Over the last 50-60 years, no other nutrient has been demonised quite as much as saturated fats. This attitude stemmed from the diet-heart hypothesis proposed by physiologist Ansel Keys in the 1950s. Keys based his assumptions on observational studies that showed that people who consumed high amounts of saturated fat had higher rates of death from heart disease. The hypothesis postulated that saturated fat raises LDL (bad) cholesterol in the blood, which then supposedly lodges in the arteries (causing what is known as arterial stiffness) and causes heart disease. But has this hypothesis been validated by research? The answer is, actually, no.
Moreover, here’s what you need to know about saturated fat and the tangible benefits associated with its consumption.
60% of your brain is made of fat. 50% of the fat in your brain is saturated and critical for cognitive function
Cell membranes are 50% saturated fat
Saturated fats are the building blocks of many key hormones
Saturated fats can increase HDL, the “good cholesterol”
Consuming a low-carb high-fat diet can increase LDL particle size, which reduces risk of heart disease
Despite the 60+ years of reputation as the driver of cardiovascular disease (CVD), certain saturated fats are, in fact, good for your cardiovascular health. This 10-year study found no connection between the total intake of saturated fat and the risk of heart disease. This meta-analysis of 18 different observational studies looked at the levels of pentadecanoic and heptadecanoic acids, both of which are saturated fats found in dairy, and concluded that higher blood levels of these nutrients were actually linked to a lower risk of heart disease. Stearic acid, one of the most common saturated fatty acids found in meat, is associated with improved body fat, improved mitochondrial function, and weight loss.
There have been few studies on saturated fat intake and its effect on human bones, and previous conclusions about its adverse effects on bone density were mostly based on studies involving mice. More recent studies show that saturated fat intake may protect against osteoporosis.
All in all, saturated fat that comes from healthy natural sources such as dairy, meat, and nuts, is not the villain it’s been made out to be. Clearly, every person is different, and for some a ketogenic diet may lead to skin inflammation and other unpleasant reactions, while for others it can be the best solution for their health and appearance.