Heart Disease and PUFAs
Riddle of the Sands
Heart Disease, we think, is a 'Disease of Modernity'. It seems to have been almost unknown before the 20th century, when a formerly very rare cause of death became a very common cause of death.
Autopsies of heart disease victims showed that the coronary arteries were full of fat. This build-up of fat in the arteries is known as atherosclerosis. The fat deposits clog the arteries that lead to the heart and eventually the system fails and you die.
That led to the condemnation of saturated fat, on the basis that saturated fats are solids at room temperature, even at body temperature. The theory was that the fats solidified out in the arteries and clogged them.
You can see how this was a plausible picture.
If you pour a load of hot animal fat down a drain it will most certainly solidify and clog the drain.
But it's nevertheless always struck me as really really very silly.
Saturated fats, animal fats, are extremely ancient, older than animals, they're probably as old as life. And I don't mean eukaryotic life, I mean the sorts of microorganisms that existed in the ancient seas of Earth, before there was oxygen in the air.
Saturated fats might even be older than life. They're the sorts of things which life is made out of, the sorts of things which life is designed around.
Storing food energy as fat is something all animals do. All animals have specialized cells to store fat. All animals have fat in their blood.
And we are omnivores. Eating a mix of carbohydrates and animal fats is what we're designed to do. Predators do not die of heart attacks because they have eaten the things they are supposed to eat.
There is lots of fat in your blood, and there should be. The fat in your blood and stored in your fat cells is nice and warm, it doesn't solidify out in your icy arteries.
Apart from the obvious evolutionary argument, how can a new disease be caused by an ancient food?
There are many examples of societies where people eat a lot of animal fat and don't get heart disease:
A classic example is the Maasai, an African tribe who still live pretty much the way their ancestors did:
The traditional Maasai diet consists of six basic foods: meat, blood, milk, fat, honey, and tree bark.
They eat a lot more saturated fat than almost anyone in the West. And yet they don't get heart disease.
Hell, the Polynesian islanders always ate an awful lot of coconuts, and the fat of coconuts is much more saturated than animal fat is. It will actually solidify at blood temperature.
But Polynesians before the introduction of modern food did not get heart disease.
Over the last century, we've repeatedly found uncontacted societies who don't appear to suffer from heart disease. And as soon as they adopt Western ways of living they do get heart disease.
There's also the 'French Paradox':
https://en.wikipedia.org/wiki/French_paradox
At least up until recently, the French didn't suffer nearly as much heart disease as other nations, despite eating a lot of saturated fat and holding on to that much longer than everyone else.
Which has led to all sorts of silliness, like believing that red wine protects people from heart disease. Or Olive Oil.
These days the French eat less saturated fat than they used to, and suffer from more heart disease than they used to.
I think we can pretty much rule out saturated fat as a cause of heart disease.
To be honest I don't know why anyone ever believed it. It was obviously not true to me when I was a boy in the 1970s. It doesn't seem any more true to me now.
But it's still a widespread belief even today.
A much better explanation for 20th century heart disease is the rise and fall of smoking. Smoking pretty much unambiguously causes atherosclerosis.
Smoking is a really bad idea. Set fire to a load of leaves and inhale the fumes coming off the fire, which contain hundreds of nasty chemicals that you were never designed to deal with. A lot of which are known poisons.
That's almost guaranteed to cause massive system-wide trouble. It would be a miracle if it didn't.
People who've never tried smoking pretty much universally hate it when they first try it. I still remember my first taste of pipe smoke when I was a little boy. It was utterly revolting and it put me off the idea for years, even though I've always rather liked the smell of tobacco fumes from a distance.
Unfortunately, if the leaves you're setting fire to contain nicotine, the smoke also produces a pleasant drug effect, and it is extremely addictive. You can get the taste for doing this very quickly. And it's famously very hard to stop doing it, or even to reduce the amount you do it.
This led to a situation after the second world war when almost half of people regularly smoked a lot of tobacco.
With immense effort we've managed to reduce the level of smoking from its peak of 50% in the 1950s, to around 15% today. And heart disease has also fallen.
