Book review
These are some snippets from Part 3 of The Eskimo Diet: How to Avoid Heart Attack by Dr. Reg Saynor and Dr. Franklin Ryan reviewed below: “These four key papers are what is known as review papers – detailed, impartial summaries of all the research done to date on an important subject, written by a very experienced expert at the forefront of that research.” “A comparison of the thickening of the great artery, the aorta, between the inhabitants of two Japanese villages showed that one group lived by fishing and had a high intake of fish in their diet, while the other was a farming village where they ate much less fish. The researchers found that the high fish eaters had significantly less hardening of the artery than the low fish eaters.” “If most of us have narrowed arteries, or atheroma – as we unfortunately do – is there any use in following the Eskimo Diet? The answer is most positively: Yes!” “Our red blood cells are very pliable, and loss of pliability is believed to be another important factor in heart attacks. Red cells need to be able to change their shape in order to pass down fine arteries – remember some arteries are as small as 1/16 inch. Our red blood cells are sometimes three times the diameter of the little blood vessels they have to squeeze through, but the body enables the cells to go on their way by making the membrane covering the red cell elastic and supple. In some people who are prone to heart attacks, particularly if they eat a lot of saturated fat, the pliability of their blood cells is reduced.”
THE ESKIMO DIET
HOW TO AVOID HEART ATTACK
Dr. REG SAYNOR & Dr. FRANK RYAN
EBURY PRESS, LONDON 1990
PART III
Chapter 5: The Scientific Evidence
• After Hugh Sinclair’s pioneering start with the Eskimos, you can imagine the skepticism of the medical world – a feeling that remains prevalent today. Skepticism can only be answered by hard scientific evidence.
• The two Danish scientists, Jorn Dyerberg and Hans Bang, who accompanied Hugh Sinclair on his journey to Greenland in 1976 took samples of Eskimo blood back with them to the hospital in Denmark where they worked.
• When they analysed the fats in this blood, what they found surprised them greatly. In addition to the low blood triglyceride and other changes in such important components as HDL-cholesterol, they discovered profound differences in the presence of those essential fatty acids EPA and DHA.
• Dyerberg and Bang found that these were plentiful in the blood and tissue of Eskimos, while they were hardly present at all in the blood of people who ate a Western diet – and the degree of difference was enormous. Of course, we now know that, if you don’t eat fish or take fish oil, the levels in your body will be zero.
• The $64,000 question must be quite obvious. What do these fatty acids do in our bodies? Do they play any important part in our internal chemistry? If they do, our chemistry would obviously be disturbed if they were missing.
The four key papers
• These papers are what is known as review papers – detailed, impartial summaries of all the research done to date on an important subject, written by a very experienced expert at the forefront of that research.
• Prophylaxis of Atherosclerosis with Marine Omega-3 Fatty Acids. A Comprehensive Strategy. Published in Annals of Internal Medicine, 1987, volume 107, pages 890-9.
• Cardio-vascular Effects of n-3 Fatty Acids. Published in New England Journal of Medicine, 1988, volume 318, pages 549-57.
• Fish and Coronary Artery Disease. Published in British Heart Journal, 1987, volume 57, pages 214-19.
• Clinical Applications of Fish Oils. Published in Journal of the American Medical Association, 1988, volume 260, pages 665-70.
• These four papers will be quoted from as appropriate in this chapter.
What happens to the fat levels in our blood when we eat fish or take fish oil?
• The triglyceride level falls dramatically.
• After a fatty meal this level normally shoots up, but after taking fish oil even the rise in blood levels after such a meal is dramatically reduced.
• A comparison of the thickening of the great artery, the aorta, between the inhabitants of two Japanese villages showed that one group lived by fishing and had a high intake of fish in their diet, while the other was a farming village where they ate much less fish. The researchers found that the high fish eaters had significantly less hardening of the artery than the low fish eaters.
What happens to the clotting tendency in our blood when we eat fish or take fish oil?
• If most of us have narrowed arteries, or atheroma – as we unfortunately do – is there any use in following the Eskimo Diet? The answer is most positively: Yes!
• Although we have narrowed arteries, the vast majority of us feel perfectly well and can get about, perform our jobs and enjoy life to the full. If we can prevent that clot forming or halt/even improve, the furring up process in the arteries, we would do ourselves a power of good.
