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May 28, 2023 | Max Jenkinson
The Big Fat Lie: Seed Oils VS The Best Nutrition Studies Ever Made
We’ve been led to believe that the dietary guidelines and conventional wisdom about what’s truly healthy are infallible.
After all, isn’t science our beacon of truth?
With expert panels and consensus, we assume we’re on the right track. But my worldview was shattered when I discovered the shocking truth.
In the 1970s nutrition science was in its infancy.
Yet, in 1980, the first dietary guidelines were introduced in the US, and they’ve remained virtually unchanged ever since.
Is this because they just so happened to stumble upon the truth?
Or could it be that these powerful institutions are stubbornly clinging to their established stance, disregarding mounting evidence to maintain the status quo?
This graph points to the latter being true.
Today, we’re focusing on the saturated vs unsaturated fat debate.
Many doctors and scientist have done their due diligence and actually looked at the data.
They realized that our idea of saturated fat was completely wrong.
This was the cover of TIME magazine in June 2014.
But why did it take so long for this paradigm shift to occur?
The answer lies in data that remained hidden for over 50 years, only coming to light between 2013 and 2015.
Data from some of the most rigorous nutritional studies ever made.
Data from studies that could have reshaped the conversation in the late 70s and early 80s, had they been given the attention they deserved.
Before we explore these studies we need to understand how and why we got it so wrong.
Let’s start with how we rank the relative strength of the evidence from a study.
The Evidence Hierarchy
Within science, there is something called the evidence hierarchy.
It describes what kind of studies have the highest authority or the most trustworthy conclusions.
In other words, to what degree we should draw practical conclusions from them?
In order of evidence: (Greenhalgh’s evidence hierarchy)
Systematic reviews/meta-analyses of RCTs
RCTs (Randomised controlled trials)
Cohort studies
Case-control studies
Cross-sectional surveys
Case reports
Systematic reviews or meta-analyses use multiple RCTs to draw from when figuring out if a hypothesis is likely true or not.
RCTs are usually performed to determine the effectiveness of an intervention.
You have two groups, one being the control, often given a placebo, and the other group given the intervention.
Then come the observational studies, 3, 4, and 5 on the list.
Cohort studies look at groups of individuals with a shared experience over a specific period.
Case-control studies compare groups of people within similar circumstances.
The cases (people with the condition) compared to the control (people without the condition).
Cross-sectional surveys look at populations to derive a hypothesis of what is driving something (like a disease).
Case reports look at specific individuals.
The Unscientific Dietary Guidelines
Nina Teicholz, an investigative journalist, has written the book The Big Fat Surprise.
In the book, she brings up almost everything I’ve written about in this series.
She has also founded a non-profit organization, The Nutrition Coalition.
The goal is to establish a scientific foundation for the dietary guidelines and to make them transparent.
They have uncovered the unscientific process that led to the first dietary guidelines in 1980. And, also how they have been unscientific since.
The American dietary guidelines are updated every five years by an expert panel of 11-15 experts.
These experts have many conflicts of interest.
Brian Wansink, a famous scientist, sat on the panel as one of the foremost experts from 2007-2010.
After the unveiling of his unscientific process, he lost his position as a professor at Cornell and had many of his studies retracted.
Many of those studies laid the foundation for the dietary guidelines.
These studies, based on observation, were used even though they were low on the evidence hierarchy.
To give you a sense of how low the observational studies should rank:
Young & Karr found that 80-100% of observational studies can not be replicated in controlled experiments.
In 2010, in an attempt to make the process behind the dietary guidelines more rigorous, the Nutrition Evidence Library (NEL) was created.
In the 2015 guidelines, the NEL was used in less than 30% of the subjects covered.
They were not used in any of the controversial topics in nutrition.
Instead, they used studies from the AHA and the American College of Cardiology (ACC).
The same year Teicholz analysed the evidence for the three recommended diets.
The diets were, “U.S-Style, “Mediterranean”, and “Healthy Vegetarian”.
In this article written in the BMJ (British medical journal), she concludes the evidence is lacking for all three.
Just a short snippet about red meat.
You’ve probably heard red meat causes cancer. You probably couldn’t answer why you’ve heard this.
Well, it most likely stems from the WHO.
A team of experts spent two years looking at the data.
They reviewed 800 epidemiological studies and found 14 that looked at red meat and colon cancer.
13 of them showed no significant relationship.
The one that did showed only a slightly increased risk for colon cancer.
And this increase was only demonstrated in people that were overweight with a low legume intake.
Yet, this is not what you heard.
You heard that red meat causes cancer and probably thought this meant all cancers.
Are you starting to realise the issue of blindly trusting the “experts”?
How can we trust the studies?
That the expert panel that set our dietary guidelines lack transparency and evidence might not surprise you.
If we want to create evidence-based recommendations we need to first agree on what counts as good evidence.
Shouldn’t high-quality experimental studies generate evidence-based conclusions?
Evolution does not optimise for rational, objective, organisms.
Because of this, we have developed mechanisms such as logical fallacies, biases and dogma making it hard for us to see what is most likely true.
These human attributes have made it difficult for science to do its job, namely to figure out what is true.
Why Most Published Research Findings Are False written by Stanfords John Loannidis is an excellent article. It illuminates the difficulty science has to determine the truth.
Not only is the evidence they use often not scientific, but many experts are financially motivated to look the other way.
There are six experts on the “Birth-24 Month” subcommité, four of them are financed by companies that create baby formula.
Ancel Keys & The Best Nutritional Studies Ever
Most of the studies that are done on diet are epidemiological, meaning observational.
It is challenging to experimentally study diet in humans, especially over longer periods of time.
Because of this, these studies are few and far between.
Yet, luckily enough, Ancel Keys’s hypothesis gained massive publicity.
