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DIET AND CORONARY THROMBOSIS
384 Death of the foetus removes the anabolic stress, but leaves the damaged placenta. The contractions of labour may disseminate debris from this, precipitating eclampsia.
We
taught that women Certainly they must
in pregnancy need extra have adequate protein, vitamins, calcium, and iron. But, because of foetal anabolism, the pregnant woman is like a stove with the damper pushed in ; less, not more, " fuel " is required. She must not consume too much carbohydrate, which (because of difficulty in oxidation or combustion) is not very suitable for a " damped-down stove." Only when all mothers, doctors, and midwives appreciate this shall we reduce toxsemia and eclampsia to near vanishing point ; at present they rank as Public Enemy Number One in British obstetrics. K. D. SALZMANN.
food.
are
PAINFUL EXPERIMENTS ON ANIMALS
Sm,—Your report of July 27 (p. 195) of the recent House of Lords debate referred to the statement made by Lord Chesham, replying to Lord Dowding, that "many cases of cruelty had, however, been brought under the Protection of Animals Act, 1911, but no successful prosecution had ever been brought under it against anyone who held a vivisection licence." For the accuracy of the record, may I refer to the fact that in 1946 there was such a conviction. Replying to a question in connection with this case in the House of Commons on Oct. 21, 1946, the then Home Secretary, Mr. Chuter Ede (see Hansard for that date) said that the person convicted " holds the certificates under the Act of 1876 authorising him to conduct certain experiments with a view to the study of nervous disease in man or animals. He was convicted not for any offence in the performance of these eceperiments, but under the Protection of Animals Act, 1911, for causing unnecessary suffering by keeping in a compound too many cats while they were suffering from distemper." The National Anti-Vivisection Society, London, S.W.1.
W. RISDON.
DIET AND CORONARY THROMBOSIS
SiR,-Without prejudice
to the view that
non-dietary
factors may be of considerable importance, it seems to that Professor Yudkin’s data (July 27) are not altogether incompatible with a relatively simple correlation between diet and coronary mortality. It seems that if the total fat intake is less than about 100 g. a day the mortality is low, irrespective of the kind of fat. If the total fat intake exceeds 100 g. a day there may be a high mortality from coronary disease depending on whether the diet contains a protective factor. This factor is apparently associated with certain vegetable and marine oils including margarine. The countries for which Professor Yudkin gives statistics may then be divided into three groups. Using the numbering system given in his article, countries 12 to 15 fall into the low-fat category and consequently have a low coronary mortality. At the other extreme, øountries 1 to 5 have a high fat intake and a low margarine consumption and thus have a high coronary mortality. Finland (4) has a total fat intake not greatly in excess of 100 g. a day, but falls into this category because of the low proportion of margarine or vegetable fat. The United Kingdom (6) has a relatively high coronary mortality as might be expected from a high total fat intake and a moderate margarine intake. Inevitably, when dealing with statistics of this kind, there is a fairly large middle group-countries 7 to 11 with moderate coronary mortality and no dietary extremes, the relatively high fat intake in this group being balanced by a fairly high intake of vegetable fat or margarine. It would be interesting to know the nature of the vegetable fat other than margarine consumed in some me
’
of the countries mentioned. For example, the United States (1) has a relatively high vegetable-fat figure, but a low margarine intake compared with Norway in which the margarine intake is high and the vegetable. fat figure is low. Thus, contrary to what has generally been supposed, margarine would appear to have a significant amount of the protective factor. There is some evidence that the protective factor i Professor Yudkin the essential fatty acids (E.F.A.). himself has pointed out that margarine may have an The type of E.F.A. content five times that of butter.1 oil used for the preparation of margarine varies consider. ably from country to country and there may be a variation in the content of the protective factor. If margarine is, in fact, the hero and not the villain of the piece the prophylaxis of coronary disease by dietary means may be less drastic than some have envisaged. R. COBB.
