That's ridiculous! Sorry to hear that your buddy is such an ignorant asshole!
Yes, we can debate the true health impacts that implicate whether breastfeeding is or is not warranted in an African location all day. But the reality is we need to worry about the mothers and babies here in the US first.
Now, as far as developed coutries and your sister….
She should be extremely proud to have fed twins for 4 months, that's not easy! Furthermore, yes, we obviously have a breastfeeding issue as a whole, within our country! But, what I want to say stands out the most about what you said is that it negatively impacted her health as a mother, to breastfeed. It should be made known that those negative health impacts are directly related to poor oversight and care by her doctor and health care team! A mothers health should never be compromised just to provide food for their child. If her physicians were properly caring for her health and monitoring her, as they should have been, she shouldn't have had any issues! I'm sorry to hear that she was let down in such a way!
And to further prove my own point about breastfeeding issues in our own country, the whole boob war can be a perfect example! People should not take offense to seeing female breasts. They were created to feed and nurture our children. Obviously they have become extremely sexualized, but we have to get rid of the stigma somehow and normalize seeing boobs somewhat within our culture.
Depends on the drugs! Those most commonly used during labor and delivery do NOT contraindicate breastfeeding!