Hazelnuts grow wild in many countries. In Northern Europe the wild variety is called a cobnut. This cultivated variety, the filbert, generally grows in hotter climates.

Hazelnuts are high in monounsaturated fatty acids and are one of the best natural sources of boron, shown to be invaluable in the prevention of osteoporosis. Just one gram of the nut is sufficient to provide enough boron for most people daily requirements.