22 November 2017

Face the fats: what’s the science for dietary guidelines?

Clinical Nutrition

Where is a wonderful saying by Mark Twain; “It ain’t what you don’t know that gets you into trouble. It’s what you know for sure that just ain’t so”.  Today, books by Twain no doubt carry trigger warnings lest some university student gets upset by an idea they don’t like.

Unfortunately, there are some in medicine who also need trigger warnings and are not interested in hearing views contrary to their own. When British consultant Clive Bates visited to talk about tobacco harm reduction (including to a parliamentary committee) various health bodies refused to meet with him. Why? Because he supports vaping for harm reduction and they do not.

You would think it makes more sense scientifically to hear the arguments of those with a different view in emerging areas (before anyone raises anti-vaxxers, vaccines are not an emerging area).

So, the rest of this article carries a trigger warning. If you don’t like your ideas on dietary guidelines and saturated fats to be challenged, then turn the page or otherwise look away now.

There is a startling graph on page 328 of Big Fat Surprise, by Nina Teicholz, which shows the percentage of obese people in the United States between 1971 and 2006. There is an inflection point where the graph changes from a flat line to an incline. This inflection point is the first introduction of low fat dietary guidelines in that nation.

One of the arguments put by those in public health for the increase in rates of obesity (and type 2 diabetes) is that the public do not follow the guidelines. Sales figures for vegetables, red meat, grain products, vegetable oils and full fat dairy show the exact opposite. The public has adopted a low saturated fat diet over the last 40 years – to its detriment.

There has been a growing view that this advice was not based on science.

A 2014 paper in JAMA stated “Reducing total fat (replacing total fat with overall carbohydrates) does not lower cardiovascular disease risk …”

In 2015 the BMJ published something even more damning: “Dietary recommendations were introduced for 220 million US and 56 million citizens in the UK in 1983, in the absence of supporting evidence from randomised control trials.”

American congressman and physician, Andy Harris MD wrote on The Hill; “… the lack of sound science has led to a number of dietary tenets that are not just mistaken, but even harmful – as a number of recent studies suggest”.

A confluence of many coinciding historical events got us to this point.

Simplified, our views on saturated fats and cholesterol have been shaped by the “settled science” promoted by American physiologist, Ancel Keyes, in the 1960s. His ability to shout down critics rather than his scientific method (based on selecting six of 22 countries) won the day.

Now, the Prospective Urban Rural Epidemiological (PURE) study of 135,000 people in 18 countries over seven years has changed the “game”. It found a high-carbohydrate, low-fat diet was associated with increased mortality and heart disease.

Total and saturated fats were associated with a decreased risk of death. Fat consumption was not associated with cardiovascular disease, stroke or mortality.

Furthermore, the study found eating fruits and vegetables beyond moderation did not have any health benefit.

It has turned conventional thinking upside down. To quote author Dr Mashid Dehghan (PhD) from Canada’s McMaster University: “Global dietary guidelines should be reconsidered in the light of these findings.”

What has been the response to this? Attempts to discredit the work while putting fingers in the ears and singing “la la la”.

The main Australian dietitians group, the Dietitians Association of Australia, continues to promote a diet high in grains (carbohydrate) and low in fat.  A glance at their website shows they receive sponsorship from manufacturers of grain-based foods.

Supporters of ketogenic, paleo and other low carbohydrate health fat (LCHF) diets are castigated for “cutting out whole food groups”. Vegetarian and vegan diets which cut out whole food groups do not attract this criticism.

You can speculate as to the reasons for this.

Ultimately, we have dietary guidelines, which were never based on rigorous science. Real-world outcomes show that the public, in following the guidelines, has become heavier and has higher rates of type 2 diabetes. Major research shows that the opposite of what we have believed is, in fact, the case.

We need to be scientists, not ideologues, and stop believing that which “just ain’t so”, despite believing it for 40 years.

