Tuesday, September 23, 2014
Saturated fat has long been demonised by doctors, but a growing body of evidence now suggests it may actually be HEALTHY…
How butter and cheese can keep you slim and even ward off diabetes by Jerome Burne
Many of us still choose skimmed milk rather than the full-fat in the supermarket, or choose low-fat spreads instead of butter. Such shopping habits are the result of decades of official advice to cut back on foods containing saturated fats because they clog our arteries and raise the risk of heart attack. But recently there have been the rumblings of a dietary revolution, with claims that saturated fat has been unfairly demonised.
Not only has changing to skimmed milk and similar products done little to halt the rise in obesity and type 2 diabetes, but major scientific trials have acquitted saturated fat of responsibility for heart disease.
In the past week, Swedish researchers found that eating full-fat dairy products slashed the risk of type 2 diabetes. In the study of more than 2,500 people, those who ate eight or more portions of high-fat dairy products a day had a 23 per cent lower risk of developing the condition than those who ate one portion or less.
Previous research has suggested that fat affects how the body breaks down sugar. And a Canadian Study, published in the journal Applied Physiology, Nutrition and Metabolism, found that eating dairy products such as cheese and cream may be associated with lower blood pressure and blood sugar – both factors linked to a lower risk of type 2 diabetes and obesity.
Researchers found that people with healthier blood test results had a type of fatty acid in their blood that is associated with eating diary food.
These are the latest in a line of reports that suggest we shouldn’t be shunning the full-fat option. In March, for example, an authoritative international study involving half a million people found that those who ate saturated fat were no more likely to develop heart disease than those who filled their trolley with low-fat yoghurts and fish.
‘Saturated fats do not cause heart disease,’ the researchers concluded.
Indeed, the new thinking is that removing saturated fat from our diet has been the problem, as it’s resulted in a major rise in our consumption of carbohydrates, especially sugar. This pushes up our blood sugar levels – and keeping blood sugar levels high for years is associated with type 2 diabetes and weight gain.
Those calling for a rehabilitation of saturated fat will be encouraged by a new book, The Big Fat Surprise: Why Butter, Meat and Cheese Belong In A Healthy Diet, by US science journalist Nina Teicholz.
‘In the past decade a number of trials comparing high and low-fat diets have shown that high fat is better for health,’ she says.
‘The evidence now suggests getting fat from red meat, eggs, whole-fat dairy or coconut butter are likely to be healthier than relying on vegetable oils.
One of the trials Teicholz is referring to – published this year in scientific journal PLOS ONE – involved patients with type 2 diabetes. Those put on a high-fat, very low-carbohydrate diet did much better than those on the standard diabetic diet, which is low in fat. They lost twice as much weight and were able to cut back on their medication four times faster.
‘The reality is that fat doesn’t make you fat or diabetic,’ says Teicholz. Her own moment of revelation came when the newspaper she was working for sent her to do restaurant reviews. ‘Suddenly, I found myself eating things that had hardly ever passed my lips before: pate, beef, cream sauces.
‘To my surprise, I lost 10lb that I hadn’t been able to shake for years, and my cholesterol levels didn’t change.
She spent the next ten years immersing herself in the scientific literature. ‘I was shocked to find egregious flaws in the science that has served as the foundation for nutrition policy,’ she says. ‘A policy which has all but forbidden these delicious and healthy foods for 50 years.’
Her research has found, for instance, how our love affair with the Mediterranean diet was encouraged by the opportunities for scientists and journalists to attend all-expense-paid conferences all funded by the olive oil industry. In fact, evidence that such a diet is heart healthy is not so strong. More dangerous, she claims, is the effect of demonising saturated fats has been to expose us to two far more toxic substances.
First, trans fats – the vegetable oils that have been artificially hardened into solids and which are now known to raise cholesterol levels, so are rarely used.
These have been replaced by a range of laboratory concocted fats. Yet these have been shown to increase the production of destructive the radical molecules in the body that can cause damage to cells and the genetic information they contain.
‘The track record or vegetable oils is highly worrisome,’ says Teicholz, ‘and not remotely what we bargained for when we gave up butter and lard.’
The drive to demonise fat began with US cardiologist Ancel Keys who, in the Fifties, identified it as an architect of heart disease. His theory was that fat raised blood levels of artery-clogging cholesterol. The cornerstone of his theory was his so-called Seven Countries study, which ranked the likes of the US, Japan, Finland and Greece by fat consumption, and showed the greater the fat intake, the higher the rate of heart attacks.
Critics have since pointed out that including different countries – such as France, Germany or Switzerland – could have produced the opposite result. Even so, Key’s hypothesis rapidly became official nutritional policy in both the US and Britain. One result was that saturated fats in processed food were replaced by an artificial form – trans fats.
These are made from unsaturated vegetable oils that are normally liquid at room temperature. To make them suitable for baking, they were made harder by bubbling hydrogen through them (hydrogenation).
But trans fats have a range of harmful effects, including raising ‘bad’ cholesterol and lowering the ‘good’ kind. In recent years manufacturers have been removing trans fats from their products. The scandal, Teicholz shows, is that even back in the Fifties, research had shown they might be dangerous.
But the industry still needs hard fats for baking. Its solution has been to use even more exotic chemistry to develop new ways of making vegetable oils solid.
Trans fats were also widely used in fast food and restaurants – where they’re now being replaced by polyunsaturated vegetable oils. But at high temperatures, these can break down to produce damaging free radicals.
In the Forties, researchers found these molecules can lead to cirrhosis of the liver and early death in animals. One of them, known as 3-MCPD, is being investigated as a potential carcinogen.
Meanwhile, Teicholz also claims that olive oil – a key component of the ‘heart-healthy’ Mediterranean diet – is not as wonderful as we’ve been led to believe. She says the positive image of olive oil owes much to $250 million-worth of EU public relations funding. Conferences held in the Nineties in beautiful Mediterranean locations encouraged far more scientific investigation and favourable media coverage of the Mediterranean diet than similar diets such as the South Beach and Atkins.
In fact, she suggests olive oil’s only virtue is that it doesn’t push up ‘bad’ cholesterol as much as saturated fat can. The Mediterranean diet itself comes out equally poorly in terms of heart protection: the data shows it is merely better than a standard low-fat diet, says Teicholz.
A low-fat diet has been damaging to women who’ve stuck to the advice faithfully. This is because it lowers their ‘good’ cholesterol more than men’s, argues Teicholz. The science is still uncertain, but the message seems to be full-fat milk may not be a guilty pleasure after all.
The Big Fat Surprise: Why Butter, Meat and Cheese Belong In A Healthy Diet, by Nina Teicholz (Scribe, €19).