31 August 2009

Parabens - Hype or a concern?

Parabens are used in cosmetics because they exhibit broad spectrum anti-fungal and antibacterial activity, that is, they kill fungi and bacteria that may contaminate and spoil cosmetics. You are most likely to encounter them in moisturisers, skin care lotions and creams, shampoo, sunscreen, gels and shaving creams. Parabens occur in nature (more about that later), but are mostly synthetically produced by the esterification of para-hydroxy benzoic acid (pHBA); hence, the name: paraben. pHBA is an organic acid found in most plants and used in many metabolic pathways by plants. Parabens are easy and cheap to synthesize, and therefore attractive to the cost-conscious cosmetic's industry. The most common are:
  • methylparaben
  • ethylparaben
  • propylparaben
  • butylparaben
  • isobutylparaben
Parabens have not been shown to cause cancer and the American Cancer Society disavows the rumours out there that say otherwise. So then, what is the concern? In 1999 researchers discovered that parabens and their precursor, pHBA exhibited estogenicity, that is, they mimic estrogen activity. Since upwards of 80% of all breast cancers rely on estrogen to fuel their growth, this is of concern. In 2004, Phillipa Darbre et al discovered parabens in breast cancer tumours. This was not a causal link, but warranted further study. Indeed, the EU limits parabens in cosmetics to 0.4% per paraben type and a maximum of 0.8% for a combination of parabens. There are no similar limits in North America. Search 'paraben' in the EWG's Skin Deep Cosmetic Database and you will find a wide array of concerns. Darbe followed up in 2005 specifically looking at the estrogenic activity of the paraben metabolite p-hydroxybenzoic acid (pHBA). She capped it off with the 2008 study, Paraben esters: review of recent studies of endocrine toxicity, absorption, esterase and human exposure, and discussion of potential human health risks and not only confirmed the intact transmission of parabens across the skin barrier into the blood and urine, but concluded that we simply don't know enough to declare parabens safe and as such the precautionary principle might be useful until we know more.

So, where does this leave us? Well, at the very least if you want to avoid parabens, you are going to have to read labels and ask questions. Companies may claim that parabens occur in nature. pHBA certainly does, but it's estrogenicity is thousands of times less than paraben esters. Methylparaben can be found in strawberries and blueberries - but in minute concentrations, far less than you will find in typical synthetic paraben ester laden lotions, potions, sprays and shampoos. If you are concerned about estrogenicity, you might want to avoid parabens, synthetic and natural alike, though synthetic paraben esters will be many times the concentration than those paraben precursors that are found in nature.

What we can look for is further research on the subject, with particular interest in whether there is a causal relationship between certain cancers and paraben (and/or other environmental estrogen mimics) exposure. Until then, there are many proven alternatives out there, so if you want to avoid synthetic parabens, it's not only possible, but relatively easy with a little homework and label reading.


Anonymous said...

I agree. There's really no reason to use products with parabens...because there are so many better alternatives.

master said...

Parabens are not in the top 3,000 causes of death in this country but some people behave as if parabens are worse than heart disease and obesity.