Dietary Paradoxes
If something contradicts the accepted wisdom it is called a paradox. In the field of diet and heart disease there are many 'paradoxes' — But do they actually add to other evidence and show that the accepted wisdom is what is wrong?
'Paradox' is a word that is increasingly used in the context of diet and heart disease. This is because there are populations who eat prodigious amounts of so-called 'unhealthy' foods such as animal fats, but have low levels of heart disease.
The French Paradox, first described in 1987,[1] is perhaps the best known. It concerns the observation that the French have high consumptions of meat and fat, yet have low rates of heart disease. This is thought to be down to their intakes of red wine and olive oil,[2] but this hypothesis doesn't explain the other paradoxes.
For example, there is an Alpine Paradox in Switzerland where a great deal of high-fat cheese is eaten, red wine is conspicuous by its absence and olives don't grow;[3] and a Greek Paradox, where meat consumption is also higher than average.[4]
The Spanish Paradox is a good example of how researchers simply could not understand that these 'paradoxes' are not paradoxes at all; they actually provide evidence that high-animal fat diets are the truly healthy way to eat. You will see what I mean when you read their findings and then their conclusions. This study noted that between 1964 and 1991 in Spain bread consumption fell by 55%, rice consumption fell by 35%, and potato consumption fell by 53%. Over the same period, there were also some spectacular increases: beef consumption rose by 96%, pork consumption went up by a huge 382%, 312% more poultry was eaten, and full-cream milk consumption rose by 73%.
The study noted that, during this period, heart disease deaths fell by 25% for men and by 34% in women; high blood pressure rates improved; and there were fewer stroke deaths.[5] Under the circumstances, you might expect that the authors would suggest that the dietary changes might have been responsible for the changes in patterns of heart disease. But paradoxically, they didn't. To say such a thing, when 'everyone knows' that fats and meat are bad for you, isn't politically correct. In their conclusions they state: 'Nevertheless, our results, in the context of current knowledge about the relation between diet and health, suggest several dietary recommendations that might be applied to the prevention of CVD in Spain: Promote moderate consumption of all meat (beef and pork in particular), increase consumption of foods rich in complex carbohydrates (bread, rice and so on) and encourage use of skim milk and low-fat cheese.'
In other words, they suggest that the Spanish should stop eating their protective and truly healthy diet, and change to our version of what is 'healthy'!
The Italian Paradox is not a dietary one, but is still another paradox as it runs counter to politically correct health advice. This concerns the observation that the Italians have very little cardiovascular disease — yet they are a nation of heavy smokers.[6-7]
Social deprivation is another 'risk factor' for heart disease. The Albanian paradox concerns the fact that, although Albanians have the highest level of social deprivation in Europe, they have a coronary mortality rate which is similar to that of Italy, and only half the United Kingdom rate.[8]
In fact all across the Mediterranean region, heart disease rates are low regardless of the supposed 'risk factors' in various regions.
The Northern Ireland Paradox concerns a population with a great deal of coronary heart disease, but which doesn't have high rates of the expected 'risk factors'. Belfast has a coronary artery disease death rate that is more than 4 times higher than in Toulouse, France, despite almost identical coronary 'risk factors'.[9-10]
On the other side of the coin are those countries which do eat so-called 'healthy' foods but have higher heart disease deaths. One such is the Swedish paradox where a reduction in saturated fat consumption was followed by an increase in heart disease.[11]
The Israeli paradox is similar — cardiovascular disease is high despite a high consumption of 'healthy' polyunsaturated vegetable oils.[12] Having one of the highest dietary polyunsaturated to saturated fat ratios in the world — Israel has a consumption of omega-6 polyunsaturated fatty acids 8% higher than the USA, and 10 to 12% higher than most European countries — Israeli Jews could be regarded as a population-based dietary experiment of the effect of the widely recommended polyunsaturated vegetable oil diet. However, despite such 'healthy' national habits, Israel has, paradoxically, a high prevalence of cardiovascular diseases, hypertension, Type-2 diabetes and obesity. There is also an increased cancer incidence and total mortality rate, especially in women, compared with western countries.
And then there is the Indian Paradox, an observation that a high prevalence of coronary artery disease in urban Indians is associated with low saturated fat intake.
In 1967 Dr S L Malhotra, Chief Medical Officer for the Western Railway system, reported that in Madras, in the south of India, the population was vegetarian, living mainly on rice.[13] The principal fat in their diet polyunsaturated peanut oil.
