Saturated fat – Friend or Foe?
Saturated fat, the stuff found in delicious foods like coconut, dark chocolate, high fat dairy products and fatty cuts of meat, has long been demonized in public health given its association with increased cholesterol and cardiovascular disease. However, a recent editorial on the topic claiming that reducing saturated fat in the diet has no effect on heart disease has caught the attention of the media and the public and has got people wondering whether they can consume all of the butter and bacon they want without worrying about the health of their hearts.
To understand this complex relationship between dietary fat and health, it’s important to know the difference between the two primary types of fat. Unsaturated fats are found in plant-based oils (like olive, canola, avocado, etc) and fatty fish, and are touted as heart healthy as they raise our “good” cholesterol (HDL) and lower our “bad” cholesterol (LDL). Saturated fats, on the other hand, have long been associated with heart disease because they increase total cholesterol (both the good and bad kind).
So, what does the research say? It turns out the scientific community is just as confused as we are! Some large studies have found no relationship between saturated fat and heart disease. Similarly, the Women’s Health Initiative (a large-scale study with over 45,000 women) found no difference in heart disease and total mortality between women eating a diet low in saturated fat versus those eating a more traditional, high fat diet. Why might this be? One reason may be due to the different types of LDL cholesterol – saturated fat has been shown to change the composition of LDL particles so that they are larger and can’t penetrate the walls of our arteries, meaning the heart is not affected.
However, bacon lovers should not rejoice just yet! Following the “pro-saturated fat” editorial that I mentioned above, many public health and nutrition experts spoke out against the paper and its findings due to its somewhat biased assessment and lack of scientific validity. For example, some high-quality research showing the benefit of a diet low in saturated fat for heart health was not included in the paper’s findings. Furthermore, the editorial did not take into account what was replacing the saturated fat in diets low in saturated fat. Studies show that when saturated fat is replaced with refined carbohydrates and sugars, the rate of heart disease and related mortality remains unchanged (which is the conclusion found in this editorial). However, when saturated fat is replaced with unsaturated fat, rates of heart disease decrease, leading experts to believe that increasing unsaturated fat in the diet is more likely to improve heart health than reducing saturated fat intake.
All clear? No, me either! So, what DO I recommend to my clients who are confused about how much fat and what type of fat they should eat? The research on this topic is clearly very conflicting – what we do know, however, is that all of the dietary patterns with strongly established positive health outcomes (like the Mediterranean diet) are low in saturated fat. Although, this doesn’t necessarily mean that foods high in saturated fat cause heart disease. The Mediterranean diet, for example, is also low in refined sugars and carbohydrates and high in fruits, vegetables, beans, lentils, and fish. This points to the notion that perhaps we should be moving away from vilifying some macronutrients and putting others on pedestals, and instead, focusing on overall dietary patterns and lifestyle habits that are proven contributors to health and wellness.