For several years now academics and researchers who follow or research the low carb diet have been amazed and frustrated by the almost complete refusal of the low fat dietary establishment to acknowledge any studies showing their approach has serious flaws and is regularly found to be less effective than low carbs. (Previous posts on HiUK have set out the low carb case in some detail.)
It was this frustration that prompted the report put out yesterday by the National Obesity Forum summarizing the multiple criticisms and calling for an evidence based approach to public health. The predictable response has been to assert that the low fat advice is firmly evidence based. One expert said that the advice contained in the official Eatwell plate was based on ‘robust scientific approaches’ another warned that National Obesity Forum’s advice to eat more fat ‘could have adverse public health consequences’. There seems to be no inclination to have any kind of re-assessment.
This is why research by the medical journalist Jane Feinman, published here for the first time, is so important. She has found that around 50 high quality studies reporting strong evidence for the benefit of a low carb diet were absent from the list of trials considered by nutritional scientific committees in both the USA and the UK.
The only reason the low fat supporters can claim their advice is firmly evidence based is that the high fat alternative has never been properly looked a. So it could be that the majority of those repeating the evidence based claim for low fat, simply don’t know their subject.
Assuming it is confirmed that these trials are indeed missing – not something that is difficult to do – it would seem inconceivable that some reassessment won’t have to take place. On the other hand I’m tempted to say: Don’t hold your breath!
How appallingly the American nutrition establishment treated an expert whistleblower
By Jane Feinmann
In September 2015, the BMJ (British Medical Journal) published a paper by an American science journalist on an issue that has turned nutrition from a clinical backwater into what is probably the biggest medico-political controversy of the 21st century – a growing concern that official dietary guidelines to eat a low fat high carbohydrate diet have been influenced by the food industry and may be fueling an epidemic of obesity and type 2 diabetes.
The paper, ‘The scientific report guiding the US dietary guidelines: is it scientific? challenged the most authoritative source of this advice world-wide – the Dietary Guidelines for Americans (DGA), Written by Nina Teicholz, author of the 2014 bestseller, Big Fat Surprise (Scribe), the paper was a detailed analysis of the DGA’s latest 2015 update. It concluded that far from being firmly evidence based, the guidelines ‘fail to reflect much of therelevant scientific literature in its review of topics’.
‘In fact,’ she says, ‘there have been several large clinical trials, showing the benefits of saturated fats. These have been funded by public bodies such as the NIH (National Institutes of Health), conducted on tens of thousands of men and women in experiments and lasting up to 12 years. If you include this missing research, the overall conclusion would have to be that carbohydrate restriction may very well be the best hope in helping people combat the worsening metabolic state that leads to diabetes, obesity and heart disease.’
Crucial files missing from a government library
So how has the DGA got it so wrong? The problem, says Teicholz, is that the DGA relies for its evidence on the Nutrition Evidence Library (NEL), a little known but powerful institution, set up by the US Department of Agriculture in 1980 to provide all the nutrition evidence to support the DGA – yet which, for some unaccountable reason, is unable to carry a comprehensive collection of the relevant nutritional studies.
‘The DGA Committee’s 2015 update claimed that it couldn’t find any studies supporting the benefits of a low carb diet. The most likely reason is that there were none in the NEL,’ she says.
For Teicholz, the months since publication of the BMJ paper have been fraught. Two months after it appeared, the BMJ received a demand for its retraction – claiming the paper was a ‘distorted and error-laden campaign against the DGA’. It was signed by the Center for Science in the Public Interest (CSPI), a ‘consumer advocacy group’ based in Washington, and co-signed by 173 assorted clinicians from around the world.
A demand for retraction of a paper appearing in an academic journal is rare – and normally associated with serious scientific misconduct. So what were these multiple errors? So far the BMJ has acknowledged a single,relatively minor error. It has also initiated an outside review, a standard response to a demand for retraction, which so far has not come to a decision. ‘The CSPI demand doesn’t so much feel like an attempt to clarify and correct, more a move to silence debate about these issues,’ says Teicholz.
How nutritionists deal with an informed critic – denigration
Rather than making any effort to address her serious and carefully researched claims, the low fat establishment continued their attempts to sideline and denigrate her. Teicholz is an acknowledged dietary expert, yet in March of this year her invitation to speak at the National Food Policy Conference, a prestigious Washington DC food policy panel, was unceremoniously withdrawn. She was replaced by the President of the Alliance for Potato Research & Education. Someone who was unlikely to criticize the DGA.
Then In April, an article in the Guardian quoted nutritionist and Huffington Post columnist, Dr David Katz describing Teicholz as ‘shockingly unprofessional’ and – bizarrely – ‘an animal unlike anything I’ve ever seen before’. Those advocating low fat repeatedly claim their position is based on scientific evidence yet in response to a serious and detailed critique, evidence is abandoned and replaced with personal invective.
In February 2016, she had been invited to attend and offer testimony at a ‘listening session’ organised by the US Department of Agriculture, held to prepare for the forthcoming first-ever outside review of the DGA. It is to be done by the National Academy of Medicine, an independent, highly regarded scientific body set up US Congress.
