A Word from Dr. Kirby – Consumption of Saturated Fats Still Not Healthy

I am putting this article forward because of the impression many people now have that research has recently exonerated the consumption of saturated fats as a major factor in the development of heart disease and strokes.
By saturated fats I am referring to those present in meats (especially beef and pork), dairy products, and many snack foods. They are also present in some plant-derived oils such as palm oil and coconut oil.
The following is a summary of a report commissioned by the American Heart Association to review all of the pertinent scientific literature.
It indicates that a false impression was made when studies examining the effect of low fat diets on the incidence of heart disease showed no change. The reason for the lack of change was that the fats were replaced by large amounts of sugar-containing foods and refined carbohydrates. These changes in our diets are thought to be a major contributor to obesity and type 2 diabetes which are themselves contributors to heart disease.
The best advice when lowering consumption of these foods is to replace them with foods containing healthy poly- or mono-unsaturated fats such as those found in nuts and to increase the consumption of fresh fruits and vegetables and whole grain cereals and pasta.
Here is the summary of the report:

Dietary Fats and Cardiovascular Disease: A Presidential Advisory From the American Heart Association

Originally published Circulation. 2017;136:

Cardiovascular disease (CVD) is the leading global cause of death, accounting for 17.3 million deaths per year. Preventive treatment that reduces CVD by even a small percentage can substantially reduce, nationally and globally, the number of people who develop CVD and the costs of caring for them.

This American Heart Association presidential advisory on dietary fats and CVD reviews and discusses the scientific evidence, including the most recent studies, on the effects of dietary saturated fat intake and its replacement by other types of fats and carbohydrates on CVD. In summary, randomized controlled trials that lowered intake of dietary saturated fat and replaced it with polyunsaturated vegetable oil reduced CVD by ≈30%, similar to the reduction achieved by statin treatment. Prospective observational studies in many populations showed that lower intake of saturated fat coupled with higher intake of polyunsaturated and monounsaturated fat is associated with lower rates of CVD and of other major causes of death and all-cause mortality. In contrast, replacement of saturated fat with mostly refined carbohydrates and sugars is not associated with lower rates of CVD and did not reduce CVD in clinical trials. Replacement of saturated with unsaturated fats lowers low-density lipoprotein cholesterol, a cause of atherosclerosis, linking biological evidence with incidence of CVD in populations and in clinical trials.

Taking into consideration the totality of the scientific evidence, satisfying rigorous criteria for causality, we conclude strongly that lowering intake of saturated fat and replacing it with unsaturated fats, especially polyunsaturated fats, will lower the incidence of CVD.

This recommended shift from saturated to unsaturated fats should occur simultaneously in an overall healthful dietary pattern such as DASH (Dietary Approaches to Stop Hypertension) or the Mediterranean diet as emphasized by the 2013 American Heart Association/American College of Cardiology lifestyle guidelines and the 2015 to 2020 Dietary Guidelines for Americans.