Nutritional heresy no. 2: Saturated fat is not just harmless, it’s healthy
It’s only been bad for you since the 1950s.
Advice on saturated fat is usually paired in sentences with sugar. “Diets high in saturated fat and sugar will kill you”, or something along these lines, is a common caution. This is defamation of character. Saturated fat is a giver, not a killer, as anyone who really knows anything about nutrition will tell you.
As a rule of thumb, you can rest assured that anything that humans survived on, since coming down from the trees to live on the land, can’t be all that bad. Anything that only recently came out of a factory after undergoing a lengthy production process is probably very bad indeed. Stick with that and you’ve cracked the basics of human nutrition.
It’s all an illusion anyway
What’s so absurd about the general view of saturated fat is that it doesn’t actually exist as a single entity. Instead, there are lots of different saturated fatty acids, each with a unique structure and function. ‘Saturated’ means saturated with hydrogen, making the fat generally solid at room temperature (think butter or lard).
That’s the first thing that makes them healthy: because they are saturated with hydrogen, these fatty acids are stable and resistant to oxidation, unlike polyunsaturated fats like sunflower, soy and corn oil. When these unstable oils are refined, and heated, damaging free radicals are produced that can lead to damage and disease.
Many individual saturated fatty acids are so beneficial to health that you can purchase them in shops and on-line as supplements for therapeutic use. Yet if you get the same fats from your diet you are warned of dire consequences. Make of that what you will.
Saturated fats are made of chains of carbon atoms. They are usually classified as short-chain, medium-chain, or long-chain.
Meet the fats
Short chain fatty acids (SCFAs) have five or fewer carbon atoms. Medium-chain fatty acids (MCFAs) have 6-12 carbon atoms. Long-chain fatty acids (LCFAs) have 13 or more carbon atoms.
Let’s look at the SCFAs first, and what they do for you.
One of the reasons that the gut microbiome is so important to overall health is that friendly bacteria ferment fibre in food to produce SCFAs. In other words, saturated fat is made from fruit and vegetables by gut bacteria.
These saturated fats are particularly popular as supplements for people looking to restore gut health. They provide energy for the colon and reduce inflammation. They also help regulate metabolism and reduce the risk of developing many chronic diseases, including type 2 diabetes and obesity.
The liver will also make extra SCFAs, to keep your supplies topped up.
The medium-chain fatty acids (MCFAs) are used by the body to make the medium-chain triglycerides (MCTs) that are now so popular as supplements because they can be converted into ketones that provide fuel for the brain.
They are also used in the management of diabetes because they improve insulin resistance and glucose control.
‘Recent studies show that medium-chain triglyceride containing medium-chain fatty acids having unique physical and chemical properties is used to treat various diseases and syndromes, including mental health’
The main MCFAs are caproic acid, capric acid, caprylic acid, and lauric acid. Supplementing with these saturated fatty acids ‘can improve metabolic features as well as cognition in humans.’
MCFAs are antibacterial and are used therapeutically as a treatment against various pathogenic bacteria. They also have an antifungal effect and can reduce proliferation of the fungus Malassezia, widespread in hospitals. Nutritional therapists like me use them as part of a package to manage fungal infections such as Candida Albicans.
They also have other beneficial properties. Lauric acid increases HDL cholesterol and is found in high amounts in coconut. ‘Numerous reports’ have been published suggesting that lauric acid also has anticancer properties. Caprylic acid suppresses inflammation and regulates blood fats.
The long-chain fatty acids occur naturally in the diet. The body also makes them from other fatty acids. They take the form of triglycerides, phospholipids and cholesteryl esters and the main ones include stearic acid, palmitic acid and myristic acid. Their main role is to form part of the cell membrane, giving it structure.
How it all started
The prevailing nutrition wisdom since the 1960s – that saturated fat and cholesterol are harmful, and that we must make carbohydrates the centrepiece of our diets – is based on the work of one, highly influential man. That man was Ancel Benjamin Keys, an American biologist and pathologist who, in 1952, presented his ‘diet-heart hypothesis’, which proposed that saturated fat was responsible for raising cholesterol - and raised cholesterol caused heart disease.
Keys developed his theory after noting that people in Mediterranean countries had much lower rates of heart disease than Americans, and Americans ate a lot of fat. At first, he incriminated all dietary fat, but by 1957 he had narrowed his focus to saturated fat as the sole culprit.
As evidence to support his theory, Keys launched, in 1956, his Seven Countries Study, which was based on the diets, habits and physical measurements of middle-aged men from Italy, Greece, Yugoslavia, Finland, America, the Netherlands and Japan. The results were published by the American Heart Association (AHA) in 1970 and showed that a high consumption of saturated fat was directly associated with greater risk of having a heart attack. But what Keys failed to mention was how selective he had been about which countries were included in the group of seven: he excluded data from other countries that didn’t support his theory. Had Keys included the data from, for example, Germany, France and Switzerland, he would have obtained rather different results. In fact, his hypothesis would have vanished.
The diet-health hypothesis, based on the weakest of evidence, has never been proven. No causal link has ever been established.
Despite the crucial role that saturated fatty acids play in human health, dietary guidelines continue to focus on reducing saturated fat.
On the whole people have been generally compliant, and have switched to low fat versions of this and that. They have also replaced cooking with lard, butter, and tallow to using refined vegetable oils.
And look where that has got us. Rates of obesity and heart disease have soared since the 1970s.
‘Clinical trials have also failed to consistently find evidence that dietary saturated fat increases CHD risk or that replacing saturated fat with polyunsaturated fat reduces CHD risk’
Since those early, misleading studies were published, no research has ever supported the hypothesis that eating saturated fat causes heart disease. Some studies show the opposite. Full fat dairy foods, for example, have been found to have no effect on insulin sensitivity, blood fats or blood pressure. They do not increase cardiovascular risk.
‘Subsequent reexaminations of this evidence by nutrition experts have now been published in >20 review papers, which have largely concluded that saturated fats have no effect on cardiovascular disease, cardiovascular mortality or total mortality.’
Those early guidance givers were also keen to assure us that sugar was healthy. It gave you energy. It was virtually medicinal, and anyone who said otherwise was given short shrift. It took a long time for sugar to be outed as the food felon it truly is. Saturated fat on the other hand has not been brought to justice.
The continuing nonsense of the current dietary guidelines and the massive overprescribing of statin medications to reduce blood cholesterol levels will both be judged by history as the biggest scams in medical history.