Sunday, July 24, 2011

Review of The Great Cholesterol Con by Dr Malcolm Kendrick (John Blake 270 pp)

A useful review by Dr. Alick Dowling, originally presented to the Bristol MedChi society in May ‘07

The Bristol MedChi Society’s programme this year featured “Doctors under Pressure”. Dr Kendrick’s book is relevant, because he is a maverick outsider, tilting at an established theory. “Doctors under Pressure” is also relevant to GPs, in thrall to a policy, imposed by the Department of Health’s setting targets: cholesterol levels to be measured and lowered by statins. It is the GPs and perhaps the advising cardiologists who will be blamed if it turns out that statins were not the best answer.

Readers of the book who start at the back – a surprising number do so – will be impressed by the final Postscript, moderate, full of common sense and in agreement with much of what the medical mainstream has been saying for years. Turn to the Introduction and readers will be faced with a critical view of the Diet-Heart/Cholesterol Hypothesis, presented with mordant humour not perhaps to everyone’s taste, but preferable to the paternalistic material that comes from the DoH.
An example:
“Frankly, the idea that an inanimate molecule can suck cholesterol out of a plaque is so laughable that I can’t begin to explain here how preposterous an idea it is. And moreover, I would challenge any scientist anywhere to explain exactly how it happens. A molecule that travels both ways through a concentration gradient? ‘Of course it does, now run away and play with your friends and leave the adults alone.’

When Dr Kendrick warns about unrecognised dangers of statins, his style changes.
“Taking a statin is now viewed, among doctors, as akin to taking a multivitamin or low-dose aspirin. If this book achieves nothing else but start a debate on this issue, then I will be perfectly content. Perhaps you think statins are harmless, so it doesn’t really matter all that much? Well if you are a foetus, statins are not harmless at all. But be afraid, be very afraid. In April 2004 an article appeared in the New England Journal of Medicine – ‘Central nervous system and limb anomalies in case reports of first trimester statin exposure. Though contraindicated in pregnancy they found 52 confirmed cases of birth defects, as high as anything found with thalidomide and with more serious defects. With statins now available over the counter in the UK there is an increasing danger that warnings about taking statins in pregnancy will go unheeded.”
How many of us know this? The current debate about side effects of statins since a recent article by Dr James Le Fanu is another reason to consider Dr Kendrick’s approach.

Sweeping it under the carpet is not an option when so many people have access to the Internet. His essay on the subject in Panic Nation (2005) demolishing the Great Cholesterol Myth has not been challenged, and now he develops the theme with detailed references starting with the emphasis that cholesterol is vital for our physiology. The case of cholesterol is controversial. Demonised as a cause of heart attacks, cholesterol is a vital component in our body, being a precursor of important enzymes. Its blood level is the cause of much anxiety, made worse by the assumption that its level in the bloodstream is related to the cholesterol in our diet.

Physiologists know this is not true. The cholesterol in our blood comes not from cholesterol in our diet but from what we each manufacture in our livers ourselves. Supporters of the Atkins Diet claim his high-fat diet does not raise cholesterol levels. This suggests natural levels are less susceptible to influence by diet or drugs than many believe.

Should we concern ourselves with the opinion of one doctor who has chosen to challenge the ‘consensus’ about the dangers of high cholesterol levels? Yes:

a) because the ‘consensus’ has often been wrong. Dr Kendrick gives examples:
“Another leech anybody, or perhaps a radical mastectomy, or a tonsillectomy, or a removal of toxic colon? What about that old chestnut ‘no bacteria can live in the human stomach? And ‘strict bed rest following a heart attack’ – how many millions did that kill?”

b) because Richard Feynman, Physicist said:
“Of all the many values of Science the greatest must be the freedom to doubt.”

The DoH, through public health campaigns, promotes false information demonising cholesterol as uniquely harmful. It is surprising that so many have accepted this view, including the absurdities of ‘good’ and ‘bad’ cholesterol. Edicts from the Department of Health pronouncing official policy, with targets set for GPs, do not inspire confidence. They come with the stamp of certitude, never a suggestion of possible error. The DoH discourages those who question its policies, yet certainties have recently been overturned, as in the case of the organism Helicobacter pylori causing peptic ulcer.

The U-turn regarding ‘Helicobacter pylori’ was not an isolated event. Previous reversals of treatment have been accepted by the DoH, usually ungraciously. We must follow Professor Feynman’s advice and we must doubt – even those of us with perhaps a natural reluctance to question advice from Government sources. We must also confront advice that conflicts with physiology or common sense, both of which apply to the edict that we should believe saturated fat and cholesterol intake affects blood levels.

Though dismissed by the establishment as a lone voice that can be ignored, there are many who support Dr Kendrick’s stance. Dr Richard Asher (1912-1969), a much admired medical educator wrote in 1968, when clofibrate was promoted to reduce cholesterol levels:
“Please do not write any more articles about cholesterol and coronary disease and the diet and drugs which are supposed to influence them. The facts about coronary disease are these: the less atheromatous your ancestors, the harder your tap water, and the more habitual exercise you take, the less likely you are to be troubled by it. Do stop bothering about whether your fats are saturated or unsaturated, help yourselves liberally to butter and stop propagating these erroneous legends.”
Richard Asher also said
“to name something by its supposed cause, whether or not that cause is the right one, is a very serious mistake. However sure of a cause clinicians may be, a diagnostic label must be descriptive and not causal.”
He deplored unconfirmed diagnoses being used, because this perpetuated error and delayed proper evaluation of the condition. A modern example is using the name: Diet-Heart cholesterol syndrome. Many years previously Asher had used cholesterol levels when assessing the dosage of thyroid for myxoedematous patients so he was familiar with their capricious levels. He never thought they had any relevance to heart disease.