Malhotra compared the Madrassis with a population who lived in the north near Udaipur. Their religion allowed them to eat meat and their fat intake was almost entirely from animal sources and highly saturated. They cooked in ghee (clarified butter) and had what was probably the highest butterfat consumption in the world.
Present-day wisdom would predict that the vegetarians would have the lower rate of heart disease, but Malhotra found the opposite: the vegetarian Madrassis had 15 times the death rate from heart attacks compared to the northern Indians even though those in the north ate nine times as much fat — and that fat was animal fat. Twenty years later, a paper in the Lancet noted an increase in heart-attack deaths amongst the northern Indians.[14] By this time the northerners' diet had been made 'healthier' by replacing the traditional ghee in their diets with margarine and refined vegetable oils. This finding was confirmed by a third study conducted 10 years later when researchers found that a low saturated fat diet did not prevent heart disease in the citizens of the city of Moradabad in northern India.[15]
Another paradoxical pattern is seen in Japan. After World War II, and influenced by US eating patterns, the Japanese increased their consumption of meat and animal fats by a huge amount, and cardiovascular deaths fell.
And there is even an American paradox when researchers showed 'that a high-fat, high-saturated fat diet is associated with diminished coronary artery disease progression in women with the metabolic syndrome, a condition that is epidemic in the United States.'[15]
These examples are hard to reconcile with the current paradigm of the causes of heart disease until you realise that they are not really paradoxes at all. What they all really demonstrate is that it is our 'healthy' paradigm which is wrong.
References
1. Richard JL. Coronary risk factors. The French paradox. Arch Mal Coeur Vaiss 1987; 80 Spec No: 17-21.
2. Renauld S, DeLorgeril M. Wine, alcohol, platelets, and the French paradox for heart disease. Lancet 1992; 339:1523-6.
3. Hauswirth CB, Scheeder MR, Beer JH. High omega-3 Fatty Acid Content in Alpine Cheese: The Basis for an Alpine Paradox. Circulation 2004; 109: 103-107.
4. Ulbright TLV, Southgate DAT. Coronary heart disease: seven dietary factors. Lancet 1991; 338: 985-992.
5. Serra-Majem L, Ribas L, Tresserras R, et al. How could changes in diet explain changes in coronary heart disease mortality in Spain? The Spanish paradox. Am J Clin Nutr 1995; 61(6 Suppl): 1351S-1359S
6. Grimes DS, Hindle E, Dyer T. Respiratory infection and coronary heart disease: progression of a paradigm. QJM 2000; 93: 375-83.
7. Romagnoli E, Caravella P, Scarnecchia L, et al. Hypovitaminosis D in an Italian population of healthy subjects and hospitalized patients. Br J Nutr 1999; 81: 133-7.
8. Gjonca A, Bobak M. Albanian paradox, another example of protective effect of Mediterranean lifestyle? Lancet 1997; 350: 1815-7.
9. Evans AE, Ruidavets JB, McCrum EE, et al. Autres pays, autres coeurs? Dietary patterns, risk factors and ischaemic heart disease in Belfast and Toulouse. QJM 1995; 88: 469-77.
10. Yarnell JW. The PRIME study: classical risk factors do not explain the several-fold differences in risk of coronary heart disease between France and Northern Ireland. Prospective Epidemiological Study of Myocardial Infarction QJM 1998; 91: 667-76.
11. Marmot MG, et al. Changes in heart disease mortality in England and Wales and other countries. Hlth Trends 1981; 13: 33-42.
12. Yam D, Eliraz A, Berry EM. Diet and disease — the Israeli paradox: possible dangers of a high omega-6 polyunsaturated fatty acid diet. Isr J Med Sci 1996; 32: 1134-43.
13. Malhotra S L. Serum lipids, dietary factors and ischemic heart disease. Am J Clin Nutr 1967; 20: 462-75.
14. (No authors listed.) Ghee, cholesterol, and heart disease. Lancet 1987; 2: 1144-5.
15. Singh RB, Niaz MA, Ghosh S, et al. Low Fat Intake and Coronary Artery Disease in a Population with Higher Prevalence of Coronary Artery Disease: The Indian Paradox. J Am Coll Nutr 1998; 17: 342-50.
16. Knopp RH, Retzlaff BM. Saturated fat prevents coronary artery disease? An American paradox. Am J Clin Nutr 2004; 80: 1102-3.
