This post has been LONG in the making. Look for more regular Preservatives posts in the future!
The primary focus of Nature’s Pulchritude is to educate. This post is the seventh in a series of in depth posts that will educate you about the various preservatives in hair and skin products, as well as their potential toxicity.
Preservatives are added to cosmetics, personal care products, and food to maintain a products integrity and stability by inhibiting or reducing the growth of microorganisms such as bacteria and fungus (FDA). Most products sold via retail sit for extended periods of time during shipping, in a warehouse, and on store shelfs that allow enough time for a product to spoil or cause microbial growth which render the product unfit for use. This is particularly true for products that contain water, such as many conditioners and moisturizers, and other active ingredients (antioxidants and emulsifiers) that would otherwise lose their effectiveness and stability over time.
Preservatives are chosen in cosmetics based on a variety of factors which include ability to inhibit growth over a broad spectrum and method of derivation (natural vs. synthetic). Preservatives tend to be in concentrations less than 2% of the weight of the formula, however, widespread use of potentially harmful preservatives, such as parabens, has been a great cause of concern for some scientists and consumers. The Food, Drug, and Cosmetic Act does not grant the Food & Drug Administration the authority to regulate the use of preservatives unless it is known to be “poisonous or deleterious” (FDA).
HONEYSUCKLE AND JAPANESE HONEYSUCKLE EXTRACTS
Honeysuckle extract and Japanese Honeysuckle extract are made from two different species of Honeysuckle flowers, Lonicera caprifolium and Lonicera japonica, respectively. It is typically extracted via alcohol or 100% carbon dioxide. Honeysuckle and Japanese Honeysuckle contain a variety of phytochemicals. Japanese Honeysuckle contains Methyl Caffeate (C10H10O4), 3,4-di-O-caffeoylquinic acid, methyl 3,4-di-O-caffeoylquinate, protocatechuic acid (C7H6O4), chrysin (C15H10O4) methyl chlorogenic acid, hyperoside (C21H20O12), chlorogenic acid (C16H18O9), caffeic acid (C9H8O4), and luteolin (C15H10O6) (Rahman and Kang 2009). Many of these phytochemicals have anti-inflammatory and antioxidant benefits. Honeysuckle and Japanese Honeysuckle both contain parahydroxybenzoic acid (4-Hydrobenzoic Acid), which goes through a process of esterification to produce synthetic parabens.
Honeysuckle and Japanese Honeysuckle are used as preservatives due to their antiviral and antibacterial phytochemicals. Honeysuckle extract can be found independent of Japanese Honeysuckle extract, and is recommended to be used in concentrations of 5-10% of the formula. Honeysuckle and Japanese Honeysuckle are often sold as a blend, ratio uncertain, for use as a preservative, and is suggested to be used in concentrations of 0.5-2% of the formula. Given the difference in recommended use, it is likely Japanese Honeysuckle (Lonicera japonica) has the higher antimicrobial content. Japanese Honeysuckle and Honeysuckle extracts have demonstrated the ability to deter microbial growth in acidic, low water environments for gram-positive and gram-negative Bacteria, though they are not as effective against mold (Papageorgiou et al. 2009). Another study done in 2009 yielded similar results, showcasing the strong antimicrobial activity of Japanese Honeysuckle (Rahman and Kang 2009).
The primary concern surrounding Honeysuckle extract and Japanese honeysuckle extract is that the extracts contain or are ‘parabens.’ This is a misnomer. Neither extract is known to contain parabens. It is important to make the clear distinction between parahyrdoxybenzoic acid and parabens, as parabens are a synthetic chemical designed to mimic parahydroxybenzoic acid (esters). Parahydroxybenzoic acid is a phytochemical present in a variety of fruits and vegetables including blueberries, cucumbers, and olives. It is assumed that parahydroxybenzoic acid accumulates in cancerous tissues similar to parabens, however, there is no literature that supports or disproves this. The exact composition of Honeysuckle extract and Japanese Honeysuckle extract depends on the manufacture, therefore contamination with other preservatives or chemicals is a possibility. A 2012 study found Japanese Honeysuckle extract to be contaminated for formaldehyde, which resulted in the aggravation of existing allergic contact dermatitis caused by formaldehyde releasers and fragrances (Gallo et al. 2012). It is believed the Japanese Honeysuckle extract leached the formaldehyde releasers from epoxy or phenolic-based plastic packaging (Gallo et al. 2012).
There is presently to published literature that states that the parahydroxybenzoic acid content of Honeysuckle extract and Japanese Honeysuckle extract behaves similar to parabens (accumulating in the body, being an endocrine disruptor, mimic oestrogen), however, this is a possibility. More research should be done on these extracts and their parahydroxybenzoic acid content to further establish their safety. Honeysuckle extract and Japanese Honeysuckle extract both contain a vast variety of phytochemicals that are known to have anti-inflamitory, antimicrobial, antiviral, and anti-cancer properties among other benefits. If you have concerns about Honeysuckle extract or Japanese Honeysuckle extract it is best to err on the side of caution.