I was thinking about the astonishing resilience of the cholesterol hypothesis the other day – something I often do. As you may know the ‘authorities’ in the US have now decreed that cholesterol in the diet is no longer a dietary factor of concern, as it has no effect on cholesterol levels in the blood.
Well my, my, this was discovered sixty years ago by Ancel Keys. However, several decades later various US Departments seem to have noticed this astonishing fact. They have sprung into immediate action and proposed that cholesterol is removed from the guidelines – as a dietary substance to be avoided (well it hasn’t quite happened yet, but it will).
No doubt they will take about two hundred pages of verbose guff to state this, along with all the reasons why no-one was actually wrong, and no-one ever really said that cholesterol in the diet should be avoided in the first place blah blah de blah. I certainly would not expect that the words ‘we were wrong’ will be found anywhere in the document, at least not in that order.
Blimey though, sixty years to get rid of a recommendation with never a scrap of evidence to support it. Not a single scrap. Of course, cholesterol in the blood is still bad. At least bad cholesterol is still bad, whereas good cholesterol is still good. Even though neither thing is actually cholesterol at all. But why let science get in the way of a good scientific hypothesis.
Hydra, or blob.
I was thinking should I call this blog, the ‘hydra’ or the ‘blob’. Because, when it comes do the cholesterol/diet-heart, or the ‘whatever you now want to call it, because you can call it almost anything you like hypothesis’ we see both mechanisms, multiplication and growth/mutation.
From the hydra perspective, if you cut off the head, this hypothesis simply grows a couple more. We now know it is not cholesterol in the diet that is bad. But anyway that doesn’t matter, for another head grew years ago. It is the ‘saturated fat is bad head’. If you attack that, it is the ratio of saturated to polyunsaturated head that suddenly appears. And if you attack that, the monounsaturated head appears, or the odd-chain saturated fat head, or even chain, or short chain. Chop chop, more heads.
In the blood, it is not LDL ‘bad’ cholesterol that is the problem, it is the new head of the ratio of good to bad cholesterol. Or is it dyslipidaemia, or it is oxidised cholesterol, or particle numbers, or small dense ‘bad’ cholesterol, or light fluffy ‘good (and simultaneously) bad’ cholesterol. Chop, chop. OMG not more bloody heads.
However, there are also good reasons for calling the many headed cholesterol hypothesis the blob, as it just grows and grows bigger. Attack it with contradictory evidence and is also capable of engulfing it, using your evidence to grow bigger and stronger. ‘Run for your lives.’
The French have a high cholesterol diet, a high cholesterol level in the blood, and low rates of heart disease. ‘Ah yes, that it because they eat lightly cooked vegetables, eat lots of garlic and drink red wine.’ The blob, gentle readers shrugged, grew a few pseudopods and engulfed these contradictions, digesting them with a contented sigh.
Eventually the hypothesis became ‘multifactorial’ a state in which any attack on any part of it is doomed to fail amongst a forest of heads attached to a monstrous blancmange like organism. The cholesterol hypothesis has become so massive and shapeless that any attempt to attack it is doomed to failure. You will be simply turned to stone, or engulfed. It will be lot longer than another sixty years before this hypothesis will finally keel over and die – I fear.
After all, the fact that cholesterol in the diet has no effect on cholesterol levels in the blood has had not the slightest discernible effect on a hypothesis that began life as… the cholesterol hypothesis. Although I defy anyone to tell me what it has now become.