Butter Not Like a Statin After All?

I began my original butter experiment without a hypothesis about the effects of butter on cholesterol. I was tracking blood lipids so that I could identify any possible adverse reactions. After initially seeing a positive change, the numbers started to go the wrong way, with HDL dropping and non-HDL going up. At the same time, I had switched from the Kerrygold butter I usually used to a local brand from my farmer's market. It was supposed to be "100% grass fed," but it did not have the deep yellow hue of the Kerrygold, so I suspected it could be responsible for the adverse results. After a day or two using an Icelandic brand (Smjor), I decided for the remainder of the experiment to test only Kerrygold butter. A few days after the switch back, the numbers moved back in the positive direction. I tracked for a few more weeks and then reported my initial results here.

After the original post, I spent about three more weeks on the same diet (1/2 stick of Kerrygold butter per day), followed by three weeks of butter elimination (during this elimination phase, there was some increase in coconut oil as a partial substitute for the butter calories). Finally, I went back on a high-butter diet for an additional five weeks. During this last phase I decided to double down and eat a full stick of Kerrygold butter every day (about 112 grams of butter and 90 grams of fat). The diets were otherwise similar, though I was likely consuming more total calories during the high-butter phases. Data points were generally taken weekly, on Sunday afternoons (not fasted, but I don't believe it makes much difference, since I am not measuring triglycerides).

Based on the additional data I can report that the addition of butter to my diet may have increased my HDL cholesterol. However, it has not had a convincing long-term effect on my non-HDL cholesterol. The HDL remains elevated from before, but non-HDL readings are consistent with my average numbers over the past three years or so. My working hypothesis at this point is that the change in non-HDL I observed originally was a temporary disturbance of homeostasis. This may have been due to the butter or to another unknown cause.

I also believe this data suggests that different brands of butter can have different effects on cholesterol values. I will show this data below, though given the design of this experiment, I will not be able to prove it without a follow-up experiment. However, I am satisfied with my original concern, which is that the addition of a good brand of butter to my diet does not seem to have any measurable adverse effect on cholesterol measurements.

Results

The additional data points are shown in the two plots below. The four green points show the data that was dropped from the original data set because I was not using Kerrygold butter. The last five points are for the latest diet where I am eating a full stick of butter per day.

HDL measurements over time. Red points indicate control. Blue and green points indicate experimental group with consumption of at least 0.5 sticks of butter per day for at least 7 days prior to testing (blue=Kerrygold). No statistically significant difference in control vs. experimental measurements when green points are included. Trend line is for red points only.

Non-HDL cholesterol over time. No statistically significant difference between control vs. experimental measurements when green points are included. Trend line is for red points only.

The next two plots show the same data, zoomed in to show points from the beginning of the original butter experiment to the present time. The three red points are the latest butter-elimination phase.

Trend line for blue points.

Trend line for blue points.

Overall, I think there is some basis for concluding that added butter is having a positive effect on HDL, although the results are not statistically significant when the green points are included. However, it is also possible that some other factor is concurrently causing my HDL to increase.

The trend towards positive HDL outliers has continued in the butter dataset and is especially strong in the latest readings where a full stick per day is consumed, suggesting a dose-response relationship. My last three readings are all greater than 100, which is the meter's measurement limit for HDL cholesterol. Since I am computing non-HDL cholesterol as Total minus HDL, this measurement limitation will inflate the non-HDL points by an indeterminate amount at the same time as it underestimates HDL. The highest reading ever recorded in the control dataset is 83, while the butter dataset has 5 readings above that level and three above 100.

The non-HDL numbers do look like noise at this point, except for the original cluster of low readings when the original butter experiment began. There probably was some underlying cause for that, though it is clear to me that if the butter had anything to do with it, the effect was temporary.

Note also that there are several negative outliers for HDL in the non-Kerrygold butter set. This suggests that different brands of butter can have different effects on cholesterol measurements. This phenomenon may warrant further study.

What's the Take Away?

Okay, I hear what you're saying: "Greg, that's a heck of a lot of colored dots. So what?" I think the bottom line is, I'm eating a whole stick of butter every day and my lipid profile has either stayed the same or gotten a little better. Works for me.

