Salt, Diet and Health [Hardcover]

G. A. MacGregor (Author), H. E. de Wardener (Author)

Book Description

ISBN-10: 0521583527 | ISBN-13: 978-0521583527 | Publication Date: September 28, 1998

The deliberate and often well-camouflaged addition of excess salt to processed foods has momentous health consequences, comparable in nature to the well-documented risks of smoking tobacco. Should our processed food come with a government health warning? The authors of this book provide a compelling and forceful account of these complex issues, teasing out fact from fantasy, and casting light on some of the hidden forces working to manipulate and exploit the consumer. This scientific detective story unravels with startling clarity how the evidence for the prosecution has been obfuscated, misinterpreted and even denigrated by some of the powerful vested interests of the multi-billion dollar food industry. Along the way, the authors illuminate the rich history and mythology associated with salt, its symbolism and manifold socio-economic consequences, all illustrated with an entertaining and eclectic selection of historical and contemporary illustrations. On the one hand this is a book with profound implications for public health, and on the other it is an entertaining and instructive account of a part of our diet that is too easily taken for granted, and ignored at our peril.

Editorial Reviews

From The New England Journal of Medicine

How many of us would like our salaries paid in salt? Not these authors, for sure; but their opening chapters remind us with choice historical and biblical anecdotes of the economic imperatives that are mirrored in the derivation of the word from the Latin sal. Although the book is clearly written for the layperson, these opening chapters are instructive and entertaining for all readers. Of several anecdotes that linger in my mind, I like the King Lear-like saga of the youngest daughter banished for likening her filial love to salt -- until she persuaded the friendly cook to serve up a low-salt dinner to the salacious father. (The authors' suggested derivation of the word salacious from sal is, however, suspect: the Latin salire, to jump, is the likelier root of a word that means something akin to frisky.) There is a good section on salt taxes and salt in the smuggling trade. We are asked to sympathize with the citizens of the Breton region in France who suffered unduly under the gabelle, a prerevolutionary salt tax, but do the authors miss a trick here? In the book's crusade against the iniquities of modern-day salt barons in the food industry, the obvious suggestion that salt should again be taxed, alongside tobacco and alcohol, is never made.

The chapters dealing with the more biologic topics of blood pressure and the kidney will not challenge the readers of the Journal. When it comes to the role of salt in hypertension, the agenda becomes clearer. The authors know that the best form of protagonism is a show of evenhandedness -- less skillfully done here, it must be said, than in the balanced pro-salt piece in Science last year (G. Taubes. "The Political History of Salt." Science 1998;281:898-907). A priori arguments are not a substitute for scientific experimentation. The results of current outcome trials of antihypertensive agents in which 200,000 patients worldwide are currently participating will establish the benefits and risks of such treatments. Extrapolations from the observations in populations with various levels of salt intake that reducing the average salt intake by 3 g per day will prevent 40,000 strokes in the United Kingdom may be right; they may also be wrong. The results of the Dietary Approaches to Stop Hypertension (DASH) study suggested that the focus on salt may have diverted attention from other interesting dietary interactions with blood pressure (L.J. Appel, et al. "A Clinical Trial of the Effects of Dietary Patterns of Blood Pressure." N Engl J Med 1997;336:1117-24). Readers of this book could be forgiven if they failed to appreciate our current ignorance about the cause of hypertension in 90 percent of patients.

An interesting point of debate is whether the importance of salt-dependent abnormalities in the few monogenic syndromes of hypertension that have been unravelled argues for a predominant role of salt outside these syndromes. Because all of these disorders involve directly, or indirectly, an increase of sodium and potassium exchange in the distal tubule, patients with these syndromes present with hypokalemia as a recognizable phenotype. It would be an implausible coincidence if all monogenic syndromes of hypertension turned out to have a phenotype that trips off the Auto Analyzer.