Dr Joe Kosterich is a general practitioner based in Perth. You can read more at www.drjoetoday.com

References

1. https://jamanetwork.com/journals/jama/article-abstract/2338262 

2. http://openheart.bmj.com/content/2/1/e000196.full 

3. http://ajcn.nutrition.org/content/early/2010/01/13/ajcn.2009.27725.abstract 

4:doi: http://dx.doi.org/10.1016 s0140 – 673 (17) 32252-3

5. http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(17)32252-3/fulltext?elsca1=tlpr 

6. http://thehill.com/blogs/congress-blog/healthcare/353486-mandate-is-clear-flawed-dietary-guidelines-process-must-be 

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12 Comments on "Face the fats: what’s the science for dietary guidelines?"

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Susan Swanston
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Susan Swanston
6 months 28 days ago
I am not a scientist or expert, I am “just a GP” who happens to have an interest in weight management and I spend a significant proportion of my working life trying to help my patients lose weight, prevent type 2 diabetes or improve their diabetes control. I do not conduct RCTs but I do observe real people with real lives and real health problems. It is my observation that there are two distinct groups of people who suffer from obesity and type 2 DM. The first group are generally educated and the initial consult usually starts with the patient… Read more »
Kim Bland
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Kim Bland
6 months 30 days ago

Great article Joe and lots of good discussion. Clearly with this much difference in opinion if it’s one thing we can agree on it’s that we need to go back and look at this again. If it’s one thing we’re all trained to do it’s not to accept something because it’s always been that way. Keep searching, keep learning and always have an open mind to new ideas I say. Nice work Joe.

Jaclyn Montefiore
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Jaclyn Montefiore
7 months 15 hours ago
The repeated statement by policy makers and nutrition experts that Australians are not following the Australian Dietary Guidelines brings two questions to mind: 1) why have Dietary Guidelines at all if no-one is following them? Why waste millions of dollars of taxpayer dollars reviewing them at defined intervals if they are so ineffective at reducing the burden of chronic disease as has been proven over the past few decades? It makes no sense to continue with the same approach which has clearly failed and a change of course is urgently needed. Possibly something similar to the Brazilian dietary guidelines could… Read more »
Dr Rosemary Stanton
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Dr Rosemary Stanton
6 months 30 days ago
Jaclyn Those of us who worked on the Dietary guidelines would have loved to be able to do something as simple as the ones that the Brazilian government has brought out. Indeed I wrote an article for Australian Doctor on this very topic (published Sept 16, 2016). I would dearly love such guidelines and will continue to press for something similar. The NHMRC needs particular levels of evidence for all statements and guidelines and at this stage, although the Brazilian ones are so sensible, there is no published evidence on their efficacy. Hopefully such evidence will be forthcoming as WHO… Read more »
Brooke
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Brooke
7 months 17 hours ago
Thank you Joe, high time that the evidence is reviewed. As a GP I continually share in the frustration of my patients as they follow the Australian Dietary Guidelines, yes they are aware of them and as educated adults they follow them – usually as a dietician prescribed diet plan, yet they are growing larger, more depressed with aching joints. They walk or go the gym, but you just can’t exercise away a bad diet. The high amounts of grain based products and 2 serves of fruit a day leave them craving more carbs and they just can’t break the… Read more »
Malcolm Mackay
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Malcolm Mackay
7 months 1 day ago
Misinformation presented with such confidence. All the usual assertions are there. Discredit Ancel Keys – recent ‘white paper’ published which vindicates his findings. Claim the USA went low fat – national consumption data shows that fat intake increased with each decade. Cite the PURE study – yes, it did find poverty stricken groups living on refined carbs had higher death rates. Claim it’s unfair to wave the dietary guidelines at Paleo-Atkins diet but not plant-based diets – the reality is that vegetarian /vegan diets can meet all of the dietary guidelines. Who do we listen do? Joe Kosterich or authoritative… Read more »
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