13 “Healthy” Spices That Secretly Sabotage Your Anti-Inflammation Diet

9. Fennel: Hormones in the Mix

Fennel has long been a friend to digestion and a staple in Mediterranean cuisine, thanks to its subtle licorice flavor. However, the plant is also rich in phytoestrogens—plant compounds that mimic estrogen in the body. While this can be helpful for some, it may prove problematic for certain groups, especially those dealing with hormone-sensitive health conditions like breast cancer or endometriosis. Others, including pregnant people or those on hormone therapies, are also wise to be cautious with fennel supplements or teas consumed in excess. Most can enjoy modest amounts sprinkled on salads or baked into breads without trouble, but always check with your health provider if you’re in a group requiring hormone balance or are considering more than just a few seeds here and there.

10. Oregano (Especially the Oil): Potency Problems

Oregano turns up the flavor in Italian sauces and Mediterranean dishes and is often touted for antimicrobial qualities. Yet, the more concentrated the form, the greater the risk of side effects like digestive upset, mouth irritation, or allergic responses. Oregano oil—sold as a supplement or remedy—can overwhelm sensitive systems and is not regulated for safety or dosage. A sprinkle of dried oregano in your food is generally safe for most, but self-dosing with drops or capsules of highly concentrated oil can lead to a range of symptoms, from upset stomachs to allergy flares. If you’re intrigued by oregano’s reported benefits, try the leaves in your cooking first, and only use more potent forms with professional support.