Environmental or Genetic?
Studies have shown that environmental factors play a huge part in the onset of cancer, with only around five per cent being genetically predisposed.3 Environmental factors from this perspective can incorporate anything that people are exposed to, such as substances consumed, smoking, natural and medical forms of radiation, including exposure to the sun, workplace exposures, drugs, social and economic factors and substances existing in the air, water and soil.4 In addition, aging, alcohol, infections, hormonal factors, pollution, lack of exercise, sexual behaviour that elevates exposure to particular viruses and consumer products are all implicated in various types of cancers, to different degrees.
Dr Epstein points out that carcinogens taken in by mouth are absorbed from the intestines and transported to the liver, where they can be detoxified to different degrees, depending on the substance, but carcinogens absorbed through the skin reach can enter the bloodstream without this prior protective detoxification by the liver.
(EU/UK based data) Push to Ban Chemicals Linked to Breast Cancer
The evidence of Oestrogen
In the EU campaigners have urged MEPS to strengthen chemicals legislation, following a report suggesting that some chemicals may be associated with rising incidences of breast cancer. Professor Andreas Kortenkamp, head of the Centre for Toxicology at the University of London, has pointed to significant evidence that the rise in breast cancer is linked to environmental exposures to substances such as hormone disruptive chemicals that mimic oestrogen. In the report commissioned by the health and environmental alliance HEAL and Chem Trust, Professor Kortenkamp said,
“There is overwhelming evidence that oestrogens are strong determinants of breast cancer risks…Given that natural oestrogens and man-made oestrogens used as pharmaceuticals have a role in breast cancer, concerns arise about the potential contribution of industrial chemicals and pesticides with hormonal activity.”11
Oestrogens are required for breast development but they also play a role in the development of breast cancer. Natural oestrogens act on the ‘end buds’ of the epithelial ducts in mammary glands to promote growth through elongation and branching of the duct system. This takes place initially during the foetal stage and then again at puberty and finally during pregnancy. It is this growth of the end buds that links oestrogens to breast cancer. Oestrogens cause an increase in cells that can be prone to cancerous growth. The breast is most susceptible to cancer causing influences during periods of growth, such as during puberty. In the womb, the mother’s oestrogen levels affect the number of end buds that develop in the foetus, with higher levels of oestrogen causing more end buds to grow, this effectively increases the cell pool from which cancer cells can be drawn.
Although Professor Kortenkamp acknowledges that numerous factors play a role in breast cancer, he continues, “There is a case for relinquishing the dominant view of breast cancer as a life-style and genetic disease and for reappraising the role of environmental factors, including chemical exposures. With UK breast cancer incidence at an all time high, risk reduction will not be achievable without considering preventable causes, particularly exposure to chemicals.”12
As well as prohibited industrial chemicals such as PCBs, still being detected in human tissues, there are a host of chemicals used in consumer products that have hormone disrupting properties, including phthalates, bisphenol A, UV filters, commonly used preservatives such as parabens, and numerous others. Many of these have been found to act in a similar way to the sex hormone oestradiol, although much higher concentrations are required to cause as pronounced effects. Environmental pollutants such as PCBS and certain pesticides do not act alone, but in combination with natural oestrogens and other hormonally active chemicals in a woman’s body, including chemicals released during the preparation of food, man-made chemicals including environmental pollutants (dioxins, pesticides, PCBs), synthetic cosmetic constituents (such as some synthetic fragrances, UV filters, antioxidants) and plant derived oestrogens present in some foods. Although the hormonal strength of these chemicals in much lower than natural or pharmaceutical oestrogens, research has shown that quite a significant number of chemicals can enhance the effects of natural oestrogens.13
