Recently, the delicious and easy-to-crack nuts from the walnut tree (Juglans regia) have received a lot of attention because of their rich stores of omega-3 fatty acids and other healing nutrients. But for centuries herbalists have recognized the healing properties of another part of the walnut tree--its pointy green leaves.

High concentrations (up to 10%) of astringent compounds called tannins account for most of the healing qualities in walnut leaf preparations. Tannins tighten and constrict tissues, making them valuable for protecting areas of skin and controlling inflammation and itching.

Topical formulations of walnut leaf are popular treatments for mild and superficial eczema and for excessive sweating of the hands and feet. In France in particular, the leaf is often applied to sunburns and to scalp that is peeling and itching from dandruff. The herb is useful for a host of other mild skin disorders as well.

According to researchers, walnut leaves even have bacteria-killing, anti-parasitic, and insect-repelling properties. This largely confirms long-held folk beliefs about the healing qualities of the leaf. An intriguing survey of older farmers and shepherds in central Italy, published in the Journal of Ethnopharmacology in 1999, found that walnut leaf was one of the local plants most frequently used for repelling insects and treating parasitic infections on the skin.

Origins. The walnut tree Juglans regia is also known as the English, Persian, or Carpathian walnut tree; it is just one species in the vast walnut family called Juglandaceae. About one-fifth of all Juglandaceae species are Juglans, including black walnuts (J. nigra), butternuts (J. cineria), and heartnuts (J. ailantifolia); all these are believed to have tannins and other healing compounds in their leaves.

Although the J. regia tree had its origins in eastern Europe, it is now cultivated throughout North America, Europe, North Africa, and other temperate regions of the globe. Most of the walnuts produced for consumption are cultivated in California.

Preparation. Typically, the walnut leaves (not the nuts themselves) are dried and chopped before boiling them to make a very strong tea (decoction). Once cooled, the tea is used in compresses, rinses, and other formulations that can be applied to the skin. It can also be added to bath water.

To make a decoction (boiled tea), use 1.5 ounces of dried, cut-up leaf per 1 cup (8 ounces) of water; bring the mixture to a boil in a small pot and simmer gently for about 15 minutes. Allow to cool before using it in compresses and other topical formulations, or in soaks.

There are no known drug or nutrient interactions associated with walnut leaf.

Walnut leaf has been safely used through the centuries as a home remedy for skin conditions. Given its astringency, however, be sure to apply walnut leaf preparations so that the affected area still gets enough air circulation. For the same reason, avoid covering large parts of the body simultaneously with walnut leaf compresses.