Commercial interests helping to set policy
She was, she says, horrified by the sheer number of commercial organizations present and united in calling for a high carb low fat (HCLF) plant-based diet. They included the American Bakers’ Association, American Frozen Food Institute, Corn Refiners Association, Snack Food Association and the Plant-based Food Association, along with the Center for Science in the Public Interest, which had called for the retraction of her BMJ paper.
As Teicholz points out: nutrition, a science, is ‘plagued with vested interests and subject to the stranglehold of epidemiology’. So will yesterday’s report by the National Obesity Forum and the Public Health Collaboration,‘Eat Fat, Cut the Carbs and Avoid Snacking to Reverse Obesity and Type 2 Diabetes’, trigger a similar attack by vested interested in the UK?
Certainly the situation on this side of the Atlantic is remarkably similar. In March 2016 an updated version of the Eatwell guide was published – with an almost identical message to last year’s DGA – of continuing with a low fat high carb diet. It too has been admirably deconstructed by a leading nutritionist – Dr Zoe Harcombe -who also identified its sponsors.
What’s more, as I have discovered, the evidence base of trials which supposedly supports the Eatwell claims is also missing virtually all the high quality trials that support the low carb high fat position. Talk about cherry picking! The evidence it relies on is contained in in a report – Carbohydrates and Health - put out last year by a Department of Health body called the Scientific Advisory Committee on Nutrition SACN.
Official UK advice goes easy on sugar
At first sight it looks impressive with 65 pages of references. Yet among them is a large number of papers that strongly suggest commercial interests at work. There is no debate about whether sugar and carbs are good for the health, just a clarification about how much is too much. Sure it recommends halving sugar in diet – with five (five!) sugar cubes a day for children aged four to six and seven for those aged 11 and over.
But it insists that the current recommendation that carbohydrates should form 50 per cent of daily calorie intake should be maintained. ‘The total carbohydrate intakes at the current recommended levels show no association with the incidence of cardiovascular disease, type 2 diabetes or glycaemia’.
Committee fails to find trials that contradict its conclusions
SACN’s conclusion was that there was no need to change the advice on carbohydrate intake and there was a comment to the effect the committee had been unable to find good evidence for the benefit of reducing carbs.
Yet it took me little more than an hour to locate more than 50 authoritative well planned studies that found in favour of a low carb diet which had been published in leading journals and carried out with funding from Government or leading organizations. None of the following are to be found in the main body of the SACN report.
Take for instance the major study published in the prestigious New England Journal of Medicine in 2013 which is claimed by Dr Michael Mosley as ‘finally putting a huge nail in the low-fat coffin’ involved 7400 people, many diabetes, allocated randomly to a low fat or a high fat diet. The study was halted because after four years those on the high fat low carb diet were found to be 30 per cent less likely to have a heart attack or stroke and both men and women were half as likely to develop type 2 diabetes.
I think the whole list bears publication. Meanwhile here are a handful of papers that absolutely should have been included but were not..
Some missing trials showing benefits of low carb impact on heart disease and stroke
In 2014, a paper in the Annals of Internal Medicine by Bazzano LA et al reported the results of a randomised controlled trial, funded by the National Institutes of Health following 148 men and women eating either a low carb or a low fat diet – with the finding that the low carb diet was more effective for weight loss and cardiovascular risk factor reduction.
A similar finding was reported in a 2012 meta-analysis of 17 RCTs involving 1,141 patients, published in Obesity Review and a 2014 review of 72 major studies by Chowdhury R, published in the Annals of Internal Medicine. This study found that ’current evidence does not support cardiovascular guidelines that encourage high consumption of polyunsaturated fatty acids and low consumption of total saturated fats’.
Some missing trials showing benefit for type 2 diabetes and obesity
A major study published in the prestigious New England Journal of Medicine in 2013 was said by Dr Michael Mosley to ‘finally put a huge nail in the low-fat coffin.’ It involved 7400 people, many diabetes, allocated randomly to a low fat or a high fat diet. The study was halted because after four years those on the high fat low carb diet were found to be 30 per cent less likely to have a heart attack or stroke and both men and women were half as likely to develop type 2 diabetes.
In 2013, a paper in the American Journal of Clinical Nutrition, carried out at Peninsula College of Medicine UK, found that a low carb diet improves various markers of cardiovascular risk in people with diabetes.
A 2009 paper, published in the same journal, and funded by the National Heart Foundation of Australia is one of several reporting that a low carb diet offers ‘clinical benefits to obese people with insulin resistance’. And in 2015, Feinman RD provided evidence in the journal, Nutrition, supporting ‘the use of low carbohydrate diets as the first approach to treating type 2 diabetes’.
These examples are not taken from a body of minor research that can be safely ignored. This is authoritative well-conducted science – and it explains why an organisation like the National Obesity Forum has stepped into the political arena in the way it has. Now is the time to establish nutrition policy for the benefit of the Forum’s members and the general population.
http://healthinsightuk.org/
Graham
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