Using a crossover experiment, I take a look at extra virgin olive oil versus butter.
This is part two of the olive oil vs. butter experiment.
My friend Dave Feldman had planned to do an experiment where he did a 4-week study of the effects of Extra Virgin Olive Oil (EVOO) and Butter, with all other sources of calories consumed remained constant. “Planned” because he ran into some problems and stopped. This is something I’ve done multiple times in the past so I decided to take over from Dave and run with it (besides, the guy can only do so many experiments a year). I’ll quote from Dave here:
One of the most common suggestions in lowering cholesterol (both total and LDL) is “replace saturated fat with mono and polyunsaturated fat”. This advice appears to have lots of evidence behind it. I’ve both read many studies and heard many stories that back up this advice, although individual results can vary.
In particular, I regularly hear one should “replace butter with extra virgin olive oil” where they can. Given the enormous popularity of both these sources of fat, I decided to set up an experiment to test each in isolation — and it’s going to be a bit ambitious.
Personally, I would much prefer to use Avocado Oil or Light Tasting Olive Oil, both have a light flavor that isn’t super terrible. Extra Virgin Olive Oil, on the other hand, tends to have a rather strong flavor that’s going to be a bit difficult to get through for 21 consecutive meals (twice). I suspect it’s going to be a bit like when I did Macadamia Nut Oil back in 2019, tolerable but no fun. As Dave said, it’s important that it be extra virgin olive oil because that’s kind of the “go-to” when people take out butter and other saturated fats from their diet, and the additional compounds that are in the extra virgin olive oil will likely come into play as well.
I’ll just go ahead and quote Dave for this:
As with the original design of this experiment I have outlined two categories of interest: lipid levels and inflammation markers. However, I’ll now be adding an additional test via Boston Heart that I’ve been waiting for — the Oxidized Phospholipids on apoB test (OxPL).
Something I’ve long speculated on is whether OxLDL would track tightly with OxPL. OxLDL is a pass/fail test — either the LDL particle has detectable levels of oxidation or it doesn’t. But the OxPL should show the degree of oxidation in those particles detected as an average for the total sampled. Thus, I think it will be an excellent test for risk and give us much more valuable information (but I do have some caveats, discussed below).
- Will EVOO interventions have lower relative total and LDL cholesterol levels (TC & LDL-C)?
- Will EVOO interventions have a greater oxidized LDL to total LDL particle count ratio (OxLDL/LDL-P)?
- Will EVOO interventions have a greater oxidized phospholipid to oxidized LDL particle ratio (OxPL/OxLDL)
Quoting Dave again:
As mentioned above, there are many factors that can influence cholesterol levels, particularly LDL. There is one effect that is rarely discussed in the literature but is of particular interest to me — how much we see particular types of dietary fat result in higher or lower oxidation per LDL particle.
In other words, are we seeing lower levels of LDL cholesterol because LDL particles are getting oxidized and cleared by scavenger receptors at a higher rate? There are many limitations to the experiment in how well it can provide evidence to this answer, but it might open the door.
We can’t easily know the true rate of clearance for OxLDL in vivo, or how much this is impacted by the degree of oxidation per particle. However, oxidized LDL particles are commonly understood to be cleared at a higher rate than unmodified LDL. So it will be meaningful data if we find a higher OxPL to OxLDL ratio in one intervention over the other.
Regardless, there will be quite a bit more data from all the other blood markers to provide comparisons that go well beyond lipids.
I checked blood ketones and glucose daily for the length of the experiment (except when I forgot), I also collected glucose readings using the FreeStyle Libre system. Based on the design that Dave concocted, I had the following blood tests done weekly by LabCorp:
I also went through the extra hassle to get some additional tests from Boston Heart Diagnostics as well. These include:
One of the main criticisms of Morgan Spurlock’s “Supersize Me” is that he absolutely refuses to release his food logs. You can’t take an experiment, even an N=1 experiment, seriously unless you can look at the data. Here are my own food logs for the entire experiment: Cronometer Full Nutrition Report (includes daily food logs and analysis) The data was collected using Cron-O-Meter.
OxPL – ApoB
LDL – P EVOO vs Butter
Lipids 1 – EVOO vs Butter
Lipids 2 – EVOO vs Butter
Triglycerides EVOO vs Butter
LDL – C EVOO vs Butter
Insulin
Until a proper write-up is complete, we were able to get Dave and Siobhan to record a video analyzing the results and talking about the next steps.
And here is a discussion about the second round of experiments.
Chris Bair is a technology and computer geek. He became involved in the nutritionally complete "future foods" movement in January 2014, originally with a conventional recipe and later switching to a high fat, low carb "ketogenic" variant on October 2014. In January 2015 he created the recipe for Keto Chow and released it without restriction for anyone to use, at the same time he began mixing the recipe up for people that wanted a finished product and has seen steady growth in the business every month since.