The Essential Fatty Acids

Small amounts of certain "unsaturated" fatty acids may be essential for full health of man, though there is no conclusive evidence on this score. Linoleic acid is the most talked about of these fatty acids. It is so abundant in almost all vegetable oils that it is difficult to devise a diet that could approach a critical level, if there is one. Certainly the general diet recommended here, using vegetable oils in preference to the saturated fats, is far more liberally supplied with the essential fatty acids than are more customary British diets.

The B Vitamins and Ascorbic Acid The water-soluble vitamins include the members of the B complex and ascorbic acid, or vitamin C. Such concern as we have in this country about vitamin deficiency is most legitimately directed towards this group. Being water-soluble, they are readily leached out of foods by prolonged cooking in a super-abundance of water, and this is lost if you then discard the liquor.

Besides this inexcusable method of losing the vitamins (and minerals), some of the water-soluble vitamins are destroyed by prolonged cooking, particularly thiamine (vitamin B1) and ascorbic acid (vitamin C) in alkaline media. We have already condemned the addition of baking soda, which is alkaline, in cooking vegetables. Copper and iron pots also hasten the destruction of vitamin C, though we have not been impressed by the seriousness of this in our own experiments which were carried to indecent lengths for good cookery. We even tried adding copper to the cooking vegetables without destroying very much vitamin C when we were attempting to devise nearly vitamin-free diets for dietary experiments.

Thiamine (B1) is probably the most critical of the vitamins. A diet devoid of this vitamin produces trouble in man in a few days, the first signs being loss of appetite, nausea, and apathy. Fortunately a varied diet of natural foods with a good supply of vegetables and some lean meat or whole-grain cereal takes care of ordinary needs. Organ meats (heart, liver, kidney) are excellent sources, and among muscle meats pork is better than beef. All of the legumes (beans, peas, lentils) are rich sources, as are the whole grains. The discussion about white and brown bread and the National Loaf has been principally concerned with the appropriate level of vitamin B1 in flour of different degrees of "extraction".

Niacin (the anti-pellagra vitamin) is widely distributed in foods - in meats, fish, nuts, poultry, and most fruits and vegetables. Monotonous diets in which corn meal is the major item can lead to the triad, "dermatitis, diarrhoea, and dementia," that is, to pellagra, because of niacin deficiency. This old plague of the Southern United States disappeared as soon as a greater variety of food was ushered in with the improved economic situation.

Nicotinic acid and its amide, nicotinamide, are equivalent in vitamin effect; either may be used to combat pellagra. But nicotinic acid and not nicotinamide, has a special effect in heroic doses many times that needed for the vitamin effect, on the blood cholesterol level. This is discussed in Chapter 1 under DRUGS.

Other vitamins in the B complex are important too, but their abundance in all varied diets of natural foods, especially in such a diet as recommended in this book, robs them of practical interest for ordinary people. Perhaps riboflavin, sometimes called vitamin G, and sometimes vitamin B2, is an exception deserving a comment, because it was once the subject of "scare" articles in the popular press. First estimates of the amount of riboflavin needed to assure coverage of all ordinary human needs were unduly high, and tentative recommendations for a good dietary allowance were still higher. Dietary surveys indicated that many people were not getting as much riboflavin as provided in these super-generous recommendations, but the excitement about this riboflavin "deficiency" in millions of people was deflated by more accurate studies of the "requirements". Riboflavin is abundant in whole grains, meats, poultry, eggs (both white and yolks), and practically all vegetable leaves and stems. Skim milk, liver, and kidney are very rich sources of riboflavin. Beer is also a significant contributor !

Vitamin C (Ascorbic Acid) There has been some difference of opinion between British and American nutritionists about the desirable level of vitamin C in the diet and the American figure has been set two or three times higher than the British. The main sources of this vitamin are potatoes and green vegetables; what northern Europeans did for their ascorbic acid before the potato was introduced from America in the sixteenth century is a mystery. The tomato (another food unknown before the discovery of America) is also a very fine source of vitamin C, but only in quite recent times have we been eating many tomatoes. The development of a year-round supply of oranges and grapefruit and especially the adoption of them and their juices as the standard way to start the day at breakfast, added to the much increased popularity of tomatoes, has meant a vast increase in our consumption of vitamin C.

This is all to the good and we heartily subscribe to the modern trend. Our menus are strong on the side of ascorbic acid. We advocate oranges as between-meal snacks and for dessert, as well as the use of citrus fruit at breakfast. Grapefruit, too, serves to begin and end meals. We also suggest fresh tomatoes for midmorning or mid-afternoon refreshment. The small yellow Peruvian or "plum" tomatoes are excellent for this purpose, and they happen to be extraordinarily high in ascorbic acid. Green peppers, too, are another very rich source of vitamin C.

But frankly, our emphasis on citrus fruits and tomatoes is not only because of their ascorbic acid content. We insist that these are extremely good foods, a perennial delight to the cook and the consumer, be he a plain eater or a fastidious gourmet.

You would think the citrus producers would be content to see the demand for their wares so much increased, but particularly in the United States they tend to gild the lily. Florida growers make unjustified claims about warding off or treating colds with citrus products. Most mysterious is the absence of published or legal challenge to the extravagances in these advertisements.