Measurement Accuracy

During this experiment, I observed that the CardioChek PA seems to be very accurate at measuring HDL, but much less accurate at measuring total (and therefore non-HDL) cholesterol. One of the newly collected data points shown above is the result of a VAP cholesterol panel ordered by my doctor. The same morning as the blood draw for that test, I took three successive readings of HDL and total cholesterol with the CardioChek PA. The VAP test showed an HDL of 68 and non-HDL of 233. The three HDL measurements on the CardioChek PA averaged out to 68, same as the VAP result, with a standard deviation of only 1.7%. For non-HDL, on the other hand, the average was 191 with a standard deviation of 15%. Compared to the 233 non-HDL measured by VAP, the CardioChek PA was off by 18% even when three separate measurements were averaged.

Therefore, variance seen in my HDL readings over time suggests that real changes are taking place in my body. However, variance in my non-HDL measurements will be substantially the result of measurement error in addition to physiological changes. To put this in perspective, the standard deviation of all of my non-HDL measurements over the last 2+ years taken together is only 15.8%, barely higher than the meter's built-in measurement noise.

The CardioChek also sells test strips for direct LDL measurement. I will probably check those out at some point, as they may prove to be more accurate than the total cholesterol strips.

Next Steps

Ideally, self-experimentation would be based on biomarkers that can be measured accurately and cheaply, and that quickly reflect real health trends. Blood sugar measurements are very useful in that regard, because it only takes one finger prick an hour after a meal to obtain useful information about your body's response to carbohydrates. Over the course of this experiment, I've become skeptical of the value of cholesterol measurements as a target of self-experimentation. Given the meter's built-in measurement noise and the long half-life of circulating lipoproteins, it takes weeks or months for changes to be clearly evident. That makes it difficult to do useful experiments.

My most pressing health goal until the end of 2012 is a 405 pound deadlift. High cholesterol and extra calories from butter are probably going to help me achieve that goal, so I will be putting my cholesterol investigations on hold for the time being. In the mean time I do have a few other experiments to report on, so stay tuned.

Follow Up on Butter

Welcome readers. I wanted to post some follow up details on my experiments so far and say a bit more about the themes I will be writing more about. You'll notice that my headlines so far have been phrased as questions. This is not an homage to a popular quiz show -- they are questions because I don't know the answers. So with that in mind I wanted to revisit the results of my first experiment (Is Butter as Powerful as a Statin?).

Science is hard, and if you attempt it, you need to stay vigilant about not fooling yourself, because, as Richard Feynman has said, you're the easiest person to fool. So I'll be reviewing my initial results to see whether I've fooled myself. Of course when it comes to personal science, we should always be aware of this principle in reviewing work done by others. If someone has managed to fool himself (even for a moment), perhaps they might fool you too. I hope my readers will keep this in mind.

Commenter EricT highlighted the biggest weakness in my butter experiment.  I originally added the butter to my diet to see what sorts of subjective effects it might have (they were positive, but I did not track anything quantitative that I can present). I tracked my lipids at the time only in order to monitor whether they might move in an adverse direction. It looked like the Kerrygold butter caused beneficial changes while other brands did not. I therefore changed my hypothesis mid-stream, which is a substantial source of bias, effectively rendering my statistical analysis invalid (this particular weakness is not applicable to the second experiment on safe starches vs. HDL, though of course other weaknesses do apply). Meanwhile I am continuing the butter experiment and will present all additional data points in a couple of weeks so we can see whether the effect holds. In the mean time, by then I will have data from another VAP cholesterol test so I can have more confidence about what my CardioChek meter is actually measuring and how consistent it is. Stay tuned for that.  Meanwhile I have declared a "grain of salt" advisory on the butter post.

If the additional data points do not show a continuation of the effect seen previously, it would weigh strongly against the hypothesis that butter causes beneficial changes in lipids (though this is somewhat independent to the question of whether butter is good or bad from a cardiovascular perspective). Many alternative hypotheses could explain a negative outcome -- the effect could have been the result of the bias, a short-lived disruption of homeostasis, a systematic user error or environmental sensitivity with the CardioChek device, or an unknown and temporary cause coinciding in time with the applicable data points. Since I did not decide beforehand how long my experiment would last, the effect could also have been a statistical anomaly which only seemed "significant" because of the particular day on which I decided to compile my results (that is, you can't just wait until you get the result you want and choose that as the date on which to terminate your study).

In the mean time, I've been measuring another health marker that is related to gut health and the microbiome.  I am going to write about about that and then present some interesting and hopefully useful data over the next few weeks.

Is Butter As Powerful as a Statin?

Notice: A Grain of Salt Advisory is in effect for this post. See comments and this new post for details. Subsequent data collection has changed the conclusions presented below.