Blood viscosity
• There are many more properties of fish oils that prevent clots. If the flow is thicker (increased viscosity), the blood is more liable to clot. Fish oil reduces viscosity so that the blood will flow more freely in all our arteries – yet another beneficial effect on a known risk factor for heart attacks.
Red blood cells
• Our red blood cells are very pliable, and loss of pliability is believed to be another important factor in heart attacks.
• Red cells need to be able to change their shape in order to pass down fine arteries – remember some arteries are as small as 1/16 inch.
• Our red blood cells are sometimes three times the diameter of the little blood vessels they have to squeeze through, but the body enables the cells to go on their way by making the membrane covering the red cell elastic and supple.
• In some people who are prone to heart attacks, particularly if they eat a lot of saturated fat, the pliability of their blood cells is reduced.
A true case history
• Bob liked to come home to a good cooked dinner. He was especially fond of roast beef, Yorkshire pudding, roast potatoes (cooked in the juice – translate as saturated fats – of the meat) and all the trimmings.
• After a really good feed Bob would switch on the television, light his pipe and puff away contentedly.
• As he got older (he was now 52), he noticed a strange tingling sensation in his legs when he smoked his pipe in the evening.
• Tests at the local hospital showed that he had ‘peripheral vascular disease’, in other words that his arteries to his legs were furred up and narrowed.
• Bob noticed a marked improvement when he threw away his pipe.
• What happened to Bob? First, the high saturated fat content of his food had produced a high fat level in his blood, making the blood more viscous and sluggish and more prone to form clots.
• The smoking aggravated this condition, and at the same time stimulated chemical changes which caused spasm in the arteries of his legs.
• Add to this the fact that years of the same eating and smoking pattern had already furred up his arteries, restricting the blood supply to his legs.
• The reason he improved when he stopped smoking was that one of the danger factors had been eliminated.
• With the Eskimo Diet a lot more could have been achieved – and he could still have had his favorite meal, though without the Yorkshire pudding and probably less often!
What happens when we give fish or fish oil to real people with real medical problems?
High blood pressure (hypertension)
• In short-term trials fish oil has been shown to produce an improvement in people suffering from high blood pressure.
Brain development
• Professor Crawford, head of nutritional biochemistry at the Nuffield Institute of Comparative Medicine, has reported on the importance of fish in our diet for the development and nutrition of our brains. He gives his evidence for this in a book called The Driving Force, published in 1989.
Anti-inflammatory role
• Many properly conducted scientific studies worldwide have demonstrated the benefits of taking fish oil for arthritis, the skin complaint called psoriasis, and several other medical conditions.
Cancer
• There is a suggestion, though no conclusive scientific proof, that a diet high in saturated fat is linked to cancer of the breast and colon in humans, implying that a change of diet might reduce the risk.
Dietary fish in the prevention of heart attacks
• This is the most important of all the scientific evidence presented in this book. We shall look in a common-sense way at every known large-scale study that has examined the influence of eating fish on the rate of occurrence of heart attacks.
The Nelson study
• ‘Results from this study show that diets, including seafoods containing large amounts of Carbon 22 six double bond fatty acids, can be of considerable value in the treatment of patients with coronary problems.’
The Kromhout study
• The study was performed on 852 middle-aged men in the Dutch town of Zutphen, and was reported in the New England Journal of Medicine in 1985. Careful information about fish consumption in their diet was obtained from these men in 1960, when none of them had any symptoms or history of coronary disease. During 20 years of follow-up 78 of these men died from coronary disease.
• This study clearly showed that men who ate fish had a significantly lower risk of dying from a heart attack.
• ‘We conclude that the consumption of as little as one or two fish dishes per week may be of preventive value in relation to coronary heart disease.’
The Shekelle study
• These researchers agreed that eating fish was associated with a reduced death rate from coronary heart disease.
