Papain itself is found almost exclusively in papaya (Carica papaya), and this enzyme is what poses risks in pregnancy, especially from unripe papaya and its latex. While several other plants contain similar proteolytic enzymes (such as ficin, bromelain, and actinidin), they do not contain papain itself, they have their own distinct enzymes that may or may not have similar risks.
Other Plant Enzymes Similar to Papain
- Fig tree (Ficus carica): Contains ficin, an enzyme similar to papain, found in fig latex.
- Pineapple (Ananas comosus): Contains bromelain (in the stem and fruit).
- Kiwifruit (Actinidia deliciosa): Contains actinidin, another proteolytic enzyme.
Risks in Pregnancy
- There is clear evidence that papain in papaya can stimulate uterine contractions and endanger pregnancy.
- For ficin (from fig) and bromelain (from pineapple), there is far less clinical evidence of causing miscarriage or preterm labor when consumed in dietary amounts, but very high/medicinal doses of these enzymes should be approached cautiously in pregnancy.
- Among common foods, no other fruit or plant besides papaya is known to contain papain itself at levels relevant for human exposure or risk.
Summary:
Only papaya contains true papain in amounts significant enough to pose a direct risk in pregnancy (especially unripe papaya or its latex). While plants like fig and pineapple contain similar enzymes, they do not contain papain itself and, in normal food amounts, are generally not considered hazardous for pregnancy in the same way as papaya