The book's historical perspective permits a nicely presented account of the speculation that blacks with hypertension in the Americas have been selected for salt-retaining genetic alleles as a consequence of the horrific conditions of the slave trade: not only the trans-Atlantic voyage but also the equally brutal conditions of imprisonment while awaiting transport. The award for best picture in the book goes to the copper engraving from the Bibliotheque Nationale of a slave trader licking a slave's face to assess his fitness for voyage (salty sweat was presumably bad).

In the final chapter ("The Industrial Conspiracy") the authors reach the climax of their mission to enlighten the unwary about the evils of salt. Perhaps the purpose of the early emphasis in the book on the social impact of salt in medieval times was to prepare us for an ending fit for a morality tale. If this is an unconscious irony, even more ironic is the authors' incredulity that the food and salt industry should seek to protect their interests, given the authors' own detailed examination and description of the economic importance of salt in history.

The book is an excellent and enjoyable read. The amateur who is satisfied with certainty will derive more from it than the impartial professional seeking a challenge. For the majority of doctors and specialists in hypertension who are prepared to accept that salt has a role in determining blood pressure, perhaps early in life, the book succeeds as an example of the precept, "First, do no harm." The argument is also strong that in an age of spiraling drug costs we must strive to pursue nonpharmacologic methods of treating and preventing hypertension. Even the lobbyists, however, will wish to read this tract with a grain of salt.

Reviewed by Morris J. Brown, M.D.
Copyright © 1999 Massachusetts Medical Society. All rights reserved. The New England Journal of Medicine is a registered trademark of the MMS.

Review

' ... one of the most informative and entertaining books that I have read. MacGregor and De Wardener have spent much of their scientific lives pursuing the association between salt and hypertension. They not only have a deep insight, but are able to convey their knowledge convincingly.' Marcus Müller, BMJ

'On the one hand this is a book with profound implications for public health, and on the other it is an entertaining and instructive account of a part of our diet that is too easily taken for granted, and ignored at our peril.' International Journal of Epidemiology

'The book contains an abundance of little known facts. It will hold the interest of the subspecialist, yet it is written simply enough to attract those outside medicine. Salt, Diet and Health is worthwhile reading for all.' Nadine Bazilinksi, MD, , JAMA

See all Editorial Reviews

Product Details

• Hardcover: 245 pages
• Publisher: Cambridge University Press (September 28, 1998)
• Language: English
• ISBN-10: 0521583527
• ISBN-13: 978-0521583527
• Product Dimensions: 9.2 x 6.2 x 0.7 inches
• Shipping Weight: 1.1 pounds
• Average Customer Review: 3.7 out of 5 stars  See all reviews (3 customer reviews)
• Amazon Best Sellers Rank: #5,122,065 in Books (See Top 100 in Books)

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Most Helpful Customer Reviews

4 of 4 people found the following review helpful:

4.0 out of 5 stars It'll change the way you eat, June 24, 1999

By 

R Greenlees ([e-mail]) (London, UK) - See all my reviews

This review is from: Salt, Diet and Health (Paperback)

Prior to reading this book, I considered myself to be quite partial to salt in meals; a regular dispenser of the white crystals from the receptacle on the table. I approached the subject as a skeptic, believing that our bodies cause us to partake of the right amount of salt to suit our needs.

After reading it, my behaviour changed markedly, and I find (as the book suggests will happen) that my "need" for salt has diminished.

The authors' argument proceeds as follows:

- Humans used to eat much less salt than they do now, and it is possible to prove a relationship between our larger intake today and the much higher rates of high blood pressure and concomitant diseases. Even today, in less advanced cultures where salt intake is less than 3g per day, high blood pressure is virtually unknown.

- High blood pressure is a central cause of heart attacks and strokes.

- Our physiological requirement is for only a small quantity of salt; the rest is "addiction".

- If you have high blood pressure, reducing your intake of salt modestly to 5g per day can have the effect of reducing your blood pressure. (Tips for measuring your daily intake are given)

- Excessive salt intake can also be linked with: fluid retention in women; certain forms of kidney disease; osteoporosis; kidney stones; carcinoma of the stomach; and asthma.