This led to his hypothesis being the most well-tested nutritional hypothesis of all time.
Lots of money was given to try to prove his hypothesis, creating some of the best nutritional studies ever conducted.
We shouldn’t draw conclusions from observational studies, this we can all agree on.
Maybe we shouldn’t even draw them from experimental studies because of the human factor.
If we can’t draw correct conclusions directly from studies, we need something else.
We need a logical framework to put the studies into. A logical framework beyond the studies.
Back to the zoo analogy (I do love it).
Animals in the zoo developed our diseases, what did we do?
We looked at their natural environment, and diet. Then we mimicked that, and the diseases reversed.
The evolutionary assumption: animals living in their natural environment do not develop disease.
Let’s look at nutritional studies through this assumption.
If the conclusion from them is not in line with our evolution, either our idea of our past is wrong, or the conclusion is.
Most often it is the conclusion.
The zoo you and I live in today is so far removed from the environment we evolved in.
It is a wonder that we are able to survive and sometimes even thrive.
That evolutionary mismatches lead to disease is an exceptional assumption to stand on.
This is why I want you to study our evolution and then correct our biggest mismatches.
This way you’d be much healthier than if you tried to follow the health science.
But, then again, I think we should do both.
We have two major dietary mismatches, lack of protein and overconsumption of seed oils.
Seed oils are:
Something we’ve never consumed
In a fatty acid profile we’ve never consumed
In an amount we’ve never consumed
This should be enough.
But, we are in the age of science, and we want evidence, whatever that means, to justify healthy choices.
If seed oils are our largest dietary mistake then the science should be clear.
But, as we now know science has its problems with objectivity.
Most studies are wrong.
Most studies are biased.
All conclusions are made by humans.
Despite this, there are some good studies out there.
The Forgotten Studies
In 2013, scientist Christopher Ramsden and his team recovered data previously hidden from an excellent RCT testing Key’s hypothesis called The Sydney Diet Heart Study.
They found that the replacement of saturated fat with seed oils significantly increased the risk of death from coronary heart disease and all causes.
Not the opposite as hypothesised by Keys.
They knew that there had been other studies made to test Key’s hypothesis.
In 1968, another RCT to test Key’s hypothesis started.
The study, led by principal investigator Ivan Frantz and co-principal investigator Ancel Keys, used the patients of one elderly home and six mental institutions as study participants.
Over the next five years, 9570 men and women between the ages of 20-97 were studied.
Because they were all institutionalised the scientist could control everything they ate.
They all ate the exact same meals with one difference, the fat the food was cooked with.
Two randomised groups, two variables, saturated fat and polyunsaturated fat.
During the study, they measured cholesterol, deaths, and a complete postmortem assessment of coronary, aortic, and cerebrovascular atherosclerosis.
“To this day, it stands as one of the most rigorous diet trials ever conducted.”
After the study concluded in 1973, it took another 16 years before anything was published.
The entire study was not published, but a conclusion was.
“For the entire study population, no differences between the treatment and control groups were observed for cardiovascular events, cardiovascular deaths, or mortality.”
There were rumours that the raw data from one of the most rigorous diet studies ever made still existed.
In 2015, Ramsden hunted down Ivan Frantz’s son and asked if the rumours were true.
The rumours were true, the data was still in Frantz’s basement.
Frantz’s son gave all the raw data to Ramsden.
Under the lead of Ramsden, a bunch of scientists from the NIH (National Institute of Health) analysed the data with new eyes and tools.
In the group that ate seed oils, the cholesterol was lowered as expected.
However, in an interview, Ramsden tells us,
“The people who were over 65 who had been on the diet for more than a year… The more their cholesterol was lowered the higher the risk of an adverse outcome.”
They found an inverse correlation between cholesterol and mortality.
For every 30mg/dL lowering of cholesterol, there was a 22% increased risk of dying.
“There’s no good evidence that reducing saturated fat makes you live longer. The best clinical trials we have reached the opposite conclusions.”
From the episode The Basement Tapes in his podcast Revisionist History
There have been five of these excellent RCTs looking at Key’s hypothesis.
Yet, they might be the best nutritional studies ever conducted.
In 2016, Zamora et al. looked at all of them and did a meta-analysis.
A meta-analysis of the only RCTs that specifically tested the effect of replacing saturated fat with polyunsaturated fat.
“In our main meta-analyses, based on the five randomized controlled trials that provided LA-rich vegetable oil in place of saturated fat, we found no evidence for reductions in either coronary heart disease mortality or all-cause mortality.”
These studies are at the absolute top of the evidence hierarchy.
None of them support the hypothesis and many of them show the opposite.
Despite this, the dietary guidelines still recommend seed oils and tell us to limit saturated fat.
They ignore this data, they ignore the best RCTs.
Why?
Well, I am not entirely sure. But, if you want to find out more you can check out the Nutrition Coalition.
Eating seed oils is evolutionarily illogical, chemically illogical, and scientifically illogical.
I tend not to give specific dietary advice but rather try to give you knowledge so that you can make informed decisions on your own.
But, today I am willing to give you one piece of advice, do not consume seed oils.
Start looking at the labels, and look for “vegetable oils”, or canola oil, soybean oil, sunflower oil, safflower oil, etc.
Now we have gone over:
The history of seed oils and how they snuck their way into our diets.
The link between diet and disease, and how seed oils are the most likely candidate for the increase in chronic disease.
The chemistry of fats, what makes seed oil fat different and why it might be detrimental to human health
The best nutritional studies ever conducted
We have one more post to go.
In the next post, we’ll dive into my thesis and look at how seed oils may be causing humans to prepare for starvation that never comes.
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Do today what makes your future self proud. And until next Sunday, have a great week!