Saturated fat and coronary heart disease
Part 3: Supportive studies?
There have been a handful of studies which do seem to support the lipid hypothesis. It is these that are quoted to support the statement that "a saturated fat diet is a risk factor for CHD". But these studies, as well as being the minority, are not always what they seem.
For example, a quoted Finnish study, published in 1985, was hailed as a great success because "The program markedly improved the risk factor status".
This was a 5-year study involving 1,222 men.[1] During the study period, the intervention group were advised and monitored on diet, smoking, exercise, etc. If they had high blood pressure or high cholesterol it was treated with drugs. The control group carried on eating a fatty meat diet.
By the end of the study period the "predicted risks for CHD were halved" in the intervention group.
Note that this applied only to the "predicted risks", not to the numbers of heart attacks. All the study really showed was that the men in the study would do as they were told.
This study was unusual as it had a 10-year follow up.[2] During this time, the intervention group were still seen regularly and advised and treated. At the end of this period, the results were as follows:
|
Intervention
|
Controls
|
|
| Total deaths |
67
|
46
|
| Cardiac deaths |
34
|
14
|
Not only do these figures show that those who continued to follow the carefully controlled, cholesterol lowering diet had more deaths in total, they were more than twice as likely to die of heart disease as those who didn't — some success!
Dr Michael Oliver, Professor of Cardiology at Edinburgh University's Cardiovascular Research Unit, commenting on these results in the British Medical Journal, wrote that:
'This runs counter to the recommendations of many national and international advisory bodies which must now take the recent findings from Finland into consideration. Not to do so may be ethically unacceptable . . . We must now face the fact that the evidence from large, well conducted trials gives little support to hopes that altering the lifestyle of the community at large, when started in middle age, will reduce cardiac deaths or total mortality.' [3]
References
1. Miettinen TA, et al. Multifactorial primary prevention of cardiovascular diseases in middle-aged men. JAMA 1985; 254: 2097-2102.2. Strandberg TE, et al. Long term mortality after 5-year multifactorial primary prevention of cardiovascular diseases in middle-aged men. JAMA 1991; 266: 1225-9.
Oliver MF. Doubts about preventing coronary heart disease. BMJ 1992; 304: 393-4.
