Anti-inflammatory. Digestive support. Fennel contains the phytochemical limonene, which appears to offer anticancer and anti-inflammatory benefits, at least in animal studies and in vitro. More definitive work indicates that anethole, another phytochemical in fennel, can improve digestion, loosen chest mucus, soothe a sore throat and stomach. Anethole is also thought to have excellent antibacterial and antifungal properties. Fennel is a good source of potassium, essential for regulating fluid balance in the body.