Asparagus juice is usually taken in the quantity of a sherry-glassful three times a day before meals. Asparagus extract has been used not only to remove water from the body but as a purifier of the blood, to tone up the nervous system and as a gentle laxative. The thickness of the asparagus used has little effect upon the value, only upon the cost. So choose fresh looking stems that have not dried out and gone floppy. The white, woody base of the stem helps prevent it from losing moisture. It can be stored for a few days wrapped with a damp cloth around the base and kept in a cool place.
Asparagus is a luxury vegetable that still grows wild in Mediterranean countries. Old herbals called it sparrowgrass and farmers still call the plant 'grass?. A big helping will contain less than 40 calories and it is a good provider of vitamins C and E and folic acid. The therapeutically active substance found in the asparagus is the alkaloid asparagine which exerts a rapid effect upon the kidneys, stimulating them and colouring the urine a dark yellow within hours of consumption.
The asparagine is much reduced in quantity during cooking, so that the use of quite a small amount of the raw juice produces a good diuretic effect. Not only is the urine coloured, the asparagus also imparts quite a strong smell to it, so do not think anything is amiss should this phenomenon surprise you. The essential oils which give asparagus its distinctive and pleasant flavour are very powerful because they are present in such small amounts that special analytical methods have to be employed to detect them.