Environmental pollutants may benefit human health

Industrial pollutants such as alkylphenols and PCBs have controversially been linked with hormone-dependent cancers, whilst plant chemicals known as phytoestrogens have been marketed as health supplements. But scientists are now suggesting that the story is not quite so simple.

Dr Chris Kirk and colleagues from the University of Birmingham haves been studying industrial oestrogens such as PCBs, insecticides and alkylphenols and a group of chemicals termed ‘phytoestrogens’, commonly found in foods like soy, onions and salads. A commonly held belief is that man-made oestrogens are ‘bad’ and phytoestrogens are ‘good’. Phytoestrogens are already marketed as “phytoceuticals” for a range of treatments including alleviation of menopausal symptoms and breast enlargement. But according to Dr Kirk, the picture is more complicated.

Dr Kirk’s research, which will be presented at the Society for Experimental Biology conference on Thursday 11 April, has shown that both man-made oestrogens and the plant extracts share the ability to change the way our bodies process naturally-occurring oestrogens. Some can inhibit the enzymes involved in the generation and removal of natural estrogens. This may disrupt oestrogen activity in the body, in some cases leading to the development of tumours in adults or reproductive abnormalities in infants.

The precise effects of these compounds may depend upon the age of an individual at the point of exposure, which can influence their sensitivity to oestrogenic chemicals. But it is quite possible that some environmental oestrogens which are toxic to the developing embryo could serve as therapeutic agents for the prevention and treatment of some adult human cancers. “We are urging more research into the effects of these compounds,’ says Dr Kirk.