Sorry to get distracted from my series on what causes heart disease, yet again. However, I felt the need to blog about this article published in the BMJ on the 12th April 2016.
A group of researchers went back through the data from the Minnesota Coronary Experiment run between 1966 and 1973 in the US – on many thousands of participants. They were, in part stimulated to do this because they had previously looked at the Sydney Diet Heart Study 1966 – 73. In their own words:
‘Our recovery and 2013 publication of previously unpublished data from the Sydney Diet Heart Study (SDHS, 1966-73) belatedly showed that replacement of saturated fat with vegetable oil rich in linoleic acid (a polyunsaturated fat) significantly increased the risks of death from coronary heart disease and all causes, despite lowering serum cholesterol. Our recovery of unpublished documents and raw data from another diet-heart trial, the Minnesota Coronary Experiment, provided us with an opportunity to further evaluate this issue.’1
To make this clear. The Sydney Diet Heart Study (SDHS) was set up to show that replacing saturated fat with unsaturated fat would reduce the risk of heart disease The original researchers who set up and ran the SDHS did not fully publish their data at the time (one can only speculate as to why this may be so).
When this current group of researchers finally managed to get hold of the full data from the SHDS, it was found that replacing saturated fat with polyunsaturated fat did lower cholesterol, however:
REPLACEMENT OF SATURATED FAT SIGNIFICANTLY INCREASED THE RISK OF DEATH FROM CORONARY HEART DISEASE AND ALL CAUSES.
I am not normally a great fan of capitalisation, and using bold, but I think this statement needed that treatment.
Now, a few years later, the researchers who re-analysed the Sydney Diet Heart Study decided to try and find all the unpublished data from the Minnesota Coronary Experiment (MCE). (One can again only speculate as to why the original researchers did not reveal all of their data). The main points from this re-analysis were the following
- Though the MCE intervention lowered serum cholesterol, this did not translate to improved survival
- Paradoxically, MCE participants who had greater reductions in serum cholesterol had a higher, rather than lower, risk of death
- Results of a systematic review and meta-analysis of randomized controlled trials do not provide support for the traditional diet heart hypothesis
I shall paraphrase their findings:
THE MORE THE CHOLESTEROL WAS LOWERED THE GREATER THE RISK OF DEATH
The Minnesota Coronary Experiment (MCE), a randomized controlled trial conducted in 1968-73, was the largest (n=9570) and perhaps the most rigorously executed dietary trial of cholesterol lowering by replacement of saturated fat with vegetable oil rich in linoleic acid. The MCE is the only such randomized controlled trial to complete post-mortem assessment of coronary, aortic, and cerebrovascular atherosclerosis grade and infarct status and the only one to test the clinical effects of increasing linoleic acid in large prespecified subgroups of women and older adults.
Those who have read my ramblings over the years will not be in least surprised by this finding. Because, as you may know by now. I believe that raised cholesterol has nothing whatsoever to do with the heart disease. So, this finding is not a paradox to me. It is simply further confirmation of many, many, other studies which utterly contradict the cholesterol hypothesis.
I would not, however, hold my breath waiting for this study to make any difference to anything. My current favourite comment on this study comes from an opinion leader from the British Heart Foundation. It is, as follows:
‘Professor Jeremy Pearson of the British Heart Foundation commented: “This is an interesting study which shows that decreasing your intake of saturated fat can have a positive impact in helping lower cholesterol. More research and longer studies are needed to assess whether or not eating less saturated fat can reduce your risk of cardiovascular death.’
Read and weep gentle readers. Here is a man so completely and utterly convinced of the dangers of saturated fat consumption and raising blood cholesterol that he is incapable of grasping what this paper is saying. Max plank said that ‘Science advances one funeral at a time.’ There is at least one funeral, currently, that I can think would help to move science along.
Perhaps time from a quote from Professor John Ioannidis, who wrote a rather sad article recently, entitled Evidence-based medicine has been hijacked: a report to David Sackett.
‘This is a confession building on a conversation with David Sackett in 2004 when I shared with him some personal adventures in evidence-based medicine (EBM), the movement that he had spearheaded. The narrative is expanded with what ensued in the subsequent 12 years. EBM has become far more recognized and adopted in many places, but not everywhere, for example, it never acquired much influence in the USA. As EBM became more influential, it was also hijacked to serve agendas different from what it originally aimed for. Influential randomized trials are largely done by and for the benefit of the industry. Meta-analyses and guidelines have become a factory, mostly also serving vested interests. National and federal research funds are funnelled almost exclusively to research with little relevance to health outcomes. We have supported the growth of principal investigators who excel primarily as managers absorbing more money. Diagnosis and prognosis research and efforts to individualize treatment have fuelled recurrent spurious promises. Risk factor epidemiology has excelled in salami-sliced data-dredged articles with gift authorship and has become adept to dictating policy from spurious evidence. Under market pressure, clinical medicine has been transformed to finance-based medicine. In many places, medicine and health care are wasting societal resources and becoming a threat to human well-being. Science denialism and quacks are also flourishing and leading more people astray in their life choices, including health. EBM still remains an unmet goal, worthy to be attained….
“David, I was a failure when we started this conversation and I am an even bigger failure now, almost 12 years later. Despite my zealot efforts, my friends and colleagues have not lost their jobs. The GDP devoted to health care is increasing, spurious trials, and even more spurious meta-analyses are published at a geometrically increasing pace, conflicted guidelines are more influential than ever, spurious risk factors are alive and well, quacks have become even more obnoxious, and approximately 85% of biomedical research is wasted . I still enjoy science tremendously, focusing on ideas, rigorous methods, strong mathematics and statistics, working on my weird (and probably biased) writings alternating with even more desperate poetry, and learning from young, talented people. But I am also still fantasizing of some place where the practice of medicine can still be undeniably helpful to human beings and society at large. Does it have to be a very remote place in northern Canada close to the Arctic? Or in some isolated beautiful Greek island where corpses of unfortunate refugees are found on the beach or floating in the water almost every day, as I am writing this commentary, although no naval battle has been fought? Is there still a place for rational thinking and for evidence to help humans? Sadly, you cannot answer me any longer, but I hope that we should not have to escape to the most distant recesses of geography or imagination. Twenty-five years after its launch, EBM should still be possible to practice anywhere, somewhere—this remains a worthwhile goal.”2
David Sackett, the founder of Evidence Based Medicine, is now dead. I presume he is spinning in his grave at what has happened to medicine and medical research. Which is, currently, not based on any evidence at all. If the evidence does not fit with the currently dogma it is simply not published.
Does anyone in the higher reaches of the medical establishment actually give a stuff about this? It seems that they do not. Meanwhile the shelves of our supermarkets groan under the weight of the super-healthy polyunsaturated fat products that we are encouraged to eat, by the likes of the British Heart Foundation.
Yet, here is what the uncovered evidence from the largest study done in this area is screaming at us:
Greater cholesterol lowering, using polyunsaturated fats, increases the risk of death
So, British Heart Foundation, the question must be asked… are you killing people with your advice on saturated fat consumption? Perhaps you ought to think about changing it, before more people die.
Here is what the BHF currently say about saturated fats:
‘Swap these for unsaturated fats. Eating too much saturated fat increases the amount of cholesterol in your blood.’3
Do you have any actual evidence to base this advice on… any at all? If so, let’s see it. If not, change it.