Parabens
From Free net encyclopedia
Parabens are a group of chemicals widely used as preservatives in the cosmetic and pharmaceutical industries. They can be found in shampoos, commercial moisturizers, shaving gels, cleansing gels, personal lubricants, and topical pharmaceuticals. They are also used as food additives.
Parabens are esters of para-hydroxybenzoic acid. Common parabens include methylparaben, ethylparaben (E214), propylparaben (E126) and butylparaben. The general chemical structure of a paraben is shown at right, where R symbolizes an organic group such as methyl, ethyl, propyl or butyl.
Parabens have been linked to breast cancer, but so far there is no scientific evidence to support this claim. Parabens have been claimed to have been found in 20 samples of breast tumors [1], but it is unknown if this would be the same for healthy breast tissue. It is by no means certain that the parabens were present in the tumour tissue as similar concentrations were detected in the blank control samples. Further research is necessary to establish the presence of parabens in breast tumors and to establish a causal link between parabens in cosmetics and breast cancer.
Tests on animals involving injection of parabens have shown weak oestrogenic activity, acting as xenoestrogens [2]. Oestrogen is known to drive the growth of tumors. However, there is no evidence that underarm cosmetics containing parabens pose a health risk, because of the low doses involved and the fact that parabens are unlikely to penetrate into the tissue and to accumulate there (enzymes in skin and subcutaneous fat cells are capable of breaking down parabens). Parabens can cause skin irritation and contact dermatitis in individuals with paraben allergies. Additionally, less than 1% of all underarm products actually contain parabens.
Parabens are extremely effective as preservatives in all types of formulas; for example, parabens can be used to preserve shampoo, lotions and personal lubricants, but a different preservative system would have to be used in each of those products in order to replace the parabens. This, combined with their low cost and the unproven efficacy of natural preservatives like Grapefruit seed extract, probably explains why parabens are so commonplace.