By Belinda Carli
With an increasing focus on holistic approaches to living, the use of food ingredients for skin care appeals to consumers more than ever. If an ingredient is good enough to eat, it also gives an impression of being pure and nutritive, both of which are appealing for consumers to want to apply to their skin.
However, the use of some food ingredients in personal care products may just be marketing hype; being a food ingredient doesn’t necessarily mean it’s a good choice to apply on the skin. Instead of discussing the many food ingredients already being used in personal care products, this article will look at some myths surrounding the use of food ingredients in personal care products, and the realities of food ingredients used in skin care products.
I’ll also be exploring some of the issues relating to the regulations surrounding cosmetic products making nutrition-related claims, and food products making beauty claims. So… just how edible are even the most carefully formulated cosmetics?
Ingestibles and cosmetic claims
Cosmetics are generally defined as products used to cleanse, condition or maintain the appearance or odour of the skin. This means cosmetic regulations should not be used as a guide to creating products for ingestion. Similarly, foods are considered to be products ingested as a source of nourishment; and are subject to relevant country regulations.
These regulations stipulate the use of certain ingredients as suitable for foods within specified limits, as well as suitable forms. In Australia, for example, it is actually illegal to make beauty-related claims about products that can be ingested, unless they are listed with the Therapeutic Goods Administration as a medicine! In addition to the regulations that exist around the world, it may just be bad science to suggest that an ingested ingredient may have benefits to the skin or is suitable for use on the skin.
For example, skin is composed of protein, collagen and elastin, but certain proteins consumed in isolation could lead to deficiencies of absorption or functionality of other proteins within the digestive system, and could actually cause harm. Proteins and peptides that are ingested as concentrates may not be absorbed when not ingested as a whole food; and in any case, if a person is consuming enough protein from food sources (such as meat, egg or dairy products) then any ‘extra’ proteins/peptides may simply be converted to excess energy and stored as fat, without providing any nutrient benefits.
Collagen and elastin are also proteins. Any collagen and elastin that is ingested (if their form is even permitted by regulatory authorities to be ingested!) is broken down by enzymes in the intestine to their peptide and amino acid units so do not, as commonly believed, get carried straight to the skin as collagen and elastin units.
Again, when consumed in excess of what may already be obtained through the diet through whole ‘normal’ food sources, they will just be converted to fat and stored. Unfortunately, we see a lot of ‘food’ products claiming to support beauty when balanced nutrition may instead be more suitable. Question the science and see if a food source isn’t a better choice. If you are looking for good nutrition support for your skin, then the best advice may be what you’ve been told for years: eat good balanced nutrition from a variety of whole food sources!
Preservatives must suit the cosmetic
While there are certain preservatives that are used in foods, it doesn’t necessarily mean they are suitable for cosmetic products. For example, benzoic acid, sorbic acid and their salts are commonly used in food products and may be in some cosmetic products; however their use in cosmetics is limited because they are only effective up to a pH of around 5.0, while most cosmetic products are pH regulated to 5.5 or above – making the choice of other preservatives necessary for personal care.
In addition, many foods may come prepared anhydrous (without water) or at an extreme pH that would not enable microbial growth, and therefore not need preservation. This is not the case for most cosmetics, which commonly contain high inputs of water and a microbe-friendly pH. These same cosmetics may also be subject to repeated consumer contamination over a two or three year shelf life – so good preservation of a cosmetic, where it may not be needed for a food, is essential
This means the preservatives in many so called ‘edible’ cosmetics may not actually be food grade, but have instead been selected to suit the product. True food grade preservatives commonly found in cosmetics include sorbic acid, benzoic acid and their salts – contrary to popular belief, these materials, when used in personal care products, are synthetically produced in commercial quantities and are not natural.
They are also only suited to preserve acidic environments which may not suit
many cosmetic formulations. Propylparaben and methylparaben – we all know the controversies surrounding parabens, yet you may find these preservatives in your foods and your medications. There are multiple country government sites confirming their suitability within regulated limits for personal care use.
Ethyl lauroyl arginate – limited in effectiveness over a pH range of 3 – 7, it is also incompatible with anionic surfactants, cellulose, xanthan gum and bentonite, limiting its suitability for a lot of cosmetic formulations.
Benzyl alcohol – synthetically produced for use in cosmetic products, its effectiveness is again pH limited to acidic conditions. So generally, even if your cosmetic product is claiming it only uses food grade ingredients, it probably contains a cosmetic grade preservative.
This doesn’t mean it’s unsafe. On the contrary – when used within regulatory limits, preservatives for personal care are considered safe and suitable, including those selected specifically for use on mucosal membranes (inside the mouth, for example, as used in oral hygiene products).
When good isn’t great
There are some great food ingredients that simply don’t make sense to apply to the skin. As the most basic example, water is necessary to drink in large quantities daily, but when applied to the skin it simply sits on the surface. In personal care products it is a very necessary solvent, but provides no hydrating benefits to the skin yet is necessary to hydrate the body when ingested.
