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Yeast as food
30 public health field ; a shortened training course is now being
considered. At the end of the suggested two years the probationer would take a qualifying examination and be able to earn wages, though she would be required to spend another six months as a staff nurse under supervision before obtaining a licence to practise. T h i s six months would count towards the period of further training and experience required for specialisation ;n public health, teaching, midwifery, and other fields. A shortened nursing curriculum might be expected to do away with the need for the special category of " assistant nurse," established under the 1943 Act. Some alteration of the constitution of the General Nursing Council is considered necessary, and the comment is made that no attempt so far has been made to integrate the functions of the Council and of the Central Midwives Board with the Division of Nursing of the Ministry of Health. Many suggestions are made in the memorandum for improving the conditions under which nurses do their work. Superannuation arrangements should be interchangeable between all forms of nursing service, whether undertaken in the employment of a local authority or a voluntary body. Hospital nurses, whether in training or fully qualified, should have a legal contract of~service, with right of a~peal against dismissal. Marriage should not be a barrier to continued service, and to make the service more attractive to married women an eight-hour shift basis should be arranged; this would also mean better attention for patients. Salary scales should be brought more into line with the salaries earned by men and women in other professions. All overtime should be paid for. T h e r e should be better safeguards for the health of nurses, with detailed initial examinations and regular reexaminations. An adequate and appetising diet, with no preferential treatment for certain categories of hospital employees, is another requirement. Although for nurses in training a period of residence is probably desirable, once they are qualified they should be allowed to live where they please. Nurses' homes and hostels should be run by a specially appointed warden and a house committee of residents. Welfare officers should be appointed to look after the well-being and recreation of nurses and indeed of all hospital employees. Finally, Nurses Representative Councils, in the view of the S.M.A., should be set up in all institutions. T h e y should have wide terms of reference and should send members to the Hospital Committee, which ought to be representative of all grades of hospital workers. T h e Government publication underwrites much of what is in the S.M.A. memorandum, and in its note of urgency recognises the extreme seriousness of the present position. If new recruits cannot be obtained quickly, it is stated, " large numbers of people urgently requiring treatment will be unable to gain admission to hospital and many patien*s in hospital will not receive the attention they need . . . . T h e adequate staffing of the hospitals is an urgent national need . . . . It must be met."
Yeast as F o o d Since the introduction of machinery the mills of the millers have ground exceeding small, and by now every school-boy knows that this has helped to reduce the vitamin B content of the national diet. M u c h less familiar is the fact that the refinement of modern beer has h a d a similar effect, and perhaps a medical sociologist of the future may attribute the increased consumption of beer to an instinctive recognition of this fact. T h e mead and beer our ancestors drank had plenty of yeast cells in the dregs, and the glass-bottomed tankard made it easy for the drinker to see that no dregs were left behind. Deficiency of vitamins in African natives has been attributed to the introduction of sophisticated food and drink, for they, too, used to get their B vitamins from the yeast of their fermented drinks. Yeast has now come back into its own in the form of tablets and a well-known proprietary preparation; and the establishment of Colonial Food Yeast, Ltd., under Governmefit auspices, is yet another attempt to restore to diet what has been taken away from it. It is in a certain sense a paradox that this return to the natural is the outcome o f the refinement of the chemist's technique, and the results of
PUBLIC HEALTH, December, 1945 this are now s e t down in a most interesting memorandum issued by the Medical Research Council,* During the war of 1914-18 the Germans cultivated a strain of yeast (Torula) which produced little alcohol and grew well on a sugar medium containing nitrogen in inorganic form. T h e yeast was meant to provide protein for the German diet. T h e growth of yeast cells in media containing sugar, molasses, or hydrolysed celluloses, with nitrogen in inorganic form, was a useful biological trick for changing energy foods into protective foods--that is, into protein and vitamins. This way of fortifying tropical d i e t with valuable nutrients was recommended by the League of Nations Technical Commission on Nutrition in 1938. A year later the Agricultural Research Council considered the possibility of manufacturing yeast for feeding livestock. In 1941 the Government Committee on Scientific Food Policy also went into the question of producing yeast for feeding man, and in the same year the Ministry of Food set up a company for turning out food yeast at the rate of 10,000 tons a year. This company has now been superseded by Colonial Food Yeast, Ltd., in Jamaica, where Torula utilis is grown on the waste prodracts from the sugar industry. Brewers' yeast, Saccharomyces cerevisiae, when recovered from brewers' vats, has too bitter a taste. During the past four or five years food yeast has been investigated from the standpoints of (1) composition and vitamin content; (2) nutrition as determined by animal experiments; and (3)nutritional trials on human subjects. T h e tables in the M.R.C. Memorandum show that food yeast is a good source of protein and " a first-rate source of the B group of vitamins." T h e yeast proteins were found to possess a biological value approaching that of milk proteins, but prolonged tests showed that they were inferior to casein and to the mixed proteins of wheat in the proportions occurring naturally in the whole grain; this inferiority was found to be due to a deficiency of the essential amino-acid, methionine. But when yeast is added to a diet consisting mainly of cereals, its supplementary value is equal to that of milk proteins. In trials on human subjects it was found that a quarter of an ounce of a food yeast could be taken daily without upsetting digestion, and although this increases the amount of protein in the diet by only 3 grammes, it is thought that the supplementing action of the amino-acids in yeast proteins greatly improves the quality of the diet, especially of the proteins of cereals, of which most " p o o r " diets are largely composed. A hundred airmen were given 8 grammes of food yeast daily for ten days, and no ill-effects were observed. Yeast was added to whole-wheat flour to the extent of 5~/o on a dry weight basis, and to white flour to the o/ without affecting flavour. A striking improveextent of 2/o, ment in patients with deficiency of the B2 vitamins has been obtained by giving food yeast in Nigeria---4 to 7 grammes daily for a period of five to seven weeks ; and gingival disease in children from Gibraltar responded well to similar treatment. Food yeast, therefore, would seem to be a valuable and cheap method of supplementing a vitamin B deficient diet and of treating B-deficiency disorders. It would also seem to be a cheap way of supplementing the protein-deficient diets of backward peoples. But from all this work one cannot escape the reflection that the human race has grown remarkably careless about one way of securing the survival of the human species--namely, by feeding itself properly. T h e rest of the animal kingdom seems to manage these things better.
Wing-Commander C. J. Hackett has been appointed Dire~or of the Wellcome Museum of Medical Science in succession to Dr. S. H. Daukes who has been responsible tor the development of this museum during the last 26 years. "Dr. Hackett, who was a Research Fellow in Tropical Medicine of the Medical Research Council and has done important work on yaws and other tropical diseases, will take up his new appointment as soon as he has been released from the Royal Air Force. * Food Yeast : A Survey of its Nutritive Value. By the Accessory Food Factors Committee. M.R.C. War Mem. No. 16. 1945. H.M.S.O. Price 3d. net.
considered. At the end of the suggested two years the probationer would take a qualifying examination and be able to earn wages, though she would be required to spend another six months as a staff nurse under supervision before obtaining a licence to practise. T h i s six months would count towards the period of further training and experience required for specialisation ;n public health, teaching, midwifery, and other fields. A shortened nursing curriculum might be expected to do away with the need for the special category of " assistant nurse," established under the 1943 Act. Some alteration of the constitution of the General Nursing Council is considered necessary, and the comment is made that no attempt so far has been made to integrate the functions of the Council and of the Central Midwives Board with the Division of Nursing of the Ministry of Health. Many suggestions are made in the memorandum for improving the conditions under which nurses do their work. Superannuation arrangements should be interchangeable between all forms of nursing service, whether undertaken in the employment of a local authority or a voluntary body. Hospital nurses, whether in training or fully qualified, should have a legal contract of~service, with right of a~peal against dismissal. Marriage should not be a barrier to continued service, and to make the service more attractive to married women an eight-hour shift basis should be arranged; this would also mean better attention for patients. Salary scales should be brought more into line with the salaries earned by men and women in other professions. All overtime should be paid for. T h e r e should be better safeguards for the health of nurses, with detailed initial examinations and regular reexaminations. An adequate and appetising diet, with no preferential treatment for certain categories of hospital employees, is another requirement. Although for nurses in training a period of residence is probably desirable, once they are qualified they should be allowed to live where they please. Nurses' homes and hostels should be run by a specially appointed warden and a house committee of residents. Welfare officers should be appointed to look after the well-being and recreation of nurses and indeed of all hospital employees. Finally, Nurses Representative Councils, in the view of the S.M.A., should be set up in all institutions. T h e y should have wide terms of reference and should send members to the Hospital Committee, which ought to be representative of all grades of hospital workers. T h e Government publication underwrites much of what is in the S.M.A. memorandum, and in its note of urgency recognises the extreme seriousness of the present position. If new recruits cannot be obtained quickly, it is stated, " large numbers of people urgently requiring treatment will be unable to gain admission to hospital and many patien*s in hospital will not receive the attention they need . . . . T h e adequate staffing of the hospitals is an urgent national need . . . . It must be met."
