These things are heard from the neighbors or from the elders and have no scientific basis. Any type of food taken in sufficient quantity is enough for the required milk production. The more the baby sucks the breasts, more is the flow of milk. The size of breasts depends upon the layer of fat beneath the skin.
Milk production depends upon special glands in the breasts, which are sufficient in all women.
Certain people may have some problems with some food products but others may not. If a certain thing causes some problems to your child, you can try eating it in small quantities. If it causes a problem always then you can stop eating it. It can only be proved wrong by experimenting on yourself. The belief that the baby can catch cold if mother works in cold water, is not true.