Here is a question that I’ve been asking… I was thrilled to see it answered on Robb Wolf’s blog. Check out the original post here.
Question #1 – Answered by – Stephanie Greunke, RD
If saturated fat is supposed to clog your arteries when you consume it, then how exactly does it do this? And if it doesn’t, then why has that message been so heavily hammered down our throats for the past decade?
“Artery-clogging saturated fat.” You see those words smoothly strung together throughout almost every piece of health literature and yet, what evidence does that truly play upon? Those words get to me almost as much as the “healthy whole grains” that is stamped all over food packages and advertisements.
This is a great question and is the cause of a lot of controversy within the Paleo realm. While there are certainly some Paleo folks out there that still maintain that saturated fat may increase LDL plasma levels, resulting in possible cardiovascular disease, many Paleo advocates have adjusted their mindset more in favor of saturated fat, provided a few other variables are in order. Those who are not so enthused by saturated fats will most likely agree that saturated fat is not as big of a demon when one is consuming lean meats and adjusting other dietary and lifestyle factors to ultimately decrease systemic inflammation.
The kicker with saturated fat is whether or not the LDL cholesterol is oxidized or not. The “artery-clogging” plaque production is mediated by oxidized LDL. The oxidized LDL then goes through a process where it becomes a fibrous cap. If this fibrous cap gets broken down by, you guessed it – lectins and chronic inflammation, that’s when the ischemic events take place. So what should really be our goal? Reducing inflammation through a clean, Paleo diet, abstaining from smoking and excessive exercise, minimizing alcohol consumption, and engaging in stress-lowering habits. When these variables are in order, we do not need to be so caught up with saturated fats.
Our blood vessels can become damaged in a number of ways (free radicals, viruses, structural weakness, lectins, glycemic load, sleep, stress, immune response), so the evidence that the LDL plasma levels are increased mainly by saturated fatty acids must be taken with a grain of salt. The universal advice to switch to wild meat sources emphasizes not only a lower amount of saturated fat, but also a favorable n-6:n-3 ratio.
So where did all of this madness and mind-washing about saturated fat come from? Look no further than to the infamous Ancel Keys and his Seven Countries Study*. While seven countries saw an increase in heart disease cases that corresponded with increased fat consumption (hence the name of the study), he “accidentally” left out some very important details about the other fifteen countries so the evidence was in his favor. The study is ultimately a correlation, not a causation, but the outcome of the study became mainstream and was warmly accepted into the scientific community. Since no other well-designed studies can support the Lipid Hypothesis and any studies that do not support it get rejected and disregarded for credibility, we all stand here today reading about “artery-clogging” saturated fat day in and day out.