Butter is an interesting food. For those who have graduated from an un-scientific fear of fat, it would seem to encapsulate almost everything that is good about cow's milk, with only small amounts of the questionable stuff (lactose and milk proteins). What's not to like? Certainly some very sensitive people could respond negatively to the trace sugars and proteins in butter, but for most people it seems like it should qualify as a health food.

Health professionals are usually quick to warn us away from butter because it is high in artery-clogging-saturated-fat. The old story goes that butter is bad for you because saturated fat raises cholesterol, and elevated cholesterol causes heart disease. I can't do an n=1 experiment on the effects of butter on mortality but with a home cholesterol meter it is easy to find out whether the first part of the old story is true. Does butter actually raise blood cholesterol levels? Whether that has anything to do with heart disease is a story for another day (I happen to believe there may be a small relationship between cholesterol and heart disease for some people, but it's complicated).

In fact, eating half a stick of butter a day significantly lowered my cholesterol. It lowered it about as much as the reported effects of many statins (sorry, haven't tried the statins so you'll have to trust the clinical trials on those). Read on for the details, but first a few words about butter.

What color is it?

These days, most consumers expect butter to be white and margarine to be a pleasing yellow. Never mind the fact that margarine was originally colored yellow in order to make it look like healthy grass-fed butter. For years, many states had laws prohibiting the sale of artificially colored margarine. Housewives were sometimes sold a small packet of food coloring with each tub so they could trick their families into thinking they were eating something that was good for them.

Butter with a high vitamin content is yellow, not white. Unfortunately, artificially colored butter is also yellow. In fact, butter and cheese were the first foods the U.S. federal government allowed to be artificially colored. This gave butter producers a leg up in competing against margarine, where artificial colors were usually not allowed. For most foods, added colors need to be identified on the label and/or ingredients list. Butter is exempt from this requirement (see Section 101.22(k)(3) of Title 21 of the U.S. Code of Federal Regulations).  Therefore, do not judge American butter by its color.

The best butter is made from milk produced by cows that live outside and eat their natural diet, grass. The "organic" label can be applied to corn-fed cows raised in feedlots. Therefore, the term doesn't really tell you anything useful about the quality of butter. It is about as useful as calling farmed fish "organic." Personally I don't pay any attention to that label when it comes to butter and I look for butter that I am confident comes from cows that live outside and eat only grass.

Butter throughout History

Anthimus, an exiled Byzantine doctor writing in northern Gaul in the 6th century, recommended butter with honey to patients suffering from tuberculosis. This is interesting because, for many years prior to the introduction of antibiotics, cod liver oil (which, like grass fed butter, is rich in vitamin A) was the standard of care for tuberculosis treatment.

The dentist Weston A. Price found butter to be a staple food in many healthy populations around the world.

According to MS Iceland Dairies, which produces the Smjor brand of butter, the Icelandic people prized butter as an important and healthy food.

"People usually had considerable stores of butter; it was used extensively, and it was considered a source of strength during the harsh winter months when people needed to consume a lot of fat. The recommended portion was approximately 1700g a week per person."

For the Americans in the audience: 1700 grams of butter is over 3.7 pounds. Per week.

Butter seems to be especially valued in cold climates, perhaps because it could be stored prior to refrigeration without going too far rancid. For example, see Tibet and their famous rancid yak butter tea.

Cholesterol for Breakfast

As I mentioned above, I don't believe there is a strong relationship between blood cholesterol levels and heart disease risk. In addition, if there is a relationship between blood cholesterol levels and total mortality, it appears to be non-linear and probably U-shaped, with increased mortality when levels are too high or too low. That said, my cholesterol has been a bit higher than I'd like over the last 10 years or so, and I've tried on and off to see if there is a reasonable way to change it without doing something crazy like eating laxatives or plant hormones. Over the past year I've been monitoring my blood lipids from time to time with a CardioChek meter and paying attention to what causes the numbers to change. Most of the data for this experiment comes from the CardioChek machine, though some readings are lab tests ordered by my doctor.

Notwithstanding the absence of supporting evidence, the 2010 Dietary Guidelines for Americans recommend that humans consume no more than 300 mg of cholesterol per day. Now a few times in the past two years I have substantially varied my egg intake, and therefore my total dietary cholesterol. Although I don't have enough readings to get good statistics on these changes, my observation is consistent with the published scientific literature. There is no association between dietary cholesterol, per se, and my blood cholesterol. My cholesterol generally stays the same or perhaps drops a little when I eat more eggs (e.g. going from no egg consumption to 4 per day). There may be some subset of the population that is sensitive to dietary cholesterol, but I do not seem to fall into that category.

