New scientific evidence has indicated that common preservative chemicals found in underarm antiperspirants and thousands of other everyday products, can be detected in breast cancer tumours.

These chemical agents, also known as parabens, are found in many toiletries like face wash, shampoos and make-up, as well as, processed meats and pastries and even in the contraceptive Pill. However, this study focused on the possibility that antiperspirants may ‘soak’ through the armpit skin.

Scientists from the University of Reading believe there is an important link between these chemicals and breast cancer after studying the samples of 20 different human breast tumours taken from mastectomies between 2005 and 2008. Researchers measured the concentration of parabens in the tissue of the breast, from armpit to breast bone.

They detected parabens in these samples with a concentration of 20.6 ng per gram of tissue. The chemicals discovered were in their ester form, rather than metabolite form, which suggests that the route of entry was topical, not oral.

Even though few of these women had used deodorants, 99% of the samples contained one or more paraben, while 60% of the tissue samples contained traces of all five of the most commonly used parabens.

Although the link between parabens and breast cancer have been highlighted before in previous studies, with it first coming to light in 1998, the latest discovery is more significant, claims lead author of the study, Dr Philippa Darbre.

"Parabens are used as preservatives in thousands of cosmetic, food and pharmaceutical products but this is the first study to show their accumulation in human tissues," Dr Darbre explains.

"It demonstrates that if people are exposed to these chemicals, then the chemicals will accumulate in their bodies. Their detection in human breast tumours is of concern since parabens have been shown to be able to mimic the action of the female hormone oestrogen and oestrogen can drive the growth of human breast tumours.

"It would therefore seem especially prudent to consider whether parabens should continue to be used in such a wide range of cosmetics applied to the breast area (including antiperspirants/deodorants)."

Many major British and international brands use different types of parabens in products, often listed on the packaging as methylparaben, propyl, butyl or ethylparaben.

However, the authors of the study added that the results should be interpreted with caution and admit that there will be further investigation into these potential links between parabens and breast cancer, as a direct connection is yet to be discovered.

"Dr Darbre and colleagues fully peer reviewed finding of parabens in tumour samples does not imply causality of the tumour and further work is required to examine any association between oestrogenic, and other, chemicals in underarm cosmetics and breast cancer," explains Dr Philip Harvey, European editor of the journal.

The results have been published in the Journal of Applied Toxicology.

Catherine Priestley, Clinical Nurse Specialist at Breast Cancer Care adds: "The debate about the link between parabens and breast cancer is not a new one, and this report serves to highlight the need for further research. There is currently no conclusive evidence to suggest that the use of products containing parabens is directly linked to the development of breast cancer.

"Whilst there are a number of factors that may slightly increase the risk of a person developing breast cancer, increasing age, gender (being female) and a significant family history are the three main risk factors.

"It is important that people should have access to information on this issue and about their risk-factors for breast cancer so that they can make informed lifestyle choices."

The leading factors behind the cause of breast cancer lies within gender (500,000 women are diagnosed each year and only 500 men), age (81% of breast cancer occurs in women over 50) and family history of the disease.

Breast Cancer Care also state these as other leading factors of breast cancer:

• Periods starting before the age of 12.
• Menopause after the age of 50.
• Not having children.
• First pregnancy at the age of 30 or over.
• Taking Hormone Replacement Therapy (HRT) – depending on what type you take and how long you take it (the risk reduces
• over time once you stop).
• Taking the oral contraceptive pill for a number of years (the risk reduces over time once you stop).
• Being overweight, especially after the menopause.
• Drinking more alcohol than the recommended daily amount (two units for women, three for men).
• Exposure to high levels of radiation.