So we've got a nice tidy narrative here for the epidemic of twentieth century heart disease:
Smoking became widespread, and that caused atherosclerosis, which caused heart disease. Then people realised that smoking was a very bad idea, smoking went out of fashion and the levels of heart disease reduced with it.
Saturated fat was an innocent bystander and got framed for the crime, but is in fact entirely blameless.
Unfortunately, there are some problems with this narrative too:
First, the Maasai actually have quite high levels of atherosclerosis! But it doesn't seem to cause heart disease. Their arteries have lots of atherosclerotic plaques, but it doesn't cause them any trouble. Their arteries don't get blocked. They don't get heart attacks.
Secondly, heart disease is quite widespread amongst non-smokers. Smoking certainly seems to make the problem worse, but if it's the cause, why do non-smokers die of heart attacks at all?
Thirdly, in the 1930s, heart disease was a vanishingly rare thing.
Nowadays, smoking rates are back to where they were in the 1930s, and although levels of heart disease have fallen considerably over the last fifty years, it's still the leading cause of death in England!
And also, of course, the French. Famed for their smoking. Didn't get heart disease much, back in the day.
And now this bombshell:
The Egyptian princess Ahmose-Meryet-Amon, who lived in Thebes (Luxor) between 1580 and 1550 BC and who is now known to be first person in human history with diagnosed coronary artery disease, lived on a diet rich in vegetables, fruit and a limited amount of meat from domesticated (but not fattened) animals. Wheat and barley were grown along the banks of the Nile, making bread and beer the dietary staples of this period of ancient Egypt. Tobacco and trans-fats were unknown, and lifestyle was likely to have been active.
It seems that there's an Egyptian mummy with really terrible atherosclerosis. She probably died of it, in her forties. At the least it looks like it made her very ill.
And you can't just dismiss this by saying: "Well, it's only one anecdote, one case proves nothing."
For one thing, we don't have that many preserved corpses from the distant past. If heart disease really was rare in the past it really is horribly unlikely that one of the preserved corpses would have had such a terrible case.
It's like finding a fossil. You can infer that there was probably a large population of the fossilised thing, precisely because fossilisation is such a rare event.
And in fact we have a number of Egyptian mummies, and quite a lot of them seem to show signs of arteries clogged with fat deposits.
So at that point, we have to believe that heart disease is not such a modern thing after all.
At the very least, amongst the sorts of people who got mummified in ancient Egypt, it was a common and serious disease.
I'm pretty sure that the ancient Egyptians weren't smoking tobacco. Tobacco was something found in the New World, and it didn't exist in Europe or Africa before 1600.
And without the nicotine to make smoking addictive, I find it difficult to believe that the Egyptians were smoking anything at all.
Well.
I don't think that Victorian doctors would have missed the fact that people were dropping dead all around them of heart disease.
We do actually have a few case reports of people who died of heart problems from before the 20th century, but it's described as something rare and strange. And people seem to have been genuinely terrified in the first half of the twentieth century, when it became common.
I think it must be true that heart disease really was vanishingly rare in most pre-modern societies, just like it's vanishingly rare in modern primitive societies. It's only when people start eating a modern Western diet that they get heart disease.
And I think it must be true that smoking causes heart disease, the statistical evidence is very strong.
And I think it must be true that heart disease was really common in Ancient Egypt, among the sorts of people who got mummified, at least.
So what could the answer look like?
u/NotMyRealName111111 on r/saturatedfat proposed the following solution:
Atherosclerosis is not the cause of heart disease.
Your arteries routinely get damaged, just like every other part of your body routinely gets damaged.
There are viruses, there are bacteria, there are parasites, there is wear and tear. There is smoking.
All these things damage the walls of your arteries.
And there is a repair mechanism. Just like when something damages your skin. It heals up.
Repairs are made, and usually, like scar tissue in skin, they're good repairs. You can tell that the injury happened, if you look carefully, but it's not a problem.
That's why people like the Maasai have atherosclerotic plaques but no heart disease.
PUFAs damage the repair mechanism.
The cholesterol, the foam cells, all that, getting into the artery walls, they're trying to fix the damage.
