Kumquats - Eat them, but rub them first!
Studies show that limonene - an important essential oil present in these mini citrus bursts - has anticancer properties. Eat about five of the little guys to get a good dose of Vitamin C, carotenes, and lutein. To reap the maximum benefits of the fruits, rub them to release their oils, and eat them whole (peel and all).
Readers Digest August, 2013