Spearmint oil houses a plethora of vitamins, minerals and antioxidants. Its uplifting aroma is on a par with that of peppermint, and both essential oils are very popular. Scientific research indicates that spearmint boasts good total flavonoid (plant pigments) and phenolic (aromatic) content, while providing high level antioxidant activity. Moreover, spearmint may help to lessen any swelling.