NOT since the days of Linda Blair’s Satanic possession in The Exorcist have heads spun so fast. In March a ground-breaking study in the Annals of Internal Medicine declared that saturated fat does not cause heart disease. What? (Or as my one time shaggy-haired crush would declare to the umpire: ‘You cannot be serious?’)
If you haven’t had your head buried in Gary Taube’s books over the last few years, then you’ll believe that one of the few established and universally accepted facts of diet and nutrition is that saturated fats are bad for us. Too much red meat, eggs and dairy products will make us fat and lead to a heart attack. Cholesterol from the fat will clog our arteries. Everyone knows this, it’s why we reach for the chicken and pasta and push away the plate laden with steak and eggs. Yet what if it just isn’t true?
This is the new reality to which the British Heart Foundation, which helped fund the research carried out by teams from Oxford, Cambridge and Harvard universities, is having to adjust too. On its website it currently runs the following paragraph: “At the moment UK guidelines encourage us to swap saturated fats for unsaturated fats. You might have seen reports about a recent study we helped to fund which suggests there’s not enough evidence to back the current UK guidelines on the types of fat we eat. We think more research is needed before suggesting any major changes to healthy eating guidance.”
The NHS is also sticking rigidly to what has become dietary dogma, stating on its website: “Eating a diet that is high in saturated fat can raise the level of cholesterol in the blood. Having high cholesterol increases the risk of heart disease. These practical tips can help you cut down on saturated fat.”
However, last week Dr Michael Moseley, the BBC presenter who introduced the 5:2 diet to the British public in his Horizon documentary, announced that after years of studiously avoiding saturated fats he was once again introducing them, in moderation, into his diet. In a recent article he said there was no convincing link between saturated fat and heart disease and that eating the right kind of fat can be both good for the heart and weight loss. A decade of studies has shown saturated animal fat does not cause obesity. If we eat fat it doesn’t automatically slot into our bellies and butts; instead our bodies break it down like any other food group. Yes, fat has more calories per gram than protein or carbohydrates but it also keeps us feeling fuller for longer. As a consequence fat and meat diets have proven more effective at weight loss than low-fat or carb-heavy diets.
The iron link between fat and heart disease was welded together in the 1950s in America where heart attacks had risen sharply. While smoking is now thought to have prompted the rise it was a scientist called Dr Ancel Keys who first postulated that there was a link between saturated fat and heart disease. When his first study was comprehensively dismantled by Jacob Yerushalmy, founder of the biostatistics department at Berkeley, instead of re-examining the evidence, Keys pushed back even harder and unveiled what became known as the “Seven Nations” study which published evidence from six countries in Europe and Japan showing a strong link between a high fat diet and heart disease.
Yet what has since emerged is that Keys had evidence from 22 countries and cherry-picked those that provided the most support for his hypothesis. He ignored nations such as France, West Germany and Sweden that had high-fat diets and low levels of heart disease and focused instead of countries such as Yugoslavia, Finland and Italy, which had high-fat diets and high levels of heart disease.
A new book, The Big Fat Surprise: Why butter, meat and cheese belong in a healthy diet, by Nina Teicholz, revealed that Keys’ study from Crete, which he held aloft as an example of a healthy low-fat diet, drastically undercounted their fat consumption by conducting the study during Lent, when meat was traditionally set aside, and instead of focusing on the diets of 655 men, he focused on only a few dozen. Keys’ flawed research was then quickly adopted by the American Heart Association, which in 1961 issued the first guidelines against saturated fat.
Our new fat-free diets have had unintended consequences. We now eat roughly 25 per cent more carbohydrates than we did in the past. The problem with overloading on carbs is they break down to glucose, which results in the body releasing insulin, which is very effective at storing fat. Studies now show it is diets overly high in carbs that are leading to obesity, type 2 diabetes and heart disease.
A word of warning, butter cream and cheese may be back on the menu but ca’ canny, they are still very calorie dense.
As Teicholz writes: “Every plank in the case against saturated fat has upon rigorous examination crumbled away.” The health establishment insists on still standing on those planks, but for how long will they hold?