:
BLOOD-COUNTING MACHINE
Sm,—Reading the correspondence on this subject in your issue of Aug. 10 from the viewpoint of one instructed in and convinced of the fallacies of colour. index h2ematology, I share Dr. Shillitoe’s downrightd attitude to the red-cell count and envy Dr. Watson. B Williams the number of technicians he has to do his ever-increasing numbers of counts. In this hospital, in addition to 250 antenatal screening haemoglobins (which arrive in Wintrobe bottles), the’number of individual-patient examinations and follow-ups dealt with in the cytological section averages 800 per month, and nearly all these are taken directly from the patient by the technical staff (including nearly 17% from practitioners’ direct-service patients). Out of this total, hsemoglohin estimations are done in 664 cases. 264 white-cell counts are done. Blood-films are made in 712 cases (since every hamo globin and/or white-cell count requires a film). The rest of the examinations are : various (e.g., pleural and seminal fluids) 3%, and E.s.R.s alone 8%. This work is done by 21/2 tech. nicians (as well as the prothrombins) and the films are read by the pathologist.
With the commercial advent of the red-cell-counting we have had to decide whether or not to ask for one. Although we used to do some red-cell counts at clinical request, we have not* seen advantage from these ; and much confusion has arisen through colour. index calculations. Of course, we do not know whether we would not be better off with a really accurate red. cell count plus haemoglobin plus film survey. We think we might be but, as Dr. Watson-Williams points out, we would need at least one skilled technician to operate and service the machine and cope with the numbers of counts. To us that would mean at least one extra technician for the same service we give at present. Machines and technicians cost a lot, and where I differ from Dr. Watson-Williams, therefore, is ina present assessment of the likelihood of saving the cost of the machines. We feel we will have to wait until some larger laboratory equipped with money, time, and staff can really prove the benefits of having numerous red-cell counts (the white-cell counts do not matter so much,
machines,
and easy to do, not requiring a high degree of accuracy, and being readily checked by film survey). After film reading we believe all films should be kept 5 years.
being quick
must
have
been
reliable (e.g., May-GranwaldFilms are then packed back in the boxes in which they were sold, with microil left on, to avoid fading, scratches, and dust. A patient-follow-up file should be kept on at least a 5-year basis, with another file for special long-terms cases and, for example, leukaemias. Looking over the film," as Meynell puts it, takes, whell one’is learning, a long time for each film (particularly to establish which are really in all respects normal) and, when learning, this has to be done without reference to clinical
Staining
Giemsa, not Leishman).
"
1. Lancet, 1956, i, 506.
We
taught that women Certainly they must
in pregnancy need extra have adequate protein, vitamins, calcium, and iron. But, because of foetal anabolism, the pregnant woman is like a stove with the damper pushed in ; less, not more, " fuel " is required. She must not consume too much carbohydrate, which (because of difficulty in oxidation or combustion) is not very suitable for a " damped-down stove." Only when all mothers, doctors, and midwives appreciate this shall we reduce toxsemia and eclampsia to near vanishing point ; at present they rank as Public Enemy Number One in British obstetrics. K. D. SALZMANN.
food.
are
PAINFUL EXPERIMENTS ON ANIMALS
Sm,—Your report of July 27 (p. 195) of the recent House of Lords debate referred to the statement made by Lord Chesham, replying to Lord Dowding, that "many cases of cruelty had, however, been brought under the Protection of Animals Act, 1911, but no successful prosecution had ever been brought under it against anyone who held a vivisection licence." For the accuracy of the record, may I refer to the fact that in 1946 there was such a conviction. Replying to a question in connection with this case in the House of Commons on Oct. 21, 1946, the then Home Secretary, Mr. Chuter Ede (see Hansard for that date) said that the person convicted " holds the certificates under the Act of 1876 authorising him to conduct certain experiments with a view to the study of nervous disease in man or animals. He was convicted not for any offence in the performance of these eceperiments, but under the Protection of Animals Act, 1911, for causing unnecessary suffering by keeping in a compound too many cats while they were suffering from distemper." The National Anti-Vivisection Society, London, S.W.1.
