Dr Maryanne Demasi. Picture: ABC TV

ABC’s Catalyst reporter Dr Maryanne Demasi last night finished up her two-part expose of what many medical specialists are calling the “cholesterol myth”.

One of the most cherished health assumptions of the modern era – that high cholesterol levels and saturated fat consumption lead to heart disease and death – may be fundamentally based on a single dodgy chart from the 1950s.

Bad news for the multibillion dollar food industry that’s dined out on the healthy heart approach, but if that’s come at the risk of us all ignoring greater perils, then so be it.

Dr Demasi’s “Heart of the Matter” wrapped up last night dealt with the issue of anti-cholesterol drugs known as statins, and the possibility the benefits of their use has been exaggerated.

It ran on the ABC despite a plea earlier this week from the chair of the Australian Advisory Committee on the Safety of Medicines to pull the episode, citing a danger that it could cause people not to take their anti-cholesterol drugs.

Take from it what you will. The ABC made it clear that the report was not intended as any form of medical advice.

But it was undeniably riveting. Here’s a breakdown of the key points:

1. Cholesterol is essential for life. Picture: Getty Images It's a major component of brain and nerve tissue, and central for hormone production. Virtually every cell in your body makes it. 2. Eating fat causes heart disease. Picture: ABC TV The idea that saturated fat clogs your arteries by raising cholesterol was first kicked around in the '50s by American nutritionist Ancel Keys. He noted soaring rates of heart disease after World War II and compared the rates of heart disease and fat consumption in six countries. Result? The more fat people ate, the higher the rates of heart disease. Except, there was just one problem. 3. Keys withheld data for 16 other countries. Picture: ABC TV Researchers later plotted Keys' data for all the countries he studied - 22 of them. And guess what? The correlation wasn't so perfect. Dr Michael Eades says Keys excluded countries that didn't fit his hypothesis.

'He more or less cherrypicked countries. You could show just the opposite. You could show that the more saturated fat people ate, the less heart disease they had, if you cherrypicked the right countries.'

But Keys had done enough to score a position on the American Heart Association's advisory panel. Soon all Americans over the age of two were being told to go on low-fat diets. 4. Follow-up trials couldn't replicate Keys'result. Picture: ABC TV Six in particular were carried out between 1960 and 1975. All failed to confirm that you could live longer by reducing saturated fat in your diet or reducing total fat in your diet.

Later, another two trials, costing over $250 million and involving hundreds of thousands of patients, failed to prove that lowering saturated fat could lower your risk of dying from heart attack.

Instead of admitting the result, the authorities responded by claiming they must have done the study wrong. 5. Even Australia's National Heart Foundation admits evidence is 'limited'. Picture: ABC TV They could only cite one study to Dr Demasi which showed only certain types of saturated fat could raise bad cholesterol. But it also raised good cholesterol. In the end they concluded - 'We agree that we are limited by the evidence base, available at this time.' 6. Diet has very little influence on your blood cholesterol in the long term. Cardiologist Ernest Curtis. Picture: ABC Cardiologist Ernest Curtis says the reason for that is that your body manufactures 80% to 90% of your cholesterol. Very little of it comes from the diet. And if somebody cuts all the cholesterol out of their diet, their body will simply start making a little bit more to bring it back up into the range. 7. The longest study on heart disease began in 1948. It's still going. Picture: ABC More than 5000 residents of Framingham, Massachusetts are still having their health monitored. The data has found that habits people pick up at an early age - like smoking and stress - can affect heart health.

But 30 years later, researchers found that by the time residents reached their late 40s, there was no correlation between cholesterol levels and heart disease. 8. In fact, after the age of 47, high cholesterol was shown to be probably protective. Picture: ABC 9. Then there's the Lyon Diet Heart Study. Picture: Getty Images This study charted results of two groups of dieters. After several years, it emerged that those on the Mediterranean diet had a whopping 76% less deaths from heart attacks.

But their cholesterol levels didn't budge. Both groups had the same cholesterol levels, except one group just stopped dying. So, so much for the relationship between cholesterol and the risk for heart disease. 10. THEORY - Fat and cholesterol block arteries. Picture: ABC Contrary to popular belief (and advertising), neither saturated fat or cholesterol deposit on the artery wall like sludge in a pipe.

If an artery wall is damaged, the body responds by building a cap over the plaque. The plaque often contains cholesterol, along with bacteria and calcium. If it bursts, a clot can form.

Hence when doctors study the clot, they often find cholesterol.

Cardiologist Stephen Sinatra says blaming cholesterol for causing plaques is like blaming firemen for causing fires, just because they're always at the scene. 11. THEORY - The real cause of arterial damage is inflammation. Picture: Getty Images The number one indicator for inducing inflammation is insulin. More and more doctors are now coming around to the fact that sugar is the real enemy.

In the '60s, British physician John Yudkin claimed exactly this. Keys publically discredited Yudkin's theory and ridiculed it throughout the 70s. Society took his side - the idea that sugar could cause heart disease was clearly ludicrous.

Keys was helped by an appearance on the cover of Time magazine. 12. The other cause of inflammation Picture: Wikipedia Omega-6 oils. Margarine is the perfect example.

Polyunsaturated fats such as vegetable oils are inflammatory because they're very prone to free radical attack - oxidation. Oxidised cholesterol is the cholesterol often referred to as “the bad cholesterol”.

Saturated fats, like butter, are inert fats. When you cook with them, they don’t pick up free radicals. 13. Why the Mediterranean diet worked Picture: Wikipedia Because of the high omega-3 content in seafood. Omega-3s are thought to counter the inflammatory effects of omega-6s. Hence fish with a high oil content, such as salmon, are recommended as an essential part of a healthy heart diet.

Now watch Heart of the Matter Part 2 and learn why statins may not be the cure we think they are.

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