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