As one considers the wonderful diversity of animal life – my Standard Natural History speaks of “an almost awe-inspiring variety of form and size and coloration” – one naturally asks how long it takes all of these different animals to die of hunger. Happily, physiologists have been gathering experimental answers to this question for some 150 years. To start at the smaller end of things, for instance, hawk moth larvae (Manduca sexta) tend to die after 3 days without food, the house cricket (Achetes domesticus) after 5 days, and the Madagascar hissing cockroach (Gromphadorhina portentosa) after 52 days. These numbers, I should say, are measures of LT50: that is, the “lethal time” at which 50% of the individuals participating in the experiment are dead. Not that LT50 simply increases with size. Among bumble bees (Bombus impatiens), for instance, the smaller nursing bees apparently last longer than their larger foraging sisters.
Of course there is still a great deal to learn. Even the modest puzzle thrown up by the differential death-rates of those 1,432 bees that starved in the last-mentioned experiment shows that “there is a need for additional comparative studies of starvation physiology among many key groups of vertebrates and insects”. The trouble is, as the author of the multi-insect study says, there are “ethical concerns” associated with “starving vertebrate animals to death”. In general, therefore, the experiments have to be based on “sub-lethal periods of fasting”. His own study of various snakes, for instance (vipers, boa constrictors, pythons, rattlesnakes and others, a hundred in all), had them fasting for “sub-lethal periods” of 56, 112, and 168 days. Not that they survived the research – as we know, almost no animals in laboratories do – but they didn’t suffer what the author calls “starvation-induced mortality”. They died in some more “ethical” way.
The limitations imposed on research nowadays by these scruples may partly explain why the less inhibited work done in this subject a long time ago is still regularly cited: for instance, the pioneering work of Charles Chossat (published in 1843 as Recherches expérimentales sur l’inanition). Those, after all, were the days when it could safely be assumed that “no student of science would, as a student of science, do that which was not worthy of him”: so said Sir William Gull, physician to Queen Victoria, adding that cruelty laws were “made for the ignorant, and not for the best people in the country”. If a scientist was doing it, it was ipso facto ethical. And besides, as another medical scientist of the period said, being starved by Chossat or by any other agency involved “very little suffering”. (Being frozen to death was even better – “the reverse of painful”, he said – so that’s evidently the way to go.)
Generations of cats, dogs, rabbits, mice, pigeons, frogs, and others went on testing this claim, and their miserable experiences are still drawn on in modern studies, now that some better reason than merely finding things out has to be produced to justify “total fasting”, at least for the larger animals. Not that such reasons can’t readily be found or at least evoked: I note, for instance, a 1975 paper on the differential fasting to death of fat and thin mice, which modestly but crucially claims for itself “the potential of applicability of [these] findings to man”.
But it’s doubtful whether the starving of other animals has ever been of very significant ‘applicability to man’. After all, this is a branch of medical science in which there has always been plentiful human data available. Another classic of the subject, Francis Benedict’s A Study of Prolonged Fasting (1915), follows one human volunteer through a 31-day fast in minutest detail for over 400 pages. The clarity of its analysis is, of course, greatly assisted by the voluble co-operation of the volunteer. In fact the book, though replete with measurements of various kinds, reads at times like a novel, the starver himself being a distinct individual (as indeed all animals necessarily are, whether we happen to notice it or not).
In Benedict’s time, fasting was even being practised as a form of entertainment. One of the short stories of Franz Kafka describes the experiences of one such ‘hunger artist’ (‘Ein Hungerkünstler’, 1922). The most famous of these practitioners was Giovanni Succi, whom Benedict had actually considered employing (but he cost too much). Although, in his capacity as a research subject, Succi was primarily the property of a Florentine scientist, Professor Luigi Luciani, he performed internationally, and during a fast in London, so the Times reported in 1890, “he has been visited by many gentlemen of the medical profession, by whom his feat is regarded with much interest … important physiological deductions may be made from the experiment.” (The illustration shows Succi being visited by scientists during an earlier American tour.)
Another performer at the same London venue (the Westminster Aquarium) was called ‘Monsieur Jaques’, and he brought along his own applied research in the form of a herbal powder. This powder, he claimed, even in tiny quantities could on its own sustain life, and had indeed done so at the town of Belfort while it was besieged during the Franco-Prussian War of 1870-1. If there was some charlatanism mixed up in all this, then it was the business of physiologists to separate the science from the showmanship (as indeed some of them did), for there was knowledge to be found here of much more immediate importance “to man” than could be supplied by making pigeons or rabbits starve.
Fasting as a performance has long since gone out of fashion (though there was a reprise of sorts by the magician David Blaine in 2003). But human starvation, endured purposefully or not, has continued to provide its own data. Death by starvation in the U.K. usually entails an inquest and post-mortem: invariably so if it happens in prison – through hunger strike, in other words. There must therefore exist very many records of this sort. I notice a United Nations University report on starvation from the 1990s which makes use of just this sort of data, including information about hunger strikes of prisoners in Northern Ireland in the 1980s. Such a report to the U.N. would necessarily be aiming to provide thoroughly usable conclusions. (Even here, Chossat and his disciples put in an appearance, with their species mortality lists, as some sort of comparative back-up to the human material.)