- A link between high blood pressure and salt intake is not a new idea. However, vested interests have conspired (with commercial food interests acting in much the same way as tobacco interests have done) to obstruct attempts to use this to encourage a reduction in salt intake.

Various peripheral subjects are explored in the book. For example, it deals extensively and humorously with the very central role salt has played in society in the past: a source of wealth and tax revenue, a symbol of wit, durability, friendship and virility. The book covers the history of salt extraction, and the evolution of now firmly established links between high blood pressure and heart disease and other associated conditions.

The thesis appears to be rigorously argued (though as a medical layman I cannot be the judge of that). Since it was published, the level of publicity about the dangers of salt appears to have increased, with some purveyors of processed foods committing to reduce the salt contents of their wares. For this reason, I would suggest that the book has stimulated debate on the subject; and that must be a good thing. If the links are as direct as is here suggested this may have prolonged some lives already.

Despite the fact that a wide view is taken of the subject of salt here: history, significance, health implications; this book is not all light reading. It is clearly not intended to be an academic paper for publication in a peer-review journal. However there are some parts which may seem heavy reading and somewhat difficult to understand at the first encounter for medical neophytes like me.

In summary: a powerful thesis, an interesting discussion of the subject, don't take it to the beach with you.

1 of 1 people found the following review helpful:

2.0 out of 5 stars Good but contains errors and not sufficiently comprehensive, June 7, 2005

By 

greenwillow "wildeaboutsteroids" (England) - See all my reviews

This review is from: Salt, Diet and Health (Paperback)

Professor MacGregor is to be applauded for his efforts at informing the public about the hidden salt in foods, especially in convenience foods, and for seeking to bring about a reduction in the levels of salt added to food by manufacturers. He and his co-author have enlarged on these matters and other aspects of salt in this book. Unfortunately two glaring errors render the book less than helpful to those most in danger of or most harmed by salt. No mention is made of obese steroid victims, whose weight gain is caused by sodium and water retention, and who would lose much of their excess weight by curtailing their salt intake. And the book states categorically that HRT does not cause these problems, whereas it is, sadly, many women's experience that HRT does indeed cause severe water retention and weight gain. Like the steroidees, obese HRT victims would also lose excess water/weight by curtailing salt intake. Let us hope that if a revised edition is produced these errors will be corrected and that it will also advise that patients taking steroids or HRT should be warned not to eat salt or foods containing salt while taking their medication.

1 of 1 people found the following review helpful:

5.0 out of 5 stars A Wonderful Important Book, January 13, 2003

By A Customer

This review is from: Salt, Diet and Health (Paperback)

Excuse the cliche, but everyone should read this book. After an interesting historical overview on human consumption of salt, the authors present a clear and compelling argument about the strong link between salt/sodium consumption and disease. I recommend that people interested in this should also read "The Salt Solution", which is perhaps a more accessible, shorter, and simpler book with a similar message. This book is an excellent companion to "The Salt Solution" because it lays out, in a more traditional academic style, the evidence from medical research studies published in reputable journals, the indisputable harmful effects of salt/sodium.

This is the book that you (or anyone skeptical of the salt/disease connection) would want to have if you were not satisfied with the credibility of typical trade books and, instead, wanted to see data, graphs, and careful arguments based on primary source research articles.

Also fascinating is the section on the salt industry and food processing industry response to efforts to educate the public about the dangers of salt consumption. These responses are eerily similar to those the tobacco industry ... perhaps not a surprise, given that many tobacco and food processing companies are owned by the same corporation and presumably employ the same lawyers and public relations teams. Read this book and you will realize that salt/sodium is bad stuff that is hidden in large quantities in many common foods. It could save you from early onset of heart disease, stroke, stomach cancer, osteoporosis, and other maladies that you can have some control over if you decide to become more salt-sodium aware. This book is a good start to doing that.