The Thousand Calorie Omelete

This story is not about eggs or dietary cholesterol. It is about what happened to me when I added a large amount of butter to my breakfast. In January I added half a stick of butter (about 57 grams) to my morning omelete. I first got this idea from Seth Roberts, who reportedly has been eating half a stick of butter per day for some time in order to increase his mental performance.  Seth believes butter has been good for his heart. Dave Asprey also recommends eating lots of butter for brain health, among other reasons. My omelete consists of four pastured eggs, half a stick of Kerrygold Irish butter, and three tablespoons of coconut oil. Thats 1,076 calories, 110 grams of fat (75 grams from saturated fat) and 865mg of cholesterol. My diet otherwise stayed the same, though I was usually eating smaller portions of everything else.

The effect this had on my blood cholesterol was significant enough to inspire me to finally start a blog. Of all the interventions I've tried over the years, this has been by far the most powerful and the first one to show up clearly after the first couple of data points.

Here are the results. On average: HDL is up 19%, non-HDL is down 25%. Both results are statistically significant with high confidence levels, despite relatively small sample sizes (p<.001 and .01 respectively). Here are some boxplots to make it more convincing. The plots show min, max, mean, and the 1st and 3rd quintiles.

Boxplots showing min, max, mean and quartiles.
Mean HDL (control, treatment, change): 65, 77, +19%.
Mean non-HDL (control, treatment, change): 196, 148, -25%

The following plots show my pre-butter trends for HDL and non-HDL in red, with the post-butter readings in blue (thanks Seth for the suggestion).  This suggests that the new readings do not reflect the continuation of a pre-existing trend.  I did not add trendlines for the post-butter readings because there are not enough datapoints for them to make sense.  Note that 5 of the 6 post-butter HDL readings are the highest ever recorded.  4 of the 6 non-HDL readings are the lowest ever recorded.

What's the Best Butter?

When I was growing up, I was quite a picky eater, and was very specific about the brands of butter that I would allow my parents to bring into the house.  Most brands tasted downright rancid.  Even still, I don't think I ever tasted good butter until I was well into my adult years.  The bad stuf is not worth eating, and I now have a bit of experimental evidence to back that up.


My butter of choice is Kerrygold from Ireland. While Kerrygold seems to be somewhat coy about saying "100% grass fed" in its marketing materials, it is pretty consistently cited as the best butter that is readily available around the U.S.  Trader Joe's almost always has the best prices in my vicinity.  During the course of this experiment, I tried two other types of butter.  One was Smjor, mentioned above.  The other was a "grass fed" butter from my local farmers' market.  The Smjor was delicious and very yellow, so it looked like a good pick.  The local butter was white and not especially appetizing, perhaps understandable for cows living in New York in the winter and necessarily given some kind of supplemental feed.  The cholesterol readings I was getting from the Smjor and local butter were all over the map and were not consistent with the numbers I got with the Kerrygold.  Therefore I did what any good scientist would have done and threw those data points away so I could present results only for thousand calorie omeletes made with Kerrygold.

Details of the Experiment

There are 6 measurements in the experimental (butter) group and 16 in the control (non-butter) group. Additional measurements taken within 1 week were not used. The butter group includes all measurements made when I had been eating at least 1/2 stick (about 56 grams) of Kerrygold butter per day for at least a week prior to measurement. Datapoints when I was consuming other brands of butter were not included. The first five measurements were VAP cholesterol tests ordered by my doctor.  Otherwise, I measured total cholesterol and HDL cholesterol in a single panel with a CardioChek PA. I did not measure LDL directly, and I did not calculate it because my fasting triglycerides are not measurable with my meter (<50). Besides, the LDL calculation formulas are nonsense at best when triglycerides are under 100. I use non-HDL as a rough estimate of the atherogenic potential of blood lipids (basically a crude proxy for apolipoprotein B).

The increase in HDL and decrease in non-HDL were both statistically significant as determined by ANOVA using R (p<.001 and .01 respectively). However, I should point out that, for a variety of reasons, these are not high quality statistics. First of all, I have no formal training in statistics. Given that some data points were taken fairly close together in time, there is likely some serial correlation between measurements. I also made no particular effort to control for other variables. Finally, these results apply to me. There may well be people who respond differently and for whom butter is unhealthy. As with anything, it is always advisable to test things for yourself. So take this with a grain of salt. Or half a stick of butter, if you prefer.