Why the core?
The core of the fruit contains the highest concentration of bromelain. The meat of the pineapple does not have the same strength, and pineapple juice is risky as it can act as a blood thinner if you consume too much. Furthermore, pineapple juice, in large doses, can cause uterine contractions, possibly bringing on miscarriage.
Canned pineapple doesn’t work either as the heat used in the canning process destroys the bromelain.
Are there any risks?
Do not eat unripe pineapple. It can be poisonous to your system and will result in diarrhea. How do you tell if a pineapple is ripe? A ripe pineapple is mostly yellow/orange in color with minimal green and the leaves at the top are easily pulled out.
Additionally, be careful not to consume pineapple too early in your cycle as it can affect the pH levels of your cervical mucus, making it too acidic for sperm survival and ultimately conception.