFAs: omega-3, derived from alpha-linolenic acid; and omega-6, derived from linoleic acid. Both of these can be found in many healthy fat sources such as oily fish, shell fish, flaxseeds, hemp seeds, hemp oil, chia seeds, pumpkin seeds, sunflower seeds, walnuts, sesame seeds, avocados and salmon.
EFAs are essential for the creation of cell walls. They're also involved in regulation of cholesterol levels and are a foundation of prostaglandins. A high intake of the omega-3 fatty acids can help prevent skin dryness and thinning of the skin. The omega-6 EFAs are important in the structural integrity (damage level/ability to heal) and barrier function of the skin. In other words, EFAs help keep your skin hydrated.
Considering up to 60 per cent of the adult human body is water, it is not surprising that hydration plays a role in skin health. Water in the skin can serve a barrier or envelope function and a deficiency of water can be associated with skin issues such as dryness. We lose a large amount of water every day through normal cell processes, along with urination and sweating, so we must be replacing this. Two litres of water per day should be an absolute minimum, with many people requiring more than this (especially if they are physically active!).
Zinc is a mineral which helps maintain the heal and rejuvenate our skin by reducing the formation of damaging free radicals and protects skin's fats and fibroblasts (the cells that make collagen, your skin's support structure). It is particularly useful when skin is exposed to UV light or pollution. Zinc is found particularly in meat, oysters, wholegrains and legumes.
While people often like to try and blame specific foods for skin issues (hello, dairy and acne) it is more likely the components of a food that cause such issues, such as a food's glycaemic load.
A food's glycaemic load takes in to account not just the amount of carbohydrate consumed but also the rate of which it is absorbed. Foods with a high glycaemic index (GI) such as sugar, white bread, white rice are rapidly absorbed which result in elevated insulin levels. Insulin and IGF-1 (insulin like growth factor) have been shown to effect sebum production, increase adrenal androgen synthesis and increase the availability of androgens- which can all contribute to the development of acne. Often dairy products, particularly of the skim variety, can increase IGF-1- giving dairy a bad name. Such increases in insulin and IGF-1, aren't an issue for everyone, however. A first point of call for addressing acne and diet should be minimising high GI foods.
Sugar has been mentioned above for its glycaemic load, but sugar affects the skin in other ways, too. It can promote cross-linking of collagen fibres, which happens as a product of glycation and can speed up the signs of ageing. This occurs through glucose and fructose (both sugars) linking the collagen and elastin in the skin. When this happens over and over again, the skin becomes increasingly stiff and elasticity is reduced. Hyper glycaemia (high levels of glucose) can speed this process up. The research seems to show that once these cross-links ("Advanced Glycation End" products or AGEs) are formed, they are unable to be broken. This glycation is a natural process but the rate at which it occurs may be somewhat dictated by our diet. Where we know sugar has a negative effect, other foods may play a role in inhibiting the formation of these AGEs. These include herbs and spices, such as oregano, cinnamon, cloves, ginger and garlic.
You may notice some commonalities between all the components that benefit the skin. They all tend to be wholefoods found in a balanced diet. By eating a large variety of plant foods for a good dose of antioxidants, along with consuming healthy fats on a daily basis for your essential fatty acids and drinking plenty of water, you will be serving your skin well.
Explore more content like this in our series, Ask a Dietitian.
Health & Performance Collective is the brainchild of Sydney Dietitians Jessica Spendlove and Chloe McLeod. They use their 20 years of combined knowledge and skills as dietitians to work with motivated people to live and perform at their best.