You have long heard that fat is the enemy. Dietary recommendations over the past few decades have stated that fat should be greatly minimized—saturated fat in particular. Fat raises cholesterol, you’ve been told. A high-fat diet leads to heart disease, you’ve been led to believe.

The low-fat diet craze began in the late seventies with the recommendation to decrease saturated fat and cholesterol in the diet. (These recommendations were based on flawed studies and reasoning, a topic too long to cover here. I recommend the book Why We Get Fat by Gary Taubes. Or his New York Times article on the topic here.)

From there, the low-fat diet craze gained traction through the 80s and was in full swing in the 90s. We have been so entrenched in this message for so long—and lied to by established medical and nutritional agencies—that even today many people fear eating fatty foods. While Gary Taubes is one leading voice trying to turn the tables of our ingrained misperceptions, other scientists are stepping up to the plate to join him.

In a recent article published in the journal Open Heart, James DiNicolantonio, PharmD, sets the record straight about saturated fat. The main problem, he states, is that we are replacing saturated fat with carbohydrates and omega-6 fats, both of which contribute to poor cardiovascular health, the problem we are trying to avoid in the first place.

To highlight the detriments of a low-fat diet, he cited a 2008 study from the journal Lipids that found a low-carbohydrate diet reduced body fat, blood lipid levels, blood sugar and insulin levels, inflammation, and blood clotting factors all while improving good cholesterol (HDL) levels, while all of these markers worsened in people eating a low-fat diet.

After analyzing a number of randomized trials comparing low-fat versus a low-carbohydrate diet, DiNicolantonio concluded, “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.”

As for the replacement of saturated fat with polyunsaturated fats high in omega-6 (like corn oil, safflower oil, sunflower oil, and other similar vegetable oils), a 2010 meta-analyses of randomized controlled trials found that replacing saturated and trans fats with omega-6 fats without simultaneously raising omega-3 fats increases risk of death. This was confirmed in another recent meta-analysis in 2013.

That means that if you are avoiding saturated fats (found in full-fat dairy, butter, and red meat) by replacing them with vegetable oil without eating enough omega-3, then you are at greater risk of death than if you had eaten the saturated fat in the first place. Eye opening isn’t it?

DiNicolantonio summarized:

“The potential harms of replacing saturated fat with carbohydrates:

  • Increase in small, dense LDL particles. [these are the most dangerous LDL particles]
  • Shift to an overall atherogenic lipid profile (lower HDL-C, increase in triglycerides and an increase in the ApoB/ApoA-1 ratio).
  • Smaller improvements in glucose tolerance, body fatness, weight, inflammation, and thrombogenic markers.
  • Increased incidence of diabetes and obesity.

The potential harms of replacing saturated fat with omega-6 polyunsaturated fats

  • Increased risk of cancer.
  • Increased risk of coronary heart disease, cardiovascular events, death due to heart disease and overall mortality.
  • Increased oxidized LDL-C.
  • Reduction in HDL-C.”

It is going to take a whole lot of awareness to reverse the tide of fear about fat. But slowly, slowly, people are starting to get it. It’s all about eating the right fats and not overcompensating with nutrient-poor carbohydrates.