This study is rather influential in the manner with which it has informed the current UK policy on statin prescriptions. Questions to the Department of Health (DoH) had revealed that the Framingham Study[1] is the gold standard for assessing the risk for Coronary Heart Disease. A response from the DoH had stated...
"There are a number of different risk assessment tools for coronary heart disease in use in England. Most of them derive from the Framingham prediction equations, which estimate CHD risk based on patients’ age, gender, blood pressure, total cholesterol, high-density cholesterol, presence of diabetes and smoking habit."
The reader would naturally assume that Framingham was a well considered study, that had helped to advance medical knowledge and made a significant contribution to knowledge of heart disease. The study first began in 1948 and it is still running today. It was conducted in Framingham, Massachusetts, USA and it initially included 5,209 men and women who all were between the ages of 30 and 62.
The chronological list of findings[2] first mentions cholesterol in 1961, with the words... "Cholesterol level, blood pressure, and electrocardiogram abnormalities found to increase the risk of heart disease". There are other research milestones and that will be addressed further on.
It is incorrect to state "electrocardiogram abnormalities found to increase risk of heart disease". The abnormalities discovered by measuring the electrical impulses from the heart muscle may denote an increased risk of a serious cardiac event. There is no possible way that the measurements taken can increase the risk of a serious cardiac event. The abnormality which is responsible for the amount of risk, is already pre-existing. This sloppy use of terminology can be very misleading.
The statement "blood pressure is found to increase the risk of heart disease" is also pure nonsense. Every human has a blood pressure. Humans must have to have some sort of blood pressure reading for the body to maintain life. It is useful to know which values or ranges are considered to be normal and one can then make accurate statements about the effect on the body, of any specific set of blood pressure readings.
The final piece of the 1961 statement of research milestones had implicated 'cholesterol level' in this triad of factors that supposedly had implications for increasing the risk of suffering with heart disease. In 1970, the director of the Framingham Heart Study made the following statements to The News; a newspaper for Framingham and Natick.
Page 36 The News, Framingham-Natick, Friday October 30th 1970
Findings of the Framingham Diet Study Clarified
Framingham - Although there is no discernible relationship between reported diet intake and serum cholesterol levels in the Framingham Diet study group, "it is incorrect to interpret this finding to mean that diet has no connection with blood cholesterol" Dr William B Kannel, director of the Framingham heart study has stated.
"It has been repeatedly demonstrated that blood cholesterol levels can be altered by changes in diet; and dietary alteration is still the most acceptable form of medical management for persons with elevated blood lipids" Dr. Kannel said.
"The available evidence indicates that coronary heart disease appears to result from a combination of contributing factors and that no single factor capable of producing the disease by itself has been convincingly demonstrated", he stated.
"However", he added, "if any common denominator does exist through which such multiple, inter-related factors operate to produce athersclerotic lesions, then some aberration of blood lipids is certainly the chief contender. It appears to be the thread running through the web of circumstances leading to coronary heart disease."
A number of blood lipids have been implicated in coronary disease, Dr. Kannel Said, but none more substantially than the blood cholesterol content. That blood cholesterol is somehow intimately related to coronary atherosclerosis is no longer subject to reasonable doubt because of massive evidence that:
- diseases associated with hypercholesterolemia are also associated with premature atherosclerosis.
- persons with inborn errors of cholesterol metabolism develop extremely precocious atherosclerotic disease
- persons with high cholesterol levels in epidemiological study populations have been observed to develop coronary heart disease with greater frequency than those with low cholesterol levels, the risk being proportional to the degree of elevation of the blood cholesterol.
- countries with high average cholesterol values among their citizens report high coronary death rates; those with low average cholesterol values report low coronary death rates.
- atherosclerotic deposits are usually loaded with cholesterol and the movement of cholesterol from the blood into the deposits has been amply demonstrated.
- producing high cholesterol values in animals produces atherosclerotic deposits that can be made to regress by lowering blood cholesterol.
"Moreover", Dr Kannel said, "the evidence incriminating diet in producing elevated serum cholesterol is quite substantial; for example,
- areas in which the population exhibits high cholesterol values characteristically have diets different from those where low values are characteristic.
- migrants from 'low cholesterol' areas to 'high cholesterol' areas are often subsequently found to have higher cholesterol levels and to have changed their dietary pattern.
- manipulation of diet can alter serum cholesterol values in a predictable fashion in humans and, in animals, can produce atherosclerotic deposits or cause established deposits to regress".
"The reason for the high cholesterol values frequently found in free-living population groups is not always apparent and the details of the mechanism involved, the role of inheritance, regulatory mechanisms, and what constitutes the 'normal range' of cholesterol values are not completely understood." Dr Kannel said.
A clipping of the actual newspaper cutting is here and in two excellent articles, written by Dr Michael Eades, in which the newspaper clipping is subject to a trenchant analysis, you can read how this supposedly significant study is less than accurate, here and here.