But they do a bad job, because they're contaminated with easily oxidised, unstable polyunsaturated fats.
Not at all the sorts of things that it is a good idea to have in the hot, oxygenated blood of an animal.
So the repairs need repairing, over and over again.
And the unstable, leaky, PUFA-filled atherosclerotic scar tissue builds up, thicker and thicker. Until eventually it blocks the artery, or starts shedding broken bits into the blood, causing chaos and death.
Atherosclerosis is not the cause of heart disease.
Atherosclerosis filled with PUFAs is.
This seems like it could work as an explanation, to me. Everyone everywhere has always had atherosclerosis. Scar tissue where damaged blood vessels have been repaired.
Smoking can cause it, disease can cause it, all sorts of insults can cause it, just like all sorts of things can damage your skin.
But usually it's not a problem. Very few people who didn't eat the modern diet, filled with PUFAs, suffered from heart disease.
That explains the heavy-smoking high-saturated-fat-eating French of my childhood, who noticeably did not suffer much from heart disease.
And it explains the mysteriously atherosclerotic exceedingly-saturated-fat-eating Maasai, who also don't suffer from heart disease.
And it explains pre-twentieth century England, where people ate traditional food with no PUFAs in it and lots of them smoked tobacco and yet they didn't hardly ever get heart disease.
And it explains what the hell your body is doing, wrecking its own circulatory system with cholesterol that it has just synthesised especially for the purpose. Because why on earth else would it be doing that?
And I think perhaps that there is nothing that it does not explain. At least I cannot think of anything.
What about our Egyptian Princess, and the rest of her social circle and their mysterious widespread serious heart disease?
Well that would be a real mystery.
Unless u/PeanutBAndJealous, also of r/saturatedfat, had not produced this book:
The Production and Use of Vegetable Oils in Ptolemaic Egypt
http://sites.dlib.nyu.edu/viewer/books/isaw_basp000006/5
Which I would not have believed existed unless I had seen it with my own eyes. Even now I am wondering if I've fallen for some AI-generated fake.
Now OK, this is Ptolemaic Egypt, 2000 years ago, not the Egypt of Ahmose-Meryet-Amon 3500 years ago. But the world changed a lot less between 1500BC and 0AD than it has done between 1900 and 2024.
It's very possible, I think, that Ahmose-Meryet-Amon was eating sesame oil (42% linoleic acid), or possibly safflower oil, which is apparently quite easy to manufacture by hand.
Wiki says:
https://en.wikipedia.org/wiki/Safflower
Safflower is one of humanity's oldest crops. It was first cultivated in Mesopotamia, with archaeological traces possibly dating as early as 2500 BC.
Chemical analysis of ancient Egyptian textiles dated to the Twelfth Dynasty (1991–1802 BC) identified dyes made from safflower, and garlands made from safflowers were found in the tomb of the pharaoh Tutankhamun.
Ahmose-Meryet-Amon did not smoke tobacco.
She did not eat much saturated fat. Indeed it seems that she was mostly vegetarian.
She did not eat much ultra-processed food.
Artisanal, organic, cold-pressed, hand-ground safflower oil was probably as close as it got, back in the day.
Modern medical "science", I think, would have thought that the princess was very wise to eat safflower oil. Full of heart-healthy omega-6 oils.
After all, wiki says:
In one review of small clinical trials, safflower oil consumption reduced blood low-density lipoprotein levels – a risk factor for cardiovascular diseases – more than those seen from butter or lard consumption.
Wise indeed.
I wonder what, in the small clinical trials, was happening to the low-density lipoproteins? Where could they have gone?
I couldn't possibly be that they were oxidising, could it?
Burning in the blood. Breaking apart into poisons.
Before they could even get where they were supposed to be going, to be used in repairs in damaged arterial walls.
I wonder if this princess Ahmose-Meryet-Amon is the smoking gun that proves that polyunsaturated fats cause heart disease.
They found mummies with tobacco leaves, and cocaine. There was contact with the old world, Atlantis was the stop between.
Excellent! Looking forward to reading that book!