Although small studies have been suggesting it for some time, the Grand Old Man of heart research has finally come out and said it, too: cholesterol cannot be looked on as the only cause of coronary disease.
The Seven Countries Study, set up in the 1950s to understand the causes of heart disease, has still to come up with a definitive answer to one of the greatest health concerns of the century.
But after studying the most recent data, gleaned over the past 25 years, it now believes the risk factors could be a complex mix of cholesterol, smoking, high blood pressure and diet.
The last factor, flagged by various heart disease studies in recent years, is suggested by the marked difference in levels of heart disease between the various countries and continents that make up the study. As has been noted many times before, Japan and the Mediterranean countries suffer far fewer heart problems than do people in the United States and the north European countries. Mortality rates in Japan and the Mediterranean countries ranged between 4 and 5 per cent, compared to 12 per cent in the United States and 15 per cent in northern Europe. These figures had already been adjusted for age, smoking, high blood pressure and cholesterol levels.
The one variation seems to be diet. The Mediterranean diet contains less meat, but more fish, fruits, vegetables and ethanol. The fatty acids consumed in north Europe and the United States were usually saturated, while those in the Mediterranean were monounsaturated. The antioxidant vitamins beta-carotene and A were also higher in the Mediterranean; flavonoid intake was twice as high in the Mediterranean as in the US and northern Europe, and highest in Japan.
The one other possibility is genetic differences between the continents, although that is harder to assess.
The study has thrown up many possible causes, but has finally laid to rest the idea that cholesterol alone is to blame (JAMA, July 12, 1995).