Long Term Breastfeeding May Reduce Risks for Breast Cancer

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Tuesday, November 29, 2005

Mothers have long understood the benefits of extended breastfeeding when it comes to their children's health, but many women are still just starting to learn about the benefits they can reap for themselves by providing breastmilk for their babies for longer periods.

While the jury is still out on whether or not breastfeeding definitively plays a role in preventing breast cancer, there have been several studies that have shown strong links breastfeeding and reduced breast cancer rates. A Chinese study that was conducted showed that women that breastfeed for a very long time (six years total) had a 63% decreased risk of breast cancer over mothers that had never breastfed. A study published in 2001 that was conducted at Yale University also showed that women that breastfed their first child for more than 13 months also had a reduced risk of breast cancer.

A study that looked at data from 47 different studies in 30 countries showed that the incidence of breast cancer is lower among women in developing nations and suggested that this may be because women have more children and breastfeed longer. The study showed that a woman's risk of breast cancer drops by about 4.3% for every year she logs breastfeeding. The risk goes down another 7% for every child born.

Some research has also shown that women who were breastfed as infants have a lower breast cancer risk than women who were formula fed. The theory here is that the hormones and immunities that a mother passes to her child play a role in helping that child's body fight cancer causing agents.

Why would breastfeeding reduce the risk of breast cancer? There are several theories. Some scientists believe that breastfeeding lowers a mother's exposure to oestrogen, a female hormone that promotes growth of cells in the breasts. Breastfeeding lowers oestrogen rates by delaying the onset of ovulation after pregnancy, meaning that the longer a mother nurses her child, the less exposure to oestrogen she has.

Another possibility being studied is that lactating breasts do not store fat-soluble carcinogens and pollutants as well as non-lactating breasts. Thus, extended breastfeeding essential "protects" the breasts from cancer causing agents that might otherwise take up residence in breast tissue. Other evidence suggests that lactating causes a physical change in breast cells that make them resistant to the mutations that can lead to cancer.

Time and more research will help us understand more clearly what the link is between breastfeeding and breast cancer prevention, but for the time being, all major health organizations still support the idea that breastfeeding provides at least some help with reducing the rates of breast cancer. That's why the American Academy of Pediatrics recommends "exclusive breast-feeding for approximately the first six months after birth and that breast-feeding continue for at least 12 months and thereafter for as long as is mutually desired." The World Health Organization goes beyond that, encouraging women to breastfeed until a child is two.

Labels: Stats and Studies

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