After reviewing nearly 80 studies involving more than half a million people, researchers at Cambridge University found that saturated fat doesn't cause heart disease.
The study, published in the journal Annals of Internal Medicine, also shows that 'good' fats do not lower the risk of heart attack.
So is it time to stop demonising fat?
"It's not saturated fat we should worry about," says Dr Rajiv Chowdhury, lead author of the study. "It's the high-carb or sugary diet that should be the focus of dietary guidelines."
Carbs and sugar contain more artery-clogging particles than saturated and non-saturated fat, and the researchers suggest these should be the focus of new dietary guidelines.
In October 2013, cardiologist Aseem Malhotra, who works at Croydon University Hospital in London, published a report in the British Medical Journal saying there's no link between saturated fat intake and cardiovascular risk. "Indeed, recent prospective cohort studies have not supported any significant association between saturated fat intake and cardiovascular risk. Instead, saturated fat has been found to be protective."
Malhotra believes that our 'fat obsession' comes from "The Seven Countries Study", which started in the late 1950s and was published in 1970. It was the first study to investigate the correlation between diet, lifestyle and heart disease in different countries, and it established that saturated and trans fats intake was associated with higher mortality rates. It was also the first one to high-light the many benefits of the Mediterranean diet.
The results of Chowdhury and Malhotra's studies, however, shouldn't be an excuse gorge butter and cake. "It would be unfortunate if these results were interpreted to suggest that people can go back to eating butter and cheese with abandon," said Alice H. Lichtestein, a nutritional biochemist at Tufts University, to The New York Times.
Over the past few years we've been advised to cut fat intake to 30% of total energy and saturated fat to less than 10%, and we should stick to those guidelines until new ones are published.