DIETARY FIBRE: FOOD OR FETISH? SIR,-Among the food components involved in the current campaign for "healthier eating" dietary fibre is unique since while we are being told to eat less fat, red meat, sugar, total calories, and salt, our fibre intake, as contributed by brown bread, breakfast cereals, vegetables, and fruit, should, we are told, be substantially increased. There is no novelty in this "fibrophilia". In the 1930s Arbuthnot Lanel promoted a "New Health" movement in which he urged, inter alia, that plenty of roughage should be included in the diet. Efficient defaecation and the passage of stools promptly after every substantial meal carried the hope that the incidence of intestinal disease would thereby be reduced. Thirty years later Burkitt suggested that the freedom of Africans from intestinal cancer might be related to their subsistence on coarse cereal foods, which promoted the frequent excretion of copious, loose stools. Lately, however, this theory has been questioned, with the suggestion that low cancer rates in East Africans may be due to high early death rates from other causes (so that many do not reach the age at which cancer incidence peaks in Europeans) and a growing scepticism in the United States that lack of fibre can cause cancer. Cancer apart, it seems beyond question that constipation has long been a nuisance and minor health hazard among developed populations. Memory, aided by the perusal of old advertisements, will summon up a parade of remedies mild or drastic, vegetable or mineral such as intestinal irritants, Epsom or Glauber’s salts, charcoal, liquid paraffin, enemas, and lavage. If a liberal intake of dietary fibre can make most of these treatments obsolete is that not ample justification for singling out this factor as being outstanding in its health-giving potential? Unfortunately things are not quite so simple. Praise for the virtues of fibre in the education of the general public should not be allowed to obscure the fact that fibre is by no means indispensable as a dietary component. No more material contribution is made by fibre to body building or energy production than could be made by an equal amount of finely chopped toilet paper. Moreover, there is always the danger of serious miscarriages in the chain of information coming down from expert committees to the unqualified people who organise press or television programmes or who draw attractive posters. Such a miscarriage must surely account for the title of the recent television series You are What you Eat. Presumably derived from the truism Der Mensch ist er isst, attributable to the philosopher Feuerbach (1804-72), this slogan was chanted repeatedly throughout the series, interspersed by dictory advice, gravely delivered by learned experts. But one impor- tant point seems to have been overlooked. In regard to dietary fibre, the food factor apparently to be prized above all others, "you" are certainly not what you eat, and the slogan so vigorously chanted should surely have been:

"Most of what you eat turns into you,

But dietary fibre just goes through."

Elsewhere on a television background poster depicted a strong man’s bulging biceps accompanied by the caption "fibre", thus suggesting that the muscle fibres of the human body are directly derived from an indigestible fraction of the diet. Intentionally or not there seems to have been an unhappy confusion between "brawn" and "bran". So is dietary fibre a food or just a fetish? Its value as a food is virtually zero. Whether or not it can justly be counted as a fetish ("something regarded with irrational reverence") requires deeper thought. A sensible balance may perhaps be reached by regarding fibre (roughage) as a bland natural agent that when consumed in moderate amounts facilitates the passage of food and solid waste products along the intestinal tract. In this limited role the fibre seems entirely praiseworthy. If through excessive, media-fanned enthusiasm, however, reasonable appreciation of the virtues of fibre should develop into a fetish, the ultimate effects could be unfortunate. For example, modern mothers of growing families, perhaps already obsessed with the virtues of slimming, could devote an excessive fraction of their limited household budget to the purchase of much advertised and expensive fibre-rich biscuits, breakfast foods, and out-of season greenery. With the balance tipped from nutrients to fibre, such pampered children could well lag behind in growth.

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THOMAS MOORE