Cancer
Food packaging chemical bisphenol A linked to breast cancer
By David Liu Ph.D.
May 30, 2005 - 4:38:00 PM

Bisphenol A (BPA), a food container chemical, affects female fetuses in the womb and increases the risk of breast cancer in the affected females when they grow into their adulthood, according to a study that appears in a recent issue of the journal Endocrinology.

Bisphenol A has been widely used in food packaging materials or food containers, dental sealants, baby bottles and the resins that line food cans for quite some years without anyone ever questioning its safety. Bisphenol A is used to make hard plastics.

Previous studies indicated that small quantities of bisphenol A can leak out of the food packaging material or plastics and can be absorbed by the body.

In the current study, researchers at Tufts University in Boston, Massachusetts, gave small doses of bisphenol A to the mice in the second half term of pregnancy and for four days after giving birth. The dose used was equivalent to the amount of bisphenol A humans were exposed to, according to the study.

30 days after the mice were born, or when the female mice reached their puberty, researchers examined the mice and found that exposure to bisphenol A increased the number and density of terminal end buds where breast cancers are mostly likely to develop. This increase made the milk-producing glands more sensitive to the estrogen hormone and increased the risk of hormone-dependent breast cancer.

It was also found that the higher the dose of bisphenol A a mouse received, the more sensitive the mammary glands were to estrogen. This effect was evident that the growth and structure of terminal end buds were affected by estrogen.

Breast cancer is one of the largest threats to women's lives. One in seven or eight women in the U.S. develop breast cancer in their lifetime.

No singular risk factor has been identified as the main cause for breast cancer although it is generally recognized that factors such as genetics, ionizing radiation, the age of giving birth, and exposure to environmental pollutants attribute to the development of breast cancer.

Bisphenol A is only one of chemicals used in many household products that may potentially cause health problems. Another chemical we reported recently is called phthalate, which has been linked with abnormal development of reproductive organs in pre-birth males.

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