by Dr John Briffa
This post reveals just how flexible a concept “evidence based medicine” is. When an official body wants to disparage or ignore a possible treatment it often says that it is early days or that the claim doesn’t have a good evidence base or that it hasn’t been tested for safety.
However, when an official body wants to promote a treatment produced by one of its sponsors that is known to cause serious side effects it is happy to gloss over them, saying blithely that scientists often disagreed and it all came down to a matter of judgement. It seems that what is important is not the evidence but who is making the judgement. [Editor]
Last month, I wrote a blog post about how there was no evidence that cholesterol-lowering ‘stanols’ and ‘sterols’ (found in some margarines and other ‘functional foods’) have benefits for health. In fact, the National Institute for Health and Care Excellence (NICE) whose job it is to assess the effectiveness of treatments, have explicitly stated: “People should not routinely be recommended to take plant sterols and stanols for the primary prevention of [cardiovascular disease].”
And yet, the British Heart Foundation (BHF) recommends their use. Why? I wondered if this might have something to do with the fact that one of its corporate partners is Flora pro.activ (a brand of sterol-enriched foods made by Unilever).
So on the 17th July, I emailed the BHF about this discrepancy. I asked how they could recommend sterols when NICE had clearly said that a randomised controlled trial lasting at least 2 years was needed test their effectiveness before advising people who are at high risk of experiencing a first CVD to take them. I also asked whether the BHF believes the fact that Flora pro-avtiv is a corporate partner of represents a financial conflict of interest?
On the 30th July, I got a reply from Professor Peter Weissberg, the medical director of the BHF. Here are the highlights from his email:
- They are not suggesting that plant sterols/stanols can prevent a heart attack
- They do help to reduce LDL cholesterol, which is a risk factor for heart disease
- Their information reflects this and has not been altered by their fundraising partnership with Flora pro.activ.
- The BHF has a very clear set of principles on the basis of which they work with commercial organisations.
- The amount of money they take from Flora pro.activ is a tiny percentage of their overall budget.
I emailed Professor Weissberg again, this time questioning the presumed benefit of LDL-cholesterol reduction and also to draw his attention, should he not be aware of it already, to the considerable body of evidence which suggests sterols have the potential for harm.
I pointed out that, as he had already accepted, sterols/stanols have never been demonstrated to have clinical benefit, “it appears that your support of them rests on their ability to reduce LDL-cholesterol levels (which you say is a risk factor for heart disease). Unfortunately, as I’m sure you’ll know, reduction of LDL-cholesterol most certainly does not assure clinical benefit. Ezetimibe – which has a similar mechanism of action to sterols/stanols – is a case in point.
“Also, if arsenic and cyanide were found to be effective LDL-cholesterol reducing agents, it still would not make sense to recommend them for people for the reduction of cardiovascular disease risk, right?
“The reason that I use this example is because, as you may know, there is a considerable body of evidence which suggests that sterols/stanols may have adverse effects on health. These are very well summarized in a paper published in the European Heart Journal in 2009 [Weingartner O et al. Controversial role of plant sterol esters in the management of hypercholesterolaemia. European Heart Journal 2009;30:404-409]. If you have not already read it, I urge you to.”
[Dr Briffa then goes on to produce a hugely impressive list of 17 or more papers detailing the risks of stanols which include an increased risk of cardiovascular disease in both sexes and in all age groups, damage to the lining of blood vessels, heart attacks, sudden cardiac death and a rise in the level of dangerous free radicals. For full details and references see the original post on his site.
“These findings were the reason for Health Canada, the federal department responsible for helping Canadians maintain and improve their health, to raise significant safety issues and not to allow functional foods enriched with plant sterol esters to be sold in Canada.
“I am sure you must be very busy but please take some time to consider this evidence. From what I can see from the research, we have no evidence at all that sterols/stanols improve clinical outcomes, and considerable evidence linking them with potential for harm. Until we have positive evidence regarding outcomes, wouldn’t the most prudent and safety-conscious thing be to not recommend sterols/stanols (as NICE does)?”
On the 6th August, Professor Weissberg replied:
“I am aware of a large number of publications, of varying quality and validity, on the subject of plant stanols and sterols and their potential benefits and harms. I would prefer not to enter into a debate on any one of them since they all have their strengths and weaknesses.
So, as with so much in science, interpretation of the data is not as straightforward as is sometimes presented. Nevertheless, we are agreed that, ideally, one would like to see appropriately designed outcome trials to test their role in protection against cardiovascular events. In the absence of such data (and I doubt they will ever be produced), it is a matter of judgement as to whether or not plant stanols should be included as part of a wider strategy to reduce cardiovascular risk, and different national bodies have come to different conclusions.
In drawing this correspondence to a close I would conclude by saying that the BHF only enters into partnerships after careful consideration of all the pros and cons of so doing. As discussed previously, the main objective of the partnership with Unilever is to utilise their considerable reach to help us highlight the risk of CVD to women.
I thank you for your interest in this project and assure you we take seriously all feedback we receive.
Notice here how Professor Weissberg makes no comment at all on the specifics of the studies, nor puts up one scrap of evidence to refute the concerns raised. And what are we to glean from his writing: “In drawing this correspondence to a close…” To me, that gives the impression Professor Weissberg wants to hear no more from me (or perhaps anyone else) on the matter. Case closed!
I think we deserve better, to be honest. I genuinely believe that, based on the evidence, there is a case to answer regarding the health effects of sterols, and it’s simply not good enough for Professor Weissberg to dismiss the evidence based on rhetoric to do with, supposedly, the evidence being of ‘varying quality and validity’. This is true of all science, so is Professor Weissberg suggesting we just go back to the dark ages and believe what suits us?
How many people do you imagine look to the BHF as being a reliable and credible organisation dedicated to our heart health? Lots, I would imagine. How do you think they would feel to know that when legitimate concerns are raised about products they recommend (some of which are made by a company the BHF partners with), their medical director just flatly refuses to engage with the science?
There is absolutely no evidence that sterols benefit health, but it seems the BHF is going to recommend them anyway, even in light of significant evidence suggesting they have the potential for harm.