Walnut

The walnut is the fruit of the walnut tree, a tree from the walnut family that grows up to 25 meters high and is mainly found in south-eastern Europe, western and central Asia, northern India and China.

Its fruits, the actual walnuts, belong to the nuts and, like the hazelnut and the pecan nut, to the nuts.

The hard shell covers two irregularly shaped nut halves, which are protected by a small membrane. These contain antioxidants and prevent rancidity. The discoloration of the skin when handling the green nutshells is caused by the phylloquinone juglone. The fat content is up to 75 %, mainly oleic and linoleic acid.

Studies indicate an antiproliferative activity of the proteins and protein hydrolysates contained in walnuts: walnut protein hydrolysates showed an antiproliferative effect on breast cancer, colon cancer cell lines, carcinoma cells of the prostate and also leukemia, as well as melanoma cells.

For use in cosmetics, see Juglans regia seed (INCI), Juglans regia shell powder (INCI)

Sensitizations to walnut are rather rare, see under walnut allergy. Like hazelnut, it used to be considered a potent food allergen to which patients with birch pollen pollinosis (see tree pollen below) in particular become sensitized. As no Bet-v-1-like allergens are found in walnuts, this is not the case.

Walnut oil is used for oil paints, but also for cooking.

Various components of the walnut tree are used in cosmetics, see Walnut tree.

1. Blaschek W (2015) Wichtl-Teedrogens and phytopharmaceuticals. A handbook for practice. Wissenschaftliche Verlagsgesellschaft Munich. S 354-356
2. https://arzneipflanzenlexikon.info/walnuss.php