New research is beginning to be undertaken in order to examine how fermented food can enhance overall skin appearance and alleviate skin conditions. Much of the research is preliminary, but it shows scope for the possibility of new uses of fermented products.
A key angle of research looks at overall skin health, and there are several studies examining the link between ingesting fermented products and healthier-looking skin. Whilst ‘healthy’ skin is a subjective measure, some studies focus on the links between fermented food and hyaluronic acid production. Hyaluronic acid is used for many functions throughout the body, but in the skin it can help retain moisture and alleviate the symptoms of dry skin. Hydrated skin also reduces the appearance of wrinkles and can help keep the skin smooth and firm. Hyaluronic acid is present in many beauty products, often as a form of topical liquid. However studies suggest that eating certain fermented foods boosts the body’s own production, leading to better looking skin.
Different studies have examined different types of fermented products and their beneficial effects. In one study, natto-fermented Radix astragali (Astragalus root) was shown to increase hyaluronic acid production in skin cells compared to a non-fermented control. Another study found the same effect of increased hyaluronic acid production from giving participants a fermented barley and soybean mix. In yet another study, researchers found that participants who consumed a fermented milk drink ended the study with higher skin hydration levels than a control group, with the researchers hypothesising in this case that the probiotic bacteria created an environment which reduced the presence of phenol-producing bacteria. (Phenols are substances known to affect the differentiation of keratinocytes, cells in the outer layer of the skin; maintaining a healthy outer skin layer is thought to help skin hydration levels.) Many of the trials cited are small, limited in scope and fail to establish a causal link between the ingestion of fermented foods and improved skin health or moisture levels. However, they do indicate that eating fermented foods could have beneficial effects for skin appearance, in addition to the other known health benefits of fermented products.
Fermented foods may also have implications for specific skin conditions. The skin is inhabited by a range of microorganisms which form ‘a complex and dynamic ecosystem, determined by a number of physical and biochemical factors’. Bacteria normally resident on the skin produce small molecules which act to promote the immune arsenal and help the skin act as a barrier against infection. When this ecosystem is disturbed, it can result in skin conditions such as acne and eczema. Disturbance can be as a result of a range of factors, including changes in the immune system or changes in the balance of bacteria on the skin, which can result in inflammation and skin disorders. (Rosacea, for its part, is thought to be connected to a disturbed gut biome.) Researchers have found that consuming certain probiotic strains is tentatively associated with alleviation of eczema and acne symptoms. This finding is especially important, as it may help serve as an alternative to the use of the sometimes less-than-ideal traditional treatments to these conditions.
One study even looked at the topical (i.e. on-skin) application of certain probiotics. The researchers found that this method successfully helped to reduce the presence of many antagonistic bacteria, and also helped stop biofilm formation. Biofilms are a community of bacteria which secrete a sticky layer, allowing them to trap nutrients and resist ‘hostile environmental conditions’. In the case of acne, biofilms are thought to impede acne treatment and act as a source of antibiotic resistance In theory, an alternative topical probiotic application could reduce the need for antibiotic creams, a key innovation in a world where antibiotic resistance is becoming more prevalent. Although the exact mechanisms that lead to the positive effects of topical probiotic application are not known, the researchers recommended this method as a possible treatment for acne. If more research is undertaken, it opens up the possibility that fermented or probiotic products may be used in clinical treatments of particular skin disorders.
Indeed, the potential applications of fermentation have not escaped the beauty industry, with many beauty blogs touting the benefits of applying fermented food (such as yogurt) directly onto the skin. The fermentation process has also spawned a range of ‘fermented beauty’ products: the theory is that, as substances are broken down into smaller components during the fermentation process, fermented products will be able to penetrate more deeply into the skin. While these claims are very much unproven, it is reasonable to conclude that promoting a healthy gut can have a positive effect on skin health, and that eating certain fermented products may help boost the skin’s appearance. And, while a fermented food face cleanse may not be to everyone’s liking, the more adventurous may wish to experiment and see for themselves whether the path to amazing skin lies in a sauerkraut facial.
Article by Seb Fagan
Image: Miss Morice