Most medical professionals strongly believe that cholesterol causes heart disease and that treating ‘raised’ cholesterol and bringing it down to a so-called ‘healthy’ level is beneficial for us all. However, I’ve been sceptical about both these ideas for many years now.
I’m not the only one, though, as quite a few individuals have expressed similar doubts about the ‘cholesterol hypothesis’. Because the cholesterol hypothesis is so firmly entrenched in so many people’s minds, and because dissenters are often from the fringes of (or outside) mainstream medicine, any scepticism is relatively easy to dismiss. I think. However, when someone from within the establishment expresses doubts, the impact can be that much greater.
And that’s why I was very interested to read an open letter expressing doubt about the wisdom of current cholesterol management strategies, co-authored by Harlan Krumholz, professor of medicine and cardiologist at the Yale University School of Medicine. The letter, which appeared in the journal Circulation [1], was written to the Adult Treatment Panel – a group of ‘experts’ charged with setting cholesterol guidelines for the American public.
The panel is due to issue new guidelines later this year, and the chances are it will recommend that we keep strong downward pressure on our cholesterol numbers. But not all individuals in the medical and scientific community agree with this approach, and one such dissenter is Professor Krumholz. In the letter, Professor Krumholz and his co-author highlight what I believe to be 3 very important points:
1. There is no scientific basis to support treating to LDL targets
Current recommendations are for people to lower their supposedly unhealthy LDL-cholesterol to a certain level. The problem is, no study has actually tested the benefits of this specific strategy. Professor Krumholz points out that there are many instances where cholesterol reduction has not translated into clinical benefits (e.g. reduced risk of heart disease or death). Actually, all the positive effects of cholesterol reduction appear to be limited to statins. The thing is, though, statins don’t just reduce cholesterol, they have other effects including an anti-inflammatory effect. What this means, in essence, is that the apparent benefits of statins may not be down to their impact on cholesterol, but other effects that have nothing to do with cholesterol.
He also points out that the benefits of statins do not appear to be very related to a person’s LDL levels before treatment. In other words, those with higher LDL do not benefit more than those with lower levels. This again points to the fact that statins probably do not work through cholesterol reduction. In the end, though, as Professor Krumholz points out, it does not matter whether LDL causes heart disease or not. What matters is that LDL levels are actually quite a poor predictor of someone’s risk, and therefore basing treatment decisions on LDL levels does not make sense.
2. The safety of treating to LDL targets has never been proven
So, we know that there’s no scientific basis to treating to a particular LDL level, but Professor Krumholz then goes on to point out that the safety of this practice is not established either. While there is quite a lot of evidence for the relative safety of statins, data in the long term is lacking, as is data on most other cholesterol-reducing agents. Some claim the very fact that cholesterol is being lowered should give us confidence that the benefits will outweigh any harm. However, as Professor Krumholz points out, we have instances where basing treatment decisions on ‘surrogate markers’ has led to harm. He cites examples of where aggressive treatment of diabetes and blood pressure has done more harm than good.
3. Tailored treatment is a simpler, safer, more effective, more evidence-based approach
Professor Krumholz makes the point here that current treatment strategies are inefficient, and that treatment decisions should not be made on the basis of cholesterol levels, but a person’s overall risk of cardiovascular disease. This more holistic approach, by the way, will likely see many people suddenly not ‘needing’ statins or other cholesterol treatments after all, like practically every one of the relatively young, fit, healthy, non-smoking men or women who have turned up a ‘raised’ cholesterol on blood testing.
I don’t expect Professor Krumholz’s views to go down a storm with the medical community and certainly not the drug companies. But I think he should be applauded for standing up and telling what he believes is the truth, even if this flies in the face of conventional ‘wisdom’.
References:
1. Hayward RA, Krumholz HM. Three reasons to abandon low-density lipoprotein targets: an open letter to the Adult Treatment Panel IV of the National Institutes of Health. Circ Cardiovasc Qual Outcomes. 2012 Jan;5(1):2-5.