In India, fennel seeds are often served as a post-meal digestif and breath freshener. When you crush them between your teeth, these anise-flavored seeds release a compound called terpenoid anethole that may increase gut motility and inhibit GI spasms, says Cynthia Yoshida, MD, a gastroenterologist and the author of No More Digestive Problems
. The theory is that the seeds act as anti-sposmodics, relieving gas, cramps, bloating and stomach upset (but the scientific research is still inconclusive). Because they contain a fair amount of insoluble fiber, Yoshida says the seeds may also help with constipation.