Dietary Bran Fibre Increases Cancer Risk

Part 4: Men only?

Professor David Southgate is a world-renowned expert on dietary fibre. He concludes that the effects of excessive intakes of dietary fibre on calcium, iron and zinc absorption would be particularly undesirable for infants, children and young adolescents, and recommends that dietary fibre intakes in those groups should be separated from those for the general adult population and given on a body-weight basis. ⁽⁴⁷⁾ To them should be added pregnant women and post-menopausal women whose mineral needs are greater and who should also be protected from excessive consumption of fibre.

The advice given by dieticians, nutritionists and doctors appears to include no caveats concerning age, sex or body weight. Indeed, the impression given by them all is that we should all eat as much fibre as we can tolerate. The British Medical Association in its publication The Slimmers' Guide , even recommends bran as a good source of calcium! ⁽⁴⁸⁾ Not unnaturally, the makers of All-bran and similar breakfast cereals, and wholemeal breads bombard us via television advertisements stressing the goodness contained in their products by virtue of the high bran content. Yet the only members of the population who may eat these in any quantity with relative impunity are adult men.

Conclusion

What we have then is evidence that consumption of fibre — and bran in particular — may be hazardous.

There are conflicting reports, some of which implicate fibre as increasing the risk of the cancers it is supposed to protect against. There is also a similar danger of malnutrition in the many sections of society.

It is unlikely that eating bran is of benefit to any section of society. There is a limit under which bran may not be harmful — but we have no ready way to know what that limit is. Therefore, it is much safer for you to avoid bran than to try to gauge what your safe limit might be. And if you do suffer from constipation, you would be better advised to drink more water. A minimum of four pints a day should do it.

References

47. Southgate D A T. Minerals, trace elements and potential hazards. Am J Clin Nutr. 1987; 45: 1256.
48. BMA. The Slimmers' Guide . Family Doctor Publications, 1988. Latimer Trench & Co Ltd. Plymouth.

Last updated 26 March 2001