High cholesterol in anorexia nervosa

One of the (many) paradoxes of anorexia is that the excessive weight loss that accompanies the disorder often results in high cholesterol levels. This seems to go against what many doctors and researchers say about cholesterol: decreasing food and fat intake as well as increasing exercise should decrease cholesterol levels, not raise them.

It turns out that this high cholesterol (formally known as hypercholesterolemia) also happens to starving people, and is a well-known side effect of malnutrition. The question that remains, then, is why? Why this paradoxical effect?

Let me back up a bit and explain what cholesterol is and what it does. Cholesterol “is a lipidic, waxy alcohol found in the cell membranes and transported in the blood plasma of all animals. It is an essential component of mammalian cell membranes where it is required to establish proper membrane permeability and fluidity.” Cholesterol is hydrophobic, meaning it doesn’t dissolve in water or blood, so it is transported in the body by lipoproteins. Your total cholesterol count is a combination of triglycerides, low-density lipoproteins (LDLs, aka “bad” cholesterol) and high-density lipoproteins (HDLs, aka “good” cholesterol). Both LDLs and HDLs transport fats along with cholesterol. The lipid hypothesis holds that there is a causal link between high intake of saturated fats, hypercholesterolemia, and heart disease, promulgated by none other than Ancel Keys, he of the Minnesota Starvation Study.

So. What does this all mean?

Besides just having unusually high levels of total cholesterol, patients with anorexia were found to have unusually high levels of an enzyme called cholesterylester transfer protein (CETP), which swaps cholesterol and fat molecules between the different lipoproteins. The researchers speculated that low levels of thyroid hormones and low breakdown of existing cholesterol contributed to high cholesterol levels, and that “CETP activity increases cholesterol turnover as an adaptation to its low intake.” The highest levels were seen amongst AN patients who also binged and purged. In severely malnourished AN patients, however, cholesterol levels and CETP activities drop dramatically.

Other studies have suggested that starvation results in the increased synthesis of lipoproteins. It could also be that these lipoproteins are transporting fats in the body, which the body is relying on as fuel due to insufficient food intake. If the body is going to rely on fat as fuel, it needs some way to mobilize those fat molecules and get them to a location where they can be broken down effectively. This could perhaps explain the abnormal rise in cholesterol levels. As body fat is essentially depleted in the severely malnourished AN patients, the body may rely more and more on breaking down organ and muscle tissue, thus decreasing the need for abundant lipoproteins.

Regardless of the reasons for hypercholesterolemia during anorexia, it is NOT an indication that the sufferer needs a low-fat or low-cholesterol diet. With sufficient foot (and fat!) intake, cholesterol levels typically right themselves rather rapidly.

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10 Responses to “High cholesterol in anorexia nervosa”

  1. Wow, I never knew this before. My cholesterol was always on the high end of normal…nothing my dr. was concerned about, but I would think, “But I eat all low-fat, low-salt, low-everything.” I had no idea there was a link between higher cholesterol and anorexia. Thanks.

  2. Genetics also plays a role, too. I have high-ish cholesterol- nothing to freak out about, and I have abnormally high levels of HDLs. But high cholesterol also runs in my family. Literally the only two people I’m related to that aren’t on statins (okay, that are over 30) are my mom and brother. I would see what your cholesterol levels look like once you’ve been weight-restored for a few months.

  3. I know it’s a typo, but I love the phrase “with a sufficient foot (and fat) intake….”

  4. Ha! Well, I *put* my foot in my mouth quite a bit…I may as well eat the darn thing, eh?

  5. I have seen this before and asked for cholesterol testing but found both good and bad levels were low. So the “bad” cholesterol wasn’t bad, but the “good” cholesterol wasn’t good, and I was encouraged to eat omega-3 type foods/supplements. I had heard before that the high-cholesterol readings were related to liver function and breakdown of glycogen in lieu of available food intake. Are the cholesterol results independent and uncorrelated to body-fat composition? Re-feeding would be the same protocol for high-cholesterol patients as low- or normal-range? It’s supposed stabilize with nutrient and weight restoration? Will a low-cholesterol AN patient eventually find herself/himself with high readings if starved long enough, or is it believed to be a factor independent of “simple” starvation?

  6. I’ve often wondered why this occurs. Thank you for researching, and posting on this subject.

  7. Anon,

    Abnormal liver functions are common in AN (there was a recent paper on this in the International Journal of Eating Disorders), so it’s entirely possible that these are related. I don’t know how AN affects cholesterol levels long-term. That would be interesting to see.

  8. I vividly recall being told I had “borderline high” cholesterol when I was in the depths of my eating disorder. After which the doctor, who had full knowledge of my eating disorder (and the fact that I was significantly underweight), proceeded to tell me which foods to cut out of my diet. Seriously? It was a HUGE shock… I felt like someone had just told me I was obese and validated all of my worst fears. It wasn’t until about a year after that I learned that high cholesterol was associated with AN. After a couple of years of pretty solid recovery I’m in a completely normal range.

  9. most interesting topic that he was going to think that the anorexia produced a high cholesterol level due to digestion problem

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  1. A tale of two anorexia genetics studies | ED Bites - October 22, 2013

    […] Many sufferers of AN suffer from high cholesterol in the acute stage of illness, which has generally been attributed to the effects of starvation. These new results hint that it might not just be […]