Spices can flavour foods; but in personal care products, many can be potential irritants. We have seen lip balms in the past contain chilli to create an inflammatory reaction to make lips appear ‘fuller’, but the subsequent undesirable irritation has not been appreciated by consumers.
Finally, the use of certain (usually citrus) essential oils to flavour foods is not uncommon, but when used in personal care products they may cause irritation, or in the case of lime and lemon, make skin hypersensitive to UV light which can lead to blistering if used in even small proportions in leave-on skin products. In addition, many essential oils used in personal care products could be harmful when ingested – another example of where natural, used in the wrong way, definitely does not equate to safe!
Food and skin intolerances
Even if someone has an intolerance to an ingredient when ingested does not mean it will cause them an issue when applied to the skin. Unfortunately, we are seeing more and more bad science ‘free-from’ claims being applied to personal care products that just don’t make sense. Common examples include:
Gluten free: gluten intolerance and health conditions affected by gluten is an immune mediated intestinal condition of sufferers who ingest wheat and related grain products. The symptoms of gluten intolerance are not affected by topical application of gluten-containing personal care products, as the skin does not try to digest (break down) gluten on application.
Nut allergies: unfortunately, we are seeing some nut oils be avoided in cosmetics unnecessarily. If you consider the actual science of a nut allergy, it again relates to the immune system and is relevant to the allergenic proteins found in some nuts and peanuts when ingested. Those with true nut allergies may have issues with nut oils when ingested, but the skin simply does not have the digestive receptors that cause the allergic reaction that occurs on ingestion. Just don’t get nut oils around your mouth in case of accidental ingestion, and you’ll usually be fine to use nut oils in cosmetic products.
Lactose free: lactose intolerance relates to the inability of the digestive system to break down lactose present in milk (and other dairy products). Milk or dairy products, hydrolysed milk proteins, lactose and lactic acid will not have the same effect when used topically on the skin.
What is done well?
Without a doubt, there are a lot of food ingredients that are high in antioxidants when ingested, and when applied on the skin. There are also a lot of ‘interesting’ product stories to be made out of exotic fruit and plant materials that have a history of ingestion. We’re also seeing some fantastic ‘super foods’ translate to great cosmetic materials, such as acai, chia seed, Kakadu plum, maca quinoa and pomegranates as well as some interesting food sources providing unique skin nutrient profiles including caviar, probiotics and a variety of edible kelps.
What works well is when the material contains biomimetic fatty acid profiles and/or vitamin and mineral profiles that are absorbable, or protein profiles that are protective and nurturing to the skin. Look for specific skin compatibilities on application, rather than intestinal nutrient absorption when determining how well a food ingredient will translate to skin care use.
Surpising food-grade ingredients
Just because an ingredient is synthetic does not mean its inedible. Just because it’s a cosmetic chemical does not mean its inedible, or that you may not already be ingesting it! Let’s take a look at some of the most common ingredients you are probably already ingesting: Propylene glycol on unprocessed citrus fruit – a common humectant in the personal care industry, this is also considered a food grade ingredient. It has unfortunately got a bad rap in the personal care industry but is considered safe for personal care and food use.
Butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) as anti-oxidants in edible oils – they are also commonly used as anti-oxidants in fragrances and don’t need to be declared in finished cosmetic product labels when used in fragrance compounds. Again, their use is considered safe as used, despite the controversy you may read on the internet.
Ethoxylated substances, including polysorbate 20 and PEG 8000 are permitted for use as food additives as well as widely used in the personal care industry. Petroleum jelly, mineral oils, ozokerite and microcrystalline wax are common synthetic ingredients in lip balms and lipsticks commonly applied repeatedly every day. Synthetic colourants including tartrazine (CI 19140), sunset yellow (CI 15985), carmosine (CI 14720), allura red (CI 16035) and brilliant blue (CI 42090) are all colourants permitted for use in both food and cosmetic products.
The bitter truth about products good enough to eat While I’ve exposed a lot of the myths surrounding the use of cosmetics as foods, foods for cosmetic purposes, and the irrelevance of a lot of the scare tactics used to get consumers to purposely purchase (or avoid) certain products, there is a lot of good science that supports the use of multiple food ingredients in personal care.
When you’re searching the internet or marketing for that information, just make sure you check the science for sensibility, and question the proposed issues with any ingredients that are considered ‘safe’ when used within limits set by regulatory authorities.
There is nothing wrong with promoting the benefits of an ingredient when it truly has the positive effects it claims to when used in the appropriate way, but there is everything wrong with misleading a consumer as to the suitability (or not) of an ingredient because it is used (or not) in foods.
Remember: even water when inhaled is fatal, yet it’s necessary to be ingested in large quantities daily for good health, but serves only as a solvent in personal care.
Belinda Carli is the director of the Institute of Personal Care Science (IPCS) and the Official Technical Advisor to the in-cosmetics Group, ensuring innovation and high technical content at all in-cosmetics exhibitions. IPCS provides distance training from short course through to Certificate and Diploma levels in Cosmetic Formulation, Brand Management and Regulatory Affairs. Contact firstname.lastname@example.org or visit www.personalcarescience.com.au for more information.