To put it as simply as possible: no. There is absolutely NO EVIDENCE linking dietary intake of saturated fats with incidence of heart disease.
I know! This is so counter-intuitive, so contrary to everything we’ve been told. But a study published in the Archives on Internal Medicine in 2009 undertook a systematic review of every published medical study linking a wide variety of nutritional factors to heart disease.
And guess what they found?
You guessed it! There was no evidence — none — linking dietary intake of saturated fats with heart disease.
According to Dr. Briffa’s reporting on the study, the researchers applied the Bradford Hill Guidelines for judging weather or not a strong case for a cause/effect relationship existed between the nutritional factors studied and incidence of coronary heart disease.
If a nutritional factor met 4 or more criteria, they reported “strong” evidence supporting the link. Meeting 2 or fewer criteria made for a “weak” link.
And where did dietary intake of saturated fat score?
That’s right. It wasn’t even on their list!
Here’s Dr. Briffa’s summary and conclusion:
In other words, according to this review, there are no appropriately conducted randomised controlled trials to support the notion that cutting back on saturated fat is good for the prevention of heart disease. Add that finding to the one which shows no link between saturated fat and heart disease from cohort studies and where does that leave us? Well, the only logical conclusion to be drawn is that there really is no good evidence to support the widespread recommendation to reduce saturated fat intake for the sake of heart health.
Taken as a whole, I think the findings of this systematic review can be summarised as follows: a low fat, high carb diet is bad for the heart. And, again, a close inspection of the science gives us no reason at all to cut back on saturated fat.
In 2015, researchers did yet another systemic review and meta-analysis of all studies that linked dietary saturated fat intake to not just coronary heart disease, but also all-cause mortality, diabetes, and more. Yet again, they found no causal link between how much saturated fat study participants consumed with incidences of stroke, heart disease, diabetes, or death.
In fact, the 2015 meta-analysis found something interesting — a difference between healthy trans-fats from ruminants (like what’s in butter) vs industrial trans-fats. Industrial trans-fats were definitively linked to incidences of coronary heart disease (no surprise there!), while the naturally occurring trans-fats found in butter were inversely related to incidences of type-2 diabetes. In other words, people who ate more butter were less likely to contract type-2 diabetes!
So, when your friends or family chide you for your zealous use of coconut oil (92% saturated fat), butter from grass-fed cows (66% saturated fat), tallow from grass-fed cows (43% saturated fat), lard from foraged hogs (39% saturated fat), and other healthy fats, you don’t have to debate them — each wielding your own scientific sword. Instead, you can simply say “The evidence against saturated fats is simply not there.”
And you’ll be right!