This section is from the book "Practical Dietetics With Special Reference To Diet In Disease", by William Gilman Thompson. Also available from Amazon: Practical Dietetics with Special Reference to Diet in Disease.
The cabbage family, which belongs to the natural order Cruciferce, furnishes many examples of green vegetables, some of which are of value for their leaves, and others for their modified flowers. There are about seventy varieties of cabbages. They contain considerable sulphur, which, if malfermentation exists in the alimentary canal, produces sulphuretted hydrogen, causing flatulence and unpleasant odour. They may also give rise to calcium oxalate in the urine, by causing indigestion, and they should be avoided by the rheumatic or gouty, and, in fact, by all classes of invalids. Cabbages and other vegetables of this order impart a strong taste and odour to the water used for boiling them. When soft and crisp, cabbage is a wholesome food for those with strong digestion, and it has decided antiscorbutic properties when fresh, which are lessened by fermentation.
The principal edible representatives and preparations of the cabbage family are the following:
1. Sauerkraut is made by placing salt between layers of cabbage leaves and subjecting them to pressure, which bruises them and squeezes out their juices. The mass then ferments with the formation of organic acids.
2. Cauliflower and broccoli are the flowers of plants which are grown large and tender by cultivation. When boiled and served with a milk sauce they are much esteemed for their flavour and easy digestibility in healthy stomachs, but they cause flatulence if eaten by dyspeptics. These vegetables may be dressed with olive oil and eaten as a salad.
3. Cole is a plant of the cabbage family which does not "head".
4. Seakale is grown in the dark, so that it has no chlorophyll. It is equally digestible with cauliflower if well bleached. It is more often cultivated in England than in this country.
Spinach, beet tops or "greens," dandelion tops, and turnip tops are all useful green vegetables, and of these spinach, which is slightly acid, is the most common and desirable. These substances afford almost no nutriment, and are valuable chiefly for their laxative action. The mineral salts which they contain, especially those of spinach, have been shown by Luff, of London, to be of positive value in gout in increasing the solubility of sodium biurate and retarding the conversion of quadriurates into biurates. (See Gout.) If the leaves are young and tender, and if they are cooked until they become quite soft and are then chopped into a fine pulp, they are very wholesome articles of food for the relief of chronic constipation. The dandelion leaves have a less delicate flavour than spinach, and are said to possess a slight diuretic action. Unless bleached they are bitter. The dandelion root is laxative, like the leaves, and it forms an ingredient of root-beer.