W. RISDON.
DIET AND CORONARY THROMBOSIS
SiR,-Without prejudice
to the view that
non-dietary
factors may be of considerable importance, it seems to that Professor Yudkin’s data (July 27) are not altogether incompatible with a relatively simple correlation between diet and coronary mortality. It seems that if the total fat intake is less than about 100 g. a day the mortality is low, irrespective of the kind of fat. If the total fat intake exceeds 100 g. a day there may be a high mortality from coronary disease depending on whether the diet contains a protective factor. This factor is apparently associated with certain vegetable and marine oils including margarine. The countries for which Professor Yudkin gives statistics may then be divided into three groups. Using the numbering system given in his article, countries 12 to 15 fall into the low-fat category and consequently have a low coronary mortality. At the other extreme, øountries 1 to 5 have a high fat intake and a low margarine consumption and thus have a high coronary mortality. Finland (4) has a total fat intake not greatly in excess of 100 g. a day, but falls into this category because of the low proportion of margarine or vegetable fat. The United Kingdom (6) has a relatively high coronary mortality as might be expected from a high total fat intake and a moderate margarine intake. Inevitably, when dealing with statistics of this kind, there is a fairly large middle group-countries 7 to 11 with moderate coronary mortality and no dietary extremes, the relatively high fat intake in this group being balanced by a fairly high intake of vegetable fat or margarine. It would be interesting to know the nature of the vegetable fat other than margarine consumed in some me
’
of the countries mentioned. For example, the United States (1) has a relatively high vegetable-fat figure, but a low margarine intake compared with Norway in which the margarine intake is high and the vegetable. fat figure is low. Thus, contrary to what has generally been supposed, margarine would appear to have a significant amount of the protective factor. There is some evidence that the protective factor i Professor Yudkin the essential fatty acids (E.F.A.). himself has pointed out that margarine may have an The type of E.F.A. content five times that of butter.1 oil used for the preparation of margarine varies consider. ably from country to country and there may be a variation in the content of the protective factor. If margarine is, in fact, the hero and not the villain of the piece the prophylaxis of coronary disease by dietary means may be less drastic than some have envisaged. R. COBB.
:
BLOOD-COUNTING MACHINE
Sm,—Reading the correspondence on this subject in your issue of Aug. 10 from the viewpoint of one instructed in and convinced of the fallacies of colour. index h2ematology, I share Dr. Shillitoe’s downrightd attitude to the red-cell count and envy Dr. Watson. B Williams the number of technicians he has to do his ever-increasing numbers of counts. In this hospital, in addition to 250 antenatal screening haemoglobins (which arrive in Wintrobe bottles), the’number of individual-patient examinations and follow-ups dealt with in the cytological section averages 800 per month, and nearly all these are taken directly from the patient by the technical staff (including nearly 17% from practitioners’ direct-service patients). Out of this total, hsemoglohin estimations are done in 664 cases. 264 white-cell counts are done. Blood-films are made in 712 cases (since every hamo globin and/or white-cell count requires a film). The rest of the examinations are : various (e.g., pleural and seminal fluids) 3%, and E.s.R.s alone 8%. This work is done by 21/2 tech. nicians (as well as the prothrombins) and the films are read by the pathologist.
With the commercial advent of the red-cell-counting we have had to decide whether or not to ask for one. Although we used to do some red-cell counts at clinical request, we have not* seen advantage from these ; and much confusion has arisen through colour. index calculations. Of course, we do not know whether we would not be better off with a really accurate red. cell count plus haemoglobin plus film survey. We think we might be but, as Dr. Watson-Williams points out, we would need at least one skilled technician to operate and service the machine and cope with the numbers of counts. To us that would mean at least one extra technician for the same service we give at present. Machines and technicians cost a lot, and where I differ from Dr. Watson-Williams, therefore, is ina present assessment of the likelihood of saving the cost of the machines. We feel we will have to wait until some larger laboratory equipped with money, time, and staff can really prove the benefits of having numerous red-cell counts (the white-cell counts do not matter so much,
machines,
and easy to do, not requiring a high degree of accuracy, and being readily checked by film survey). After film reading we believe all films should be kept 5 years.
being quick
must
have
been
reliable (e.g., May-GranwaldFilms are then packed back in the boxes in which they were sold, with microil left on, to avoid fading, scratches, and dust. A patient-follow-up file should be kept on at least a 5-year basis, with another file for special long-terms cases and, for example, leukaemias. Looking over the film," as Meynell puts it, takes, whell one’is learning, a long time for each film (particularly to establish which are really in all respects normal) and, when learning, this has to be done without reference to clinical
Staining
Giemsa, not Leishman).
"
1. Lancet, 1956, i, 506.