FAT: It's Not What You Think
Version of Record online: 2 JUN 2009
© 2009 The Authors. Journal Compilation © 2009 Public Health Association of Australia
Australian and New Zealand Journal of Public Health
Volume 33, Issue 3, pages 297–298, June 2009
How to Cite
(2009), FAT: It's Not What You Think. Australian and New Zealand Journal of Public Health, 33: 297–298. doi: 10.1111/j.1753-6405.2009.00394.x
- Issue online: 2 JUN 2009
- Version of Record online: 2 JUN 2009
By 2008 Paperback 214 pages with index RRP $27.95 ISBN 978-1-59102-612-9. Published by Prometheus Books , New York ,
Reviewed by Joseph Proietto
University of Melbourne, Department of Medicine, Austin Health, Victoria
This book, whose aim is to answer all of the reader's questions on fat, is an interesting mix of conspiratory theory, science and pseudoscience. The author is an American science writer with many years experience. The book is logically set out and contains some well written passages demystifying such topics as what a trans fat is; what it means when a fat is saturated or unsaturated; how fat is digested and more. It correctly blames genes for much of the obesity that we see. However, in my view, the book is spoiled by inaccuracies, and paranoia not to mention the failure of making the book relevant for anyone outside the US.
First the inaccuracies; in no less than three places, it is claimed that fat cells (not fat tissue) produce macrophages, oestrogen and cortisol, none of which is correct. Apparently cholesterol is so important to our bodies (a true statement) that “….the liver and other organs, manufacture cholesterol from protein, carbohydrate and fats.” In reality, Konrad Bloch won a Nobel Prize for elucidating the cholesterol synthesis pathway which involves 3 Hydroxy-3-methylglutaryl coenzyme A, its conversion to mevalonic acid by the rate limiting enzyme of cholesterol synthesis (and the target of the statin drugs), conversion to farnesyl pyrophosphate then to squalene and ultimately to the steroid ring of cholesterol.
The discussion of insulin resistance is a little wide of the mark. Firstly, it is stated that insulin resistance is “… triggered by genes, sugar or a combination of both.” In fact, genetic causes of insulin resistance are rare and glucose mostly impairs its own transport rather than the action of insulin. There is now general agreement that the major cause of insulin resistance is excess fat, a strange omission in a book on fat! In the same section, it is stated (correctly) that insulin stimulates lipogenesis (the synthesis of fat) and inhibits lipolysis (the breakdown of fat), but then the author says, “Thus, insulin resistant people are good at converting food to fat.” However, if we follow this logic, the opposite should be true. In someone in whom insulin does not work, the synthesis of fat should be reduced and the breakdown of fat should be enhanced making it more difficult to store fat!
The paranoia begins in the introduction and continues in chapter 7. Apparently cholesterol is not harmful, and the idea that it is, is pushed by the evil drug companies who promote their cholesterol lowering drugs by bribing nearly every doctor. The clear impression given in chapter 7 is that high cholesterol is beneficial. Low cholesterol is associated with increased risk of stroke and since the brain has a lot of fat in it, cholesterol must be good for it. Unfortunately, this ignores the results of many studies showing that statins reduce the risk of heart attack in both primary and secondary prevention. The author makes the point that there is little evidence that dietary cholesterol is harmful. This may be true, as in many, hypercholestrolaemia is of endogenous origin, hence the lean hypercholesterolaemic patient. But even if it is true that dietary cholesterol does not increase the incidence of heart attacks, it is not logical to then extrapolate and say that cholesterol is not harmful. The statement that “…patients taking statin drugs often report serious side effects…” is simply not true as I can attest from my own practice. Statins can cause myopathy, but thankfully this side effect is not common.
A legitimate criticism on the way statins are used might be that they are often prescribed in the absence of an assessment of the patient's overall cardiovascular risk. This criticism is not made in the book, with the author preferring to attack the medical profession and suggesting that elevated cholesterol is beneficial.
Finally, all of the units in the book are in mg/dL with no values (in brackets) in mmol/l, the units used in many parts of the world. This requires the professional reader to make the conversion and confuses the lay reader.
Is summary, the book has some useful information on the nature of fat but overall cannot be considered to be an accurate and balanced discussion on the topic.