The Vollset study
The Curb study
Excitement and controversy
After the publication of Kromhout’s results, which confirmed Dr Nelson’s earlier report – and also given the intense background research which had gone on for almost a decade and pointed very strongly to an expected benefit from fish and fish oil – the US media and public were gripped by what might be termed ‘Omega-3 fever’. A number of books were published, some good and others making rather extravagant claims given that the research was still in its preliminary stages at this time. The American medical establishment began to worry, particularly at the possibility that the public might be tempted to take big doses of fish oil in the belief that what was good for you in small amounts was sure to be even better for you in large amounts. Senior figures in the medical establishment warned the public to wait and see. We believe they were absolutely correct. A number of very important aspects were as yet to be explored.
Playing devil’s advocate
• Almost all the scientific evidence given above appears strongly to favour fish or fish oil. But is there any evidence against fish oil?
• The safety aspects of fish oil will be discussed in detail at the end of Chapter 7. First, to test our hypothesis, we should answer three vital questions: Do the effects of fish oil in lowering blood fats wear off after several months of therapy? Does fish oil still retain its beneficial effect in the relatively small doses that we recommend for the general population? The third question, and one which lies at the heart of this book, can be put like this. Can we show that by eating more oily fish, or by adding fish oil as a supplement to our diet, we can reduce the risk of a heart attack?
• These three questions can only be answered by carefully evaluated scientific trial and assessment. Such trials have only just been brought to a conclusion, and we report on their findings in Chapter 6.
Chapter 6: The Heart Attack Revolution
Dr Reg Saynor’s seven-year study of the effects fish oil on heart patients
• Becoming interested in the properties of fish oil was a fateful decision for Dr Saynor: it altered the course of his academic career and involved him in more than a decade of intensive research
• Eventually this resulted in a large-scale study into the effects of fish oil on patients with raised blood fats, on patients with bad family health histories, and finally on the prevention of heart attack itself.
• Sinclair impressed him, not only because he had exposed himself to personal danger in journeying twice to one of the most inhospitable places in the world, but also because he had financed his expedition himself.
• It was with considerable difficulty that he persuaded some colleagues to try the effect of fish oil on their blood fats. He performed a small pilot study of fish oil’s effectiveness over the very short time of six weeks and felt vindicated at their astonishment on observing the improvement to their blood fat levels.
• The next step was to enlist the help and cooperation of a colleague, Dr David Verel, a consultant cardiologist at the Northern General Hospital, who agreed to refer patients to Dr Saynor for this treatment.
• Since that time Dr Verel ha been very helpful and co-author of many of the studies that Dr Saynor published.
Do the beneficial effects of fish oil wear off?
• At this stage we can answer the first of those questions posed at the end of Chapter 5. It is so essential to the theme of this book that we shall discuss it in some detail.
• One fact that is very certain from Dr Saynor’s study is that pure fish oil remains effective against raised blood pressure for as long as you are taking it.
• Dr Saynor’s findings have been confirmed in Japan, in Australia, and in the UK.
The effects of fish oil on cholesterol
• In Dr Saynor’s study the blood cholesterol level in his patients fell slowly but consistently, so that by the end of the first four years it was down 11%.
The effect of fish oil on fibrinogen
• Fibrinogen is the most important blood-clotting protein in our circulation. If too much of it is present, as in cigarette smokers, the blood clots more readily and this constitutes an increased risk factor for heart attacks.
Can it be shown that by deliberately increasing the amount of fish eaten, or by adding fish oil to the diet, the risk of a heart attack is reduced?
• Leaving Dr Saynor’s story again for a moment, let’s look at the most vital question of all from Chapter 5. The answer, quite categorically, is Yes.
• There is now evidence from three further studies that proves the case beyond any reasonable doubt.
The Burr study
• In the last week of September 1989 the UK media were excited by the publication of a very important study by Dr Michael Burr and his colleagues based in the Medical Research Council Epidemiology Unit, Cardiff, and West Wales Hospital, Carmarthen.
• Their study subjects were 2033 men under the age of 70, admitted to 21 different hospitals with a heart attack.
• Each man agreeing to take part in the study had his blood cholesterol measured at home, was weighed and was then randomly allocated either to have, or not to have, information on one of three special diets.
• Dr Burr’s conclusions were that only one group showed a major and significant fall in death rate from heart attack – those who ate a small amount of fatty fish per week or who took fish oil capsules.
• These patients had one-third fewer heart attacks than any other group which did not eat fish.