Eating foods that contain saturated fat is thought to increase blood cholesterol levels, which can increase the risk of heart disease. As a result, health professionals recommend following a diet low in saturated fat to reduce this risk. But a leading US cardiovascular scientist says that adopting such a diet does not curb heart disease or prolong life.
In an editorial recently published in the BMJ journal Open Heart, Dr. James DiNicolantonio says the consumption of saturated fat was first criticized back in the 1950s, when a researcher found an association between fat calories as a percentage of total calories and death from heart disease.
But Dr. DiNicolantonio says the findings of this research were flawed. He notes that the study author reached his conclusion using data from only six countries, choosing to exclude data from 16 countries that failed to fit his hypothesis.
However, Dr. DiNicolantonio says this data "led us down the wrong 'dietary road' for decades to follow."
According to him, this data led to the widespread belief that since saturated fat raises total cholesterol - a theory he says is also flawed - it must increase the risk of heart disease.
On the back of this, health professionals began recommending a reduction in saturated fat intake and an increase in refined carbohydrates or polyunsaturated fats as an alternative.
Dietary recommendations 'could be putting public health at risk'
The American Heart Association (AHA) recommend limiting the consumption of saturated fat to less than 7% of total daily calories - the equivalent of 16 g of saturated fat a day. The organization also recommends replacing saturated fat with monounsaturated or polyunsaturated fat.
But Dr. DiNicolantonio says there is insufficient evidence to suggest that reducing saturated fat intake helps to reduce the risk of heart disease, and consuming refined carbohydrate or polyunsaturated fat, such as omega-6, may even increase the risk of heart disease and other conditions.
Dr. DiNicolantonio notes that there are two types of (low-density lipoprotein - LDL) cholesterol - large buoyant LDL particles (pattern A) and small, dense LDL particles (pattern B).
While a low-fat diet may reduce the LDL in pattern A, he says that increasing refined carbohydrate intake may increase distribution of LDL in pattern B. This can increase risk factors for heart disease, such as obesity and diabetes.
Furthermore, Dr. DiNicolantonio notes that replacing saturated fat with omega-6 polyunsaturated fat may increase the risk of cancer, coronary heart disease, heart disease-related death and overall mortality.
He told Medical News Today:
"The increase in the prevalence of diabetes and obesity in the US occurred with an increase in the consumption of refined carbohydrate, not saturated fat. There is no conclusive proof that a low-fat diet has any positive effects on health."
Due to the lack of evidence linking the consumption of saturated fat to heart disease, Dr. DiNicolantonio says a change in current dietary recommendations is "drastically needed," as they may be putting public health at risk.
He told us that instead of adopting a low-fat diet, people need to start eating "real food" that is unprocessed. He recommends eating organic nuts, vegetables, fruits and meat from cows set to pasture - cows that eat grass that is never grain finished.
Furthermore, Dr. DiNicolantonio told us there needs to be more research into what specific foods are the healthiest.
"Currently, a large amount of the data in the literature have tested varying levels of macronutrients vs. another (for example, low-carb vs. low-fat), but now we need more data on the health benefits of different foods," he said.
This is not the first study to question the association between saturated fat and heart health. Last year, Medical News Today reported on a review from a UK cardiologist who said that the role of saturated fat in heart disease is a myth.
Aseem Malhotra, of Croydon University Hospital in the UK, says that since the general public has followed recommendations to reduce the consumption of saturated fat, cardiovascular risk has increased.