However, starvation research of the kind instanced at the start of this piece has very little reference to medical usefulness: it’s a branch of zoology, a contribution to our knowledge of nature, answering the question I started with. Conditional on the ethical restraints mentioned, it’s free to grow as it will, and it does indeed demonstrate how growth works in such academic subjects. Each study raises new questions and calls for further research. Revisions, polite controversies, and synoptic reviews accumulate (already in 2010, a review of starvation studies had hundreds of papers to encompass). In time the subject becomes a sort of profession in itself, with its own conferences, authorities, jargon, journals, and honoured history (enter Chossat again). For you’ve scarcely broken ground when you simply starve a Madagascar hissing cockroach or a rattlesnake: you must go on to complicate the scene with other types of stress, add or withhold water, make the fast sustained or intermittent, start with fat or thin subjects or both (we’ve already noticed that). As a witness before a House of Representatives committee on vivisection once remarked, “you’d be surprised what professors and some students can think up”.
But a hawk moth larva, at least, or a house cricket, these don’t feel pain? Lest the question itself should sound like an invitation to fascinating new research, I shall put it another way: do they mind starving? To this we already have the answer because, as experimenters in starvation know well, precautions have to be taken against cheating, even among such innocents: they’ll eat their own excrement, or bedding, or each other, rather than starve honourably in the cause. So yes, even these have the urge to go on living, as we humans do, as all animal life does.
When a scientist alludes to “the ethical concerns of starving vertebrate animals to death”, he makes even morality sound like a technical matter, another aspect of the laboratory scene, something checked by glancing over one’s shoulder. No doubt it usually is just that, but it ought rather to be part of his or her own mentality. It would be much more convincing if the scientist said “we wouldn’t want to do that.” They might then set themselves to thinking up ways of studying life which don’t involve destroying its denizens, even these slightest of them. That would begin to answer Tony Benn’s question “Where is your moral teaching in science?” [see blog for 21 November, 2016] Meanwhile the moral teaching, the ethical motive, have to be urged upon the life sciences in the way they always have been over the last 150 years: that is, from outside. And in this particular case, one small thing which can be done now is to sign the following petition remonstrating against the starvation studies presently conducted at St Mary’s University of San Antonio in Texas: https://www.peta.org/action/action-alerts/rats-starvation-experiment-st-marys-university/?utm_campaign=051217%20peta%20e-news&utm_source=peta%20e-mail&utm_medium=e-news
Notes and references:
The insect study: Marshall D. McCue et al, ‘How and why do insects rely on endogenous protein and lipid resources during lethal bouts of starvation? A new application for C-breath testing’, PLoS One, 2015, 10(10). The bumble-bee study: M.J.Couvillon and A.Dornhaus, ‘Small worker bumble bees (Bombus impatiens) are hardier against starvation than their larger sisters’, Insectes Soc., May 2010, 57(2). The snake study: Marshall D. McCue, ‘Fatty acid analyses may provide insight into the progression of starvation among squamate reptiles’, Comparative Biochemistry and Physiology A: Molecular and Integrative Physiology, Oct. 2008, 151(2) The mouse study: G.S.Cuendet et al, ‘Hormone-substrate responses to total fasting in lean and obese mice’, American Journal of Physiology, Jan.1975, 228(1). The 2010 review: Marshall D. McCue, ‘Starvation physiology: reviewing the different strategies animals use to survive a common challenge’, Comparative Biochemistry and Physiology A: Molecular and Integrative Physiology, May 2010, 156(1)
Sir William Gull and Dr Francis Sibson are quoted from their evidence to the Cardwell Commission in 1876: Report of the Royal Commission on the Practice of Subjecting Live Animals to Experiments for Scientific Purposes, HMSO, 1876, pp.265-7, and 237.
Quotation and other details about the hunger artists are taken from reports in the London Times on 24 March, 12 April, and 23 June 1890.
The UN report: M.Elia, ‘Effect of starvation and very low calorie diets on protein-energy relationships in lean and obese subjects’, published in Protein-Energy Interactions, ed. Scrimshaw and Schürch, 1992, accessible online at http://archive.unu.edu/unupress/food2/UID07E/UID07E11.HTM
The evidence to the House of Representatives committee investigating the treatment of animals used in research, 1962, is quoted by John Vyvyan in The Dark Face of Science, London (Michael Joseph), 1971, p.188.
The two wood-engravings: ‘Waiting for Death’ (1832), by Thomas Bewick, shows a horse at the end of its career of usefulness to humans, turned out, as Bewick notes, “to starve of hunger and of cold”; the picture of Succi and medical company is from the Christian Herald (New York 1886), courtesy of Internet Archive.