Pineapples give you vitamins and minerals, potassium, manganese, copper, magnesium, calcium, beta carotene, thiamine, folate, B6 and of course, Vitamin C. That's not to mention its soluble and insoluble fibers beneficial for effective weight loss.
Bromelain is what makes pineapples effectively anti-inflammatory---and inflammation, incidentally, is mostly responsible for a lot of diseases, like arthritis which is fast becoming popular these days. You get rid of harmful inflammation, you get rid or prevent of a lot of deadly diseases. Thus, pineapple is called "the healing tropical fruit."
Of course, another reason for its healing property is its rich Vitamin C content. Fresh pineapples are rich with this vitamin which is essential for enforcing the immune system.
But mind you, it's got to be fresh pineapples. Eat it as soon as you peel it. Hence, the small, cheap pineapples I buy along sidewalks may already have zero Vitamin C and other nutrients. I'm aware of that.
Still, I get its soluble and insoluble fibers and fruit sugar to help me eat less and yet stay energized. That's effective weight loss.
But don't get me wrong---I do love eating fresh pineapples as well, when I have the opportunity. I recommend organic pineapples. Some pineapples are bombarded with chemical fertilizers, so beware.
And oh, pineapple in cans are a definite no-no.
Pineapples also help create collagen due to its Vitamin C content. Collagen is the important protein base of internal organs, bones, skin and blood vessels. Vitamin C also helps your body fight infections, illnesses and helps heal wounds faster.
And I haven't heard of anyone being allergic to pineapples or getting an overdose of it (except irritating your tongue if you eat more than enough). But check with your medical doctor, just to be sure.
If I were you, I'd eat pineapples more often.