Yeast as F o o d Since the introduction of machinery the mills of the millers have ground exceeding small, and by now every school-boy knows that this has helped to reduce the vitamin B content of the national diet. M u c h less familiar is the fact that the refinement of modern beer has h a d a similar effect, and perhaps a medical sociologist of the future may attribute the increased consumption of beer to an instinctive recognition of this fact. T h e mead and beer our ancestors drank had plenty of yeast cells in the dregs, and the glass-bottomed tankard made it easy for the drinker to see that no dregs were left behind. Deficiency of vitamins in African natives has been attributed to the introduction of sophisticated food and drink, for they, too, used to get their B vitamins from the yeast of their fermented drinks. Yeast has now come back into its own in the form of tablets and a well-known proprietary preparation; and the establishment of Colonial Food Yeast, Ltd., under Governmefit auspices, is yet another attempt to restore to diet what has been taken away from it. It is in a certain sense a paradox that this return to the natural is the outcome o f the refinement of the chemist's technique, and the results of
PUBLIC HEALTH, December, 1945 this are now s e t down in a most interesting memorandum issued by the Medical Research Council,* During the war of 1914-18 the Germans cultivated a strain of yeast (Torula) which produced little alcohol and grew well on a sugar medium containing nitrogen in inorganic form. T h e yeast was meant to provide protein for the German diet. T h e growth of yeast cells in media containing sugar, molasses, or hydrolysed celluloses, with nitrogen in inorganic form, was a useful biological trick for changing energy foods into protective foods--that is, into protein and vitamins. This way of fortifying tropical d i e t with valuable nutrients was recommended by the League of Nations Technical Commission on Nutrition in 1938. A year later the Agricultural Research Council considered the possibility of manufacturing yeast for feeding livestock. In 1941 the Government Committee on Scientific Food Policy also went into the question of producing yeast for feeding man, and in the same year the Ministry of Food set up a company for turning out food yeast at the rate of 10,000 tons a year. This company has now been superseded by Colonial Food Yeast, Ltd., in Jamaica, where Torula utilis is grown on the waste prodracts from the sugar industry. Brewers' yeast, Saccharomyces cerevisiae, when recovered from brewers' vats, has too bitter a taste. During the past four or five years food yeast has been investigated from the standpoints of (1) composition and vitamin content; (2) nutrition as determined by animal experiments; and (3)nutritional trials on human subjects. T h e tables in the M.R.C. Memorandum show that food yeast is a good source of protein and " a first-rate source of the B group of vitamins." T h e yeast proteins were found to possess a biological value approaching that of milk proteins, but prolonged tests showed that they were inferior to casein and to the mixed proteins of wheat in the proportions occurring naturally in the whole grain; this inferiority was found to be due to a deficiency of the essential amino-acid, methionine. But when yeast is added to a diet consisting mainly of cereals, its supplementary value is equal to that of milk proteins. In trials on human subjects it was found that a quarter of an ounce of a food yeast could be taken daily without upsetting digestion, and although this increases the amount of protein in the diet by only 3 grammes, it is thought that the supplementing action of the amino-acids in yeast proteins greatly improves the quality of the diet, especially of the proteins of cereals, of which most " p o o r " diets are largely composed. A hundred airmen were given 8 grammes of food yeast daily for ten days, and no ill-effects were observed. Yeast was added to whole-wheat flour to the extent of 5~/o on a dry weight basis, and to white flour to the o/ without affecting flavour. A striking improveextent of 2/o, ment in patients with deficiency of the B2 vitamins has been obtained by giving food yeast in Nigeria---4 to 7 grammes daily for a period of five to seven weeks ; and gingival disease in children from Gibraltar responded well to similar treatment. Food yeast, therefore, would seem to be a valuable and cheap method of supplementing a vitamin B deficient diet and of treating B-deficiency disorders. It would also seem to be a cheap way of supplementing the protein-deficient diets of backward peoples. But from all this work one cannot escape the reflection that the human race has grown remarkably careless about one way of securing the survival of the human species--namely, by feeding itself properly. T h e rest of the animal kingdom seems to manage these things better.
Wing-Commander C. J. Hackett has been appointed Dire~or of the Wellcome Museum of Medical Science in succession to Dr. S. H. Daukes who has been responsible tor the development of this museum during the last 26 years. "Dr. Hackett, who was a Research Fellow in Tropical Medicine of the Medical Research Council and has done important work on yaws and other tropical diseases, will take up his new appointment as soon as he has been released from the Royal Air Force. * Food Yeast : A Survey of its Nutritive Value. By the Accessory Food Factors Committee. M.R.C. War Mem. No. 16. 1945. H.M.S.O. Price 3d. net.