Here are my cholesterol tests from the past couple of years along with my most recent results. My initial results from 2010 when I was following the standard american diet actually look remarkably ideal, despite the diet, however I was running almost 3 miles a day during this period AND I was carrying around more weight and a greater body fat percentage. So while my blood work looked ideal, my outside appearance didn’t really reflect it… and I was exhausted from all the running I was doing.
While we saw in part 1, according to the scientific literature, on a ketogenic diet cholesterol can either increase, decrease or stay the same, no clear explanations were presented, so of course I had to do some more searching on my own.
It’s interesting to see that my numbers got worse as I continued to follow the Slow Carb Diet, all the while my body fat percentage and overall weight were coming down. I dropped multiple pants sizes and had to buy a whole new wardrobe since my clothes were all becoming too loose. I remember having some basketball shorts that I’d kept around since college that were always kind of snug and being confused as to why they kept slipping off while I was playing basketball. It took me a while to realize that this was because I had lost so much body fat.
With this pattern in mind, I was truly fascinated to see what would happen to my cholesterol numbers while experimenting with nutritional ketosis. If you’ve been following me for a while, you know that while my weight has been relatively unchanged since beginning, my overall body circumference has been decreasing which indicates that I’m losing more body fat. This was my primary reason for starting this way of eating, so seeing those numbers come down meant that I was accomplishing the goal I initially set out for… which is pretty awesome. On the other hand my cholesterol look even worse.
On a side note, during this last test I also got an NMR lipid profile to measure my LDL particle count which has been shown to more directly correlate with risk compared to a simple LDL-C. I wanted to do this at least once because there are cases where the LDL-P and LDL-C numbers can be discordant which can cause misleading results… unfortunately in my case the LDL-C and LDL-P were concordant, and both extremely high!
Now I know from searching around on the net that this is not an isolated phenomenon. For one thing, Jimmy Moore is in the same boat… despite losing almost 80 lbs, he’s observed a continued rise in his cholesterol numbers as well. People who’ve been eating paleo and low carb (other examples here and here) have also observed this.
Now the question is why? Why does cholesterol increase despite increased fat and overall weight loss?
Possible explanations that I’ve come across are:
- Increased consumption of saturated fats in some people can lead to an increased production in saturated fats by their livers for some unknown reason. Dr. Dayspring, a lipidologist, has observed this phenomenon in 20-30% of his patients.
- A possible explanation put forth by Paul Jaminet, author of the Perfect Health Diet, is that this might be due to deficiency in certain micronutrients such as choline and copper.
- I don’t think choline deficiency is a factor in my case since eggs are a regular staple of my diet (choline is found in egg yolks).
- Some people think that this is a natural response to weight loss in a low carb setting since your body is mobilizing more fatty acids for energy. Remember, the whole purpose of nutritional ketosis is to allow your body to burn fat for fuel rather than carbohydrates, so there will be more fat floating around moving back and forth to be metabolized for fuel.
- I’m not too convinced of this because it suggests EVERYONE in ketosis should have these elevated cholesterol numbers, except that it’s only found in a small amount of people (20-30% according to Dr. Dayspring). There are many low carbbers out there with phenomenal cholesterol levels.
- In my case, I’ve only lost a few pounds during my ketosis experiment, which doesn’t seem like it should be enough to warrant the high level of cholesterol that I’m seeing.
- Another explanation, best articulated in this post by Paul Jaminet, is that a chronic low carb state can actually lead to hypothyroidism manifested by a low T3 (the potent form of thyroid hormone), which then causes a decrease in LDL receptors (the guys that pick out LDL from your blood stream), which causes a higher serum cholesterol level.
- In the post above, a commenter named Gregory Barton, noticed the same phenomenon of having rising cholesterol numbers despite losing weight while on low carb. He checked is cholesterol weekly for 15 weeks and noticed that the longer he went low carb, the higher his cholesterol went. The once he began supplementation with thyroid hormone, his cholesterol numbers dropped precipitously. The certainly lends credence to this theory… even though it was only an n=1.
- This explanation also helped me to remember that according to Tim Ferriss, one of the benefits of having the cheat day on the Slow Carb Diet was to prevent your body from getting to the point where it is so carb deficient that it tries to slow down its metabolism by becoming hypothyroid.
So at this point we’re left with 4 possible explanations as to why this happens… and to further explore these explanations I have to embark on a few more n=1 experiments.
While I won’t be checking my cholesterol weekly like in Gregory Barton’s experiment, I think an interval of 2-3 weeks would be reasonable.
- There’s nothing I can really do to test explanation 3, so I’m just going to leave that out for now.
- I’ll first check baseline thyroid levels.
- Then I’ll test explanation 1 by cutting back on my fat intake. I will try to do this while staying within the parameters of nutritional ketosis since I still intend to continue this diet a while longer.
- If I don’t notice any significant change with my cholesterol levels, I’ll then go on to test explanation 2 by taking some copper supplements and continuing to eat eggs.
- If still no change, then I’ll test explanation 4 by first taking iodine supplements to help with my thyroid hormone levels
- And if that doesn’t lead to a change in my thyroid or cholesterol levels, I’ll up my carb intake, stopping my nutritional ketosis experiment, and then recheck my cholesterol.
Stay tuned for part 3…
*A final thing I wanted to add is that despite having a high cholesterol, we still don’t know whether this is a even a bad thing in people who eat low carb. Cholesterol only causes problems once it goes INTO your blood vessel wall as a result of inflammation. If you have a high cholesterol, but all of it stays in your blood WITHOUT going into your blood vessel wall, then theoretically your risk isn’t higher than someone with normal cholesterol.
In people who eat a high carb diet, they are exposed to more inflammation, and if they also have high cholesterol, then the inflammation will cause the cholesterol to go INTO the blood vessel wall causing them to have a worsened cardiovascular risk. In people who are low carb, with low levels of inflammation (both Jimmy and I have low inflammatory markers), it is unclear if having high serum cholesterols actually equates to a worsened cardiovascular risk.