We all know that walnut is said to be ‘brain food’, and this isn’t a total myth. Modern research has shown that walnut increases serotonin levels in the brain, thereby assisting learning and memory function (at least for rats using maze tests).
But walnut’s Latin names tell us about another quality: Juglans regia means ‘nuts of Jupiter’ and ‘royal’. To Romans two thousand years ago eating walnuts conferred sexual vigour, and who was more vigorous than the god Jupiter?
We now know that walnuts contain plentiful arginine and zinc, both of which support the human sexual response. More generally, eating walnuts regularly has long been regarded as good practice for maintaining health, especially in older age. In current terms walnut is a superfood that can reduce cholesterol levels and have positive effects on heart health.
Note that because walnut contains high levels of omega-3 fatty acids it remains prone to rancidity. So don’t keep fresh walnuts for more than a few months. Walnut oil also does not keep well.
You can use the green nuts, while the shells are still soft and the nut unripe, for pickling or for tinctures; the liqueur nicino is made from green walnuts. The astringency of the green shell and early leaves can be utilised as a mouth gargle or for throat ulcers, and the green tea helps soothe coughs, asthma and stomach ulcers.