Is saturated fat bad for the heart?
Heart disease is a major cause of death and disability in Australia and places a substantial financial burden on the healthcare system.
Coronary heart disease (CHD) is a disease in which plaque (a waxy substance) builds up inside the coronary arteries, which supply oxygen rich blood to the heart. This build up can cause a blockage over time that limits blood supply to the heart leading to the increased risk of a heart attack.
Guidelines on the prevention of heart disease consistently recommend limiting saturated fat intake. Foods high in saturated fat include biscuits, cake, processed foods and many forms of fast food. Many people limit saturated fat intake but replace it with low quality carbohydrates, which promote increased risk of obesity and diabetes.
A comparatively less studied area is the association of individual saturated fatty acids (SFAs) – like lauric, myristic, palmitic and stearic acids – and the risk of CHD.
Researchers analysed associations between intake of individual SFAs and CHD and also the change associated with replacing individual SFAs with healthier macronutrients.
Data from more than 70,000 women and more than 40,000 men were analysed. Participants filled out food frequency questionnaires at baseline in 1980 and every four years after. The questionnaires ascertained how often they consumed specific foods in the past year.
From these, researchers calculated intake of SFAs, polyunsaturated fat, monounsaturated fat and trans fats. Total CHD was also recorded including non-fatal and fatal heart attacks. Participants were followed up for between 21 and 25 years.
The results showed increased risk of CHD associated with intake of the major individual SFAs. Furthermore, this study found that replacing intake with polyunsaturated fat, whole grain carbohydrates or plan proteins was associated with a reduction in the risk of CHD.
The results of this study confirm the need to limit saturated fat intake as much as possible. Replace saturated fat with healthier macronutrients likes vegetables and whole grain carbohydrates.
Last Reviewed: 12/11/2019
Norman Swan Medical Communications
Zong, G et al. (2016). Intake of individual saturated fatty acids and risk of coronary heart disease in US men and women: two prospective longitudinal cohort studies. BMJ doi: 101136/bmj.i5796.