<<....women in less developed countries had very low incidences of breast cancer? Surely this is because they have more pregnancies and more breastfeeding.>> That could be one of the hypotheses to test (the pregnancies part, anyway). Other suggestions, more or less crazy :-) could include that these women don't eat the processed and GM food that western women eat, that they use their bodies more, most likely that they die from other causes before they get to the breast cancer stage. Who knows, perhaps sitting watching TV or walking through shopping malls causes breast cancer. Causality has to be carefully tested (remember the recent "research finding" that ran something like *people who had lots of ear infections as children were more likely to end up with diabetes*). There have been six recent articles on statistics on the BBC. http://news.bbc.co.uk/2/hi/uk_news/magazine/7605118.stm See particularly Lesson 5: Causality http://news.bbc.co.uk/1/hi/magazine/7592579.stm I don't mean to be flippant - I DO believe that not-breastfeeding is associated with higher incidences of cancers. I have a hard time, though, believing that more-than-a-few pregnancies can improve a woman's health. Would be interested to hear of research otherwise. Best wishes Jacquie Nutt IBCLC *********************************************** Archives: http://community.lsoft.com/archives/LACTNET.html To reach list owners: [log in to unmask] Mail all list management commands to: [log in to unmask] COMMANDS: 1. To temporarily stop your subscription write in the body of an email: set lactnet nomail 2. To start it again: set lactnet mail 3. To unsubscribe: unsubscribe lactnet 4. To get a comprehensive list of rules and directions: get lactnet welcome