Professor Kortenkamp presented evidence that whilst low levels of certain individual chemicals have no detectable impact on breast cancer, the combined additive effect of mixtures of these chemicals (even at low concentrations that would not usually present an observable effect), has a much greater impact. Testing a combination of 11 xenoestrogens (man-made chemicals that behave like oestrogen in the human body) on the actions of the hormone oestradiol, Professor Kortenkamp found that the combined effect of the xenoestrogens led to a dramatic enhancement of the hormone’s action, even when each agent was present at levels that do not individually generate measurable effects.14
Other research demonstrated than four organochlorines acted together to enhance the proliferation of human breast cancer cells, suggesting again that mixtures of certain chemicals produce a combined effect even when each agent is present at concentrations that individually produce insignificant effects. The combination effects of the mixture were stronger than the effects of the most potent individual component (thus the combined effects were synergistic).15
Many studies have found that the risk of cancer developing is elevated if exposure to carcinogens begins in infancy, rather than later on in life. Young children have a greater susceptibility to carcinogens because the cells rapidly divide during childhood and if they are rapidly dividing following exposure to a carcinogen, any genetic mutation that has occurred is more likely to be fixed.23 There are various other reasons why babies, young infants and children are at greater risk. For instance, children take in more oxygen per kilogram of body weight than an adult and therefore more air pollutants, low molecular weight compounds can readily cross the placenta, newborn babies have more absorbative skin because it is not fully keratinised (therefore without one of the skin’s main protective barriers) until several days after the baby is born and various organs such as the lungs and brain are still developing. Children have different exposures, pathways of absorption, tissue distribution and responses to environmental exposures, and they also eliminate chemicals in different ways.24 This all needs to be considered when looking at the potential adverse health effects of environmental exposures.
The U.S. National Toxicology Program (NTP), an interagency program that evaluates agents of public health concern, produce a report on carcinogens (ROC), which currently contains 246 listings of known and reasonably anticipated human carcinogens.25 Our households and other external environments play host to a variety of known and potential carcinogens. Some of those listed substances we may commonly encounter that are known or suspected of causing cancer, according to the U.S. National Toxicology Program, include:
- Red and preserved meats
- Salt-preserved foods
- Alcoholic beverages
- UV radiation from the sun
- Sunlamps or tanning beds
- Viruses and bacteria
- Ionising radiation - from sources such as radon
- Radioactive substances - released by atomic bombs or nuclear weapons, and x-rays
- Pesticides - such as ethylene oxide, DDT, amitrole, hexachlorobenzene, lead acetate and lindane
- Medical drugs - such as cyclophosphamide and chlorambucil used to treat cancer
- Oestrogens - long-term users of combined oestrogen and progesterone oral contraceptives may have an increased risk of early-onset breast cancers and liver cancer; tamoxifen may also increase the risk of developing endometrial cancer
- Solvents - such as benzene, chloroform, methylene chloride and trichloroethylene
- Fine particles and dust - such as asbesto fibres, ceramic fibres, wood dust and silica dusts
- Polycyclic aromatic hydrocarbons
- Metals - such as arsenic, beryllium compounds, cadmium metal and cadmium compounds, chromium, lead and nickel
- Diesel exhaust particles
- Toxicants from fungi
- Vinyl chloride
- Butylated Hydroxyanisole (BHA)
- Butylated Hydroxytoluene (BHT)
- Coal tar
- Synthetic musks (used in fragranced consumer products)
- Organic solvents (e.g. toluene, formaldehyde, xylene)
- UV filters in sunscreens (e.g. padimate O, para-aminbenzoic acid (PABA), oxybenzone, avobenzone).
- Cosmetic grade lanolin
- Hair dyes
- Diethanolamine (common ingredients containing diethanolamine (DEA) include: cocamide DEA, cocamide MEA, Lauramide DEA, Myristamide DEA, Oleamide DEA etc)
- Artificial colours
Known and potentially carcinogenic ingredients in cosmetics include among other things:
References and the rest of the article: http://toxicbeauty.co.uk/blog/2009/07/21/toxic-beauty-extracts-cosmetics-and-cancer/