Minerals

The minerals in foods are important, of course, but they are not apt to be critical for adults living on the kinds of foods and menus recommended in this book. Calcium for bones and iron for blood will not be lacking, phosphorus is not a problem anyway, and the diet we propose is unusually rich in potassium. As for iodine, our liberal use of fish provides more iodine than in most diets.

Sodium, which we get mainly in ordinary table salt, poses interesting questions which were discussed in Chapter 1. The main problem is too much salt. We need not worry about a deficiency even in hot weather when we lose salt in sweat so long as we eat and salt "to taste". Most heat fatigue and heat cramps result from drinking too little water. Salt tablets are needed only when you stop eating because of the heat and foolishly decide to live on beer and spirits or soft drinks.

Heavy salting of food is usually an attempt at compensation for otherwise flavourless cookery. Ten grammes, or a third of an ounce, of salt (as sodium chloride) daily should suffice for any situation, including hot weather, and less than that would be a good general rule. Taste before you salt.

Recently it has been suggested that lack of magnesium in the diet may raise the cholesterol in the blood and promote atherosclerosis. Conceivably, severe magnesium deficiency might have such an effect, but the danger, if it exists, is very remote with anything like a normal diet. The latest researches fail to confirm the idea that magnesium is important in the metabolism of cholesterol. In any case, the diets in this book are unusually high in magnesium.

Modern food and beverage technology, particularly canning foods, adds tiny amounts of certain metals - tin, copper, zinc, cadmium - to the diet. Do these metals contribute to our plague of heart disease? The theory seems to be far-fetched and there is no real evidence of an effect, good or bad. But it should be noted that, for other reasons, we advocate a maximum of fresh foods, so if our advice is followed you may forget about these metals and their possible effects.