The structure of Dr Kendrick’s book is impressive, though the list of Contents does not make this immediately clear – too many of the important sub-headings are buried in the text of the longer chapters. Chapter 1 is not contentious; a description of heart attacks follows mainstream thinking and research.

In Chapter 2 & 3 Dr Kendrick surveys cholesterol (‘good’ and ‘bad’), saturated fats and unsaturated, lipoproteins and triglycerides and disentangles the misnaming and complexities of these and much else.

Chapter 4, the shortest is about statins, prefaced by a quotation “One of the first duties of the physician is to educate the masses not to take medicine: Sir William Osler (1849-1919).

Chapter 5 describes the rise of the Cholesterol Hypothesis, and in Chapter 6 subtitled “Diet Has Nothing to do with Heart Disease” Dr Kendrick starts to dismantle the diet-heart hypothesis in 21 pages, finishing with a Postscript of favourite quotes.

Chapter 7 The longest: Though many researchers have given up on the idea of the diet part of the diet/heart hypothesis, Kendrick is more isolated in challenging the cholesterol part. He writes as a convert. He used to believe that raised cholesterol levels caused heart disease. However when he realized that raised cholesterol levels were not a risk factor for strokes he had to revise his opinions, and this chapter is the heart of the book. Some readers might find it hard going, but his enthusiasm and style make it worth persevering.

Chapter 8 is the last in this section, entitled Statins and Heart Disease, and involves Dr Kendrick in assessing the many studies that have been made on this controversial subject. He has learnt how to recognize the weasel words that conceal rather than reveal the truth. ‘Might indicate’ ‘could show’ etc. Statistical evidence is often hard to judge – most doctors have had no training in this and Kendrick’s advice is enlightening:
How to do Scientific Studies – for Five-Year-Olds.

Rule 1 If you have more than one uncontrolled variable in your study you can’t prove anything.

Rule 2 If you think you have proved something in a study with more than one uncontrolled variable, Rule 1 shall apply.

Chapters 9, 10 & 11 (63 pages) are in effect a 2nd book (two for the price of one!) and provide an alternative hypothesis for the question What Causes Heart Disease. Readers who are not particularly interested in the ins and outs of cholesterol might well start with this part of the book – perhaps having already read the postscript, but we should at least do Dr Kendrick the courtesy of reading his book when he has taken the trouble to provide so much supporting evidence for his contention.

There are of course criticisms to be made of such an ambitious venture. The number of acronyms can be bewildering– an alphabetical list of them could easily be provided and if these were indexed the lack of a general Index would be easier to bear. An expanded list of Contents would help readers who wanted to refer back or forward.

Most medical readers will learn something new from this wide enthusiastic survey of current treatment for heart disease.

Disclosure: I am grateful to Professor Stanley Feldman, Professor Vincent Marks and the 16 other contributors to the essays: “Unpicking the Myths we’re told about Food and Health” – the subtitle of Panic Nation published July 2005. Many subjects, including Dr Malcolm Kendrick’s essay The Great Cholesterol Myth, considered in Panic Nation provide scientific justification for assertions made earlier on common sense grounds in Enjoy Eating Less. It is a relief to find such a raft of expert opinion to sustain them.

Received direct from author

Seaweed 'is natural way to protect the heart' as algae helps bring down blood pressure

This is all theory. No clinical evidence is presented

It's hardly the most appetising vegetable side dish. But tucking into a clump of seaweed at dinner time could help stave off heart attacks, say researchers. They have discovered key ingredients in the plant that help lower blood pressure, similar to commonly prescribed drugs.

According to a major study, seaweed is a rich source of proteins known as bioactive peptides – which are also found in milk. These chemicals have a similar effect to ACE inhibitor drugs, which are widely prescribed to help lower blood pressure and prevent heart attacks and strokes.

Seaweed is rarely eaten in Britain but has been a staple of the Japanese diet for centuries. Popular varieties include Wakame, used in miso soup, Kombu, and Nori, which is dried and used to wrap sushi.

One of the few types eaten by Britons is the red seaweed called laver, which is used to make laver bread. But experts insist many of the clumps found on our beaches are, in fact, edible. Dr Maria Hayes, of the Teagasc Food Research Centre in Dublin, said seaweed - known as macroalgae - was an 'untapped source' of these healthy ingredients.

The research, published in the American Chemical Society's Journal of Agricultural and Food Chemistry, looked at evidence from 100 other studies. It called for more effort to exploit the bioactive compounds and 'their potential for use and delivery to consumers in food products'.

The report stated: 'The variety of macroalga species and the environments in which they are found and their ease of cultivation make macroalgae a relatively untapped source of new bioactive compounds, and more efforts are needed to fully exploit their potential for use and delivery to consumers in food products.'

Seaweed is very low in calories and some scientists claim it helps weight loss by preventing the absorption of fat. Japanese researchers recently found that rats fed a certain type of seaweed lost 10 per cent of their weight.


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