Public health warnings needed over sugar, says US scientist

‘Compelling argument can be made for lack of evidence in support of low-fat diet’

Writing in the journal Open Heart, leading US cardiovascular research scientist Dr James DiNicolantonio said a “compelling argument can be made for the general lack of evidence in support of a low-fat diet”. Advising people to replace saturated fat with carbohydrates or omega 6 polyunsaturated fats was not supported by scientific research, he said. Photograph: Wojciech Pacewicz/EPA

Writing in the journal Open Heart, leading US cardiovascular research scientist Dr James DiNicolantonio said a “compelling argument can be made for the general lack of evidence in support of a low-fat diet”. Advising people to replace saturated fat with carbohydrates or omega 6 polyunsaturated fats was not supported by scientific research, he said. Photograph: Wojciech Pacewicz/EPA

Thu, Mar 6, 2014, 10:12

Diets low in saturated fat do not prevent heart disease or improve health and instead public health warnings need to be issued over sugar, a leading scientist has said.

The fear that saturated fat raises cholesterol is “completely unfounded”, while the current recommendations to follow a low-fat diet are based on flawed evidence, he added.

Writing in the journal Open Heart, leading US cardiovascular research scientist Dr James DiNicolantonio said a “compelling argument can be made for the general lack of evidence in support of a low-fat diet”.

Advising people to replace saturated fat with carbohydrates or omega 6 polyunsaturated fats was not supported by scientific research.

“A change in these recommendations is drastically needed as public health could be at risk,” he said, adding that the rise in diabetes and obesity over recent years correlated with the increase in carbohydrate consumption, “not saturated fat”.

He went on: “There is no conclusive proof that a low-fat diet has any positive effects on health. Indeed, the literature indicates a general lack of any effect (good or bad) from a reduction in fat intake.

“The public fear that saturated fat raises cholesterol is completely unfounded, as the low-density lipoprotein particle size distribution is worsened when fat is replaced with carbohydrate.”

Instead, he said the culprits of increasing poor health are diets high in carbohydrate and sugar - and a public health campaign is “drastically needed to educate on the harms of a diet high in [these foods]”.

Dr DiNicolantonio said the idea that fat causes heart disease was based on a flawed 1950s study which used data from six countries but excluded data from another 16.

This study “seemingly led us down the wrong ‘dietary road’ for decades to follow”, he said.

The initial Dietary Goals For Americans, published in 1977, proposed increasing carbohydrates and decreasing saturated fat and cholesterol in the diet.

Dr DiNicolantonio said: “This stemmed from the belief that since saturated fats increase total cholesterol (a flawed theory to begin with) they must increase the risk of heart disease.”

Experts also believed the diet would lead to less obesity and diabetes - when the exact opposite was true, he added.

Furthermore, evidence shows that a low-carbohydrate diet - as opposed to a low-fat diet - actually improves cholesterol.

“From these data, it is easy to comprehend that the global epidemic of atherosclerosis, heart disease, diabetes, obesity and the metabolic syndrome is being driven by a diet high in carbohydrate/sugar as opposed to fat - a revelation that we are just starting to accept,” Dr DiNicolantonio said.

The idea that replacing a combination of trans-fats and saturated fats with omega 6 polyunsaturated fats (without a corresponding rise in omega 3 fatty acids) has also been shown to increase the risk of death, including from cancer and heart disease, he added.

In an accompanying podcast, Dr DiNicolantonio said: “We need a public health campaign as strong as the one we had in the ’70s and ’80s demonising saturated fats, to say that we got it wrong.”