STAFF OF LIFE

Grey River Argus, 15 March 1940, Page 10

STAFF OF LIFE

It has been computed that the average human being (adult) requires about 300 international units of vitamin Bl each day, if he is to remain in good physical, and mental health. On the basis of this calculation, it is possible to make some estimate of the importance of bread as a source of vitamin 81. If one pound of bread be taken as the amount which may be eaten daily by an adult on an inexpensive diet, and 300 international units be taken as t the minimum daily requirement of vitamin 81, white bread would supply approximately 100 international units, or one-third of the daily requirement; commercial brown bread would supply 270 international units, or nearly the whole requirement; while wholemeal bread would supply 430 international units—considerably more than the minimum requirement. Wanted: A Real Loaf!

“Enough is as good as a feast,” says the ancient proverb; and the modern nutritional scientist can bear this out. As mentioned in our first column of this series, the Lister Institute, has pointed out that large quantities, of bread, be it ever so wholesome cause difficulties for the digestive organs. New Zealanders are a vitamin Bshort race of people; but the full daily requirement of this vitally essential food accessory can be taken into the system by the consumption of about one-third of a 21b. loaf of real wholemeal bread made from wheat grown on fertile soil. It should be emphasised, at this point, that there is at present no such thing in the entire length and breadth of New Zealand as a real wholemeal loaf made from wheat grown on fertile soil.

Vitamin B2: This vitamin, is concerned with important nutritional processes in the living organism. As long ago as 1927 it was discovered that whole wheat contains five times as much vitamin B2 as breads made with flours of 69 to 55 per cent extraction (see paragraph 3 of our first article of this series). The addition of skim milk in the mixing of bread does not appreciably increase the vitamin B2 content of the bread made from flour of about 97 per cent extraction; but it does produce a fifty per cent increase in the vitamin B2 content of breads made from flours of from 69 to 55 per cent extraction. All these losses of vitamin 82, occasioned during the processes of milling, are very significant from the point of view of nutrition, health, sanity and efficiency. The vitamin B2 content of flours is also reduced by bleaching and keeping.

Vitamin A (Carotene): The carotene content of wheat is of practical importance in the milling industry,—not because of its nutritional significance, but because its presence gives flour an undesired yellow colour which it is the ambition of the producers to avoid. It has even been proposed that wheats should be bred which have a low carotene content; and in 1935 experiments were carried out showing that this proposal comes within the bounds of possibility, for the carotene content is an inheritable characteristic. Further investigations have shown that carotene is fairly uniform m the different parts of the grain; so that white flour, before bleaching, does not contain very much less carotene than does wholemeal flour. However, the millers conquer this “difficulty” br their bleaching processes!

The carotene content of flour is considerably reduced when it is kept at room temperature, i.e., by 25 to 30 per cent in 100 to 130 days. Reduction is only slightly less when the flour is stored in carbon dioxide instead of air. The effects of bleaching with chlorine, nitrogentrichloride, henzoyal-peroxide and ultra-violet light have als obeen investigated. In all such cases there is considerable loss of carotene. This loss becomes greater as the concentration of the bleaching agent is increased; and, except in the case of ultra-violet light, the loss actually continues after the bleaching process is discontinued, — presumably as a result of traces of unchanged bleaching agent remaining in the flour. The results with the three chemical agents mentioned above are very similar, the greatest fall in the carotene content occurring immediately after bleaching and being so great that only about 25 per cent of the original carotene remains; and after keeping, this figure is always further reduced.

Poor Old Staff! . The average adult requires 1.8 to 2.7 mg. of carotene daily, in ordei’ to keep fit. One pound of wholemeal bread contains about 0.6 to 1.2 mg. of carotene; so that a man eating a moderate amount of this kind of bread would be able to obtain a goodly portion of his daily vitamin A requirement in this convenient wa>. It thus appears that in a somewhat poor diet, largely consisting of bread, and lacking in green vegetables and fats, bread becomes an important source fo vitamin A —when it is made from unbleached flour. It is also clear that wholemeal bread would supply rather more of this vitamin than white bread made from unbleached flour. Vitamin Aof course, is imperatively necessary for all-round good health, and particularly for good eyesight.

.Vitamin E: The wheat germ is one of the chief sources of v* lamin E. The removal of this constituent ftom the grain in milling therefore lessens considerably the nutritive value of flour. It had previously been taken for granted that most human diets were adequately supplied with vitamin E. Extensive experimental studies in 1935, 1936 and 1937, however, on treatment of habitual abortion with - vitamin E, suggests an all-round shortage of vitamin Ein ordinary diets. The disrtibution of vitamin E in Nature appears to be very uneven, the chief known sources being the germ of cereals and green leafy vegetables. As cereals are all “refined” before being put on the market and as adequate amounts of green leafy vegetables do not appear in the ordinary diet, it is easy to see that the human race is depriving itself of this essential vitamin. While on the subject of the rejection o fthe despised wheat germ, it must be mentioned that this part of the grain is rich in essential fatty acids, so important for human nutrition. '?

To Sum Up:

If one sums up the evidence, states the Lister Institute it is quite clear that the change-over from wholemeal

to white flour that took place when steel roller mills were introduced some 70 years ago has resulted in the reduction of the nutritive value of the protein; in serious lowering oi the content of calcium, phosphorus and iron; in reduction of vitamins A, Bl and 82, and probably complete removal of vitamin E;—all representing dead loss, nutritionally. In order to change back to wholemeal, it is necessary to alter the tastes of the people and to overcome the vested interests in, the existing milling industry,, also to find a means of using wholemeal flour more quickly and of storing it more satisfactorily. The advantages to be gained in human health would make it well worth while to overcome these difficulties. Meanwhile, the staff of life remains a broken reed!