wow. I don't agree with this statement at all. I hope that you've accidentally missed some important information out of that sentence and don't mean to make such a harsh generalisation.
Barb is correct, as most research concludes that breastfeeding lowers the mothers risk of breast and ovarian cancer, as well as protecting babies against asthma, allergies, gastro and ear infections in their babyhood, and diabetes and cancer in their adulthood. The longer the period of breastfeeding, the greater the health benefits.