I was out to breakfast with a friend today and he's started on the "Karen Hurd diet." I've heard of this dietitian before in my circles and several follow her like a savior. In fact, when my wife was pregnant with our first, she was told that Karen Hurd had a "cure" for morning sickness: soluble fiber.

This morning I found out that Karen also has a cure for high cholesterol (drum roll): soluble fiber.

I've looked into this a bit before, particularly when my wife was nauseous. She brought home a writeup of Karen Hurd's theory and I didn't buy it (this was about 3.5 years ago).

Bile is a digestive enzyme designed to break down the fatty acids that we eat. When we have no fatty acids in our duodenum (the first part of the small intestine and what most people commonly call “the stomach”), there is nothing to digest but YOU! This causes us to feel nauseous.

It seems to make sense that if the bile is meant to digest fatty acids, all we need to do is give the bile the fatty acids it wants to digest. Then the bile will not bother our intestinal lining making us feel nauseous. But, when we eat foods with fats in them, it actually causes a further release of bile. Now we have the original bile making us feel queasy PLUS a new onslaught of this same nauseous-causing substance.

Soluble fiber and bile (or any fatty acid) have a great affinity toward one another. In fact, they will bind so tightly together that they cannot be parted. As no fiber (soluble or insoluble) can cross the intestinal barrier, all the bile that has been bound together with the soluble fiber will exit the body through a bowel movement. That means the bile will not recycle. That means the bile will not grow nasty with accumulating debris. That means you will feel less nauseous.

The story is quite similar in her writeup on high cholesterol:

Our Creator designed our bodies to use cholesterol in the making of bile. Bile is a digestive enzyme that aids in the breaking down of fats in the intestinal tract. If a person can produce a regular supply of bile, then cholesterol levels will drop as this raw material is converted into a useful digestive enzyme.

Soluble fiber binds tightly with bile in the intestinal tract, in fact, so tightly that the bile cannot be reabsorbed through the intestinal tract and return to the liver...Over the course of time, levels will fall to the point of a total cholesterol of 150 or below.

...it is this author’s hypothesis that the liver releases an enzyme at this point of 150 and below that literally melts the hardened plaque off the interior of the blood vessel walls, so that the oxidized cholesterol is then available in the bloodstream for the liver to utilize in the making of bile.

Is there any evidence to support these claims about the interaction between bile, cholesterol, hormones, and soluble fiber? I became suspicious when I read the writeup on morning sickness many years ago, but to hear such a similar hypothesis (bile, etc.) being proposed re. high cholesterol really struck me as odd.

Oddly enough, check out THIS google search for the word "bile" on her site. Quite a few of her writeups mention it. I've never heard of bile being so destructive or such an integral component to various health issues before hearing about this dietitian and want to investigate.


  • Karen Hurd site (LINK)
  • Writeup on morning sickness (LINK)
  • Writeup on cholesterol (LINK)
  • "I've never heard of bile being so destructive or such an integral component to various health issues before hearing about this dietitian and want to investigate." It's vaguely reminiscent in the old theories of the balance of bodily humors (en.wikipedia.org/wiki/Humorism). She doesn't advocate for leeching, does she? – Beofett Jun 21 '11 at 16:32
  • @Beofett: Haha! Not that I know of. Mostly eating tons of beans, at least from those I know on her diet. It just seems like she's completely speculating about the various mechanisms, which would be on par with balancing the humors... – Hendy Jun 21 '11 at 16:45
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    Interesting. I see from her site that she is a linguist who taught herself nutrition, and then later took a correspondence course to get her degree in Nutrition from the American Academy of Nutrition (now called the Huntington College of Health Sciences), which is listed as "accredited, but not recommended" on QuackWatch.org (quackwatch.org/04ConsumerEducation/nonrecorg.html), and which was denied probationary authorization to operate in the state of CO by the Colorado Commission on Higher Education (highered.colorado.gov/CCHE/Meetings/2009/sep/sep09iiia.pdf). – Beofett Jun 21 '11 at 17:04
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    any "miracle" isn't... If it worked she'd have been able to show scientific data to prove it. – jwenting Feb 21 '12 at 6:24
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    "Bile is a digestive enzyme". I stopped there, this sentence only tells me the writer does not have a clue about physiology. Actually, I tried to read the second bit and, again, I stopped at "Our Creator designed our bodies to use cholesterol in the making of bile". My opinion of the writer lowered even more. – nico Mar 11 '12 at 11:49

Holy cow! Apparently, soluble fiber has been shown to reduce cholesterol and reduce risk of various heart issues!

  • Fernandez, "Soluble fiber and nondigestible carbohydrate effects on plasma lipids and cardiovascular risk," 2001 (SOURCE):

Several large-scale cohort studies have documented that dietary fiber lowers the risk for coronary heart disease. In addition, there is substantial evidence from randomized controlled clinical trials that a mean reduction of 9% in LDL-cholesterol can be achieved by intake of different sources of soluble fiber.

  • Bell et al., "Cholesterol-lowering effects of soluble-fiber cereals as part of a prudent diet for patients with mild to moderate hypercholesterolemia," 1990 (SOURCE):

Soluble-fiber breakfast cereals were examined for their cholesterol- lowering ability in 58 male patients with mild to moderate hypercholesterolemia in a randomized, double-blind, placebo-controlled study...During the cereal-plus-diet phase, total and LDL cholesterol values of the pectin-enriched cereal group dropped an additional 2.1% (P = 0.243) and 3.9% (P = 0.16), respectively, and they dropped 5.9% (P = 0.005) and 5.7% (P = 0.034), respectively, in the psyllium-enriched cereal group. During the cereal-plus-diet phase, no significant effects on HDL cholesterol, triglyceride, or body weight were found within or between any cereal groups. These results support use of soluble-fiber cereals as an effective and well-tolerated part of a prudent diet in the treatment of mild to moderate hypercholesterolemia.

  • Jenkens et al., "Combined effect of vegetable protein (soy) and soluble fiber added to a standard cholesterol-lowering diet," 1999 (SOURCE):

Compared with the low-fat control diet, the test diet [vegetable protein and soluble fiber) decreased total cholesterol, low-density lipoprotein (LDL) cholesterol, apolipoprotein B, and the ratios of LDL to high-density lipoprotein (HDL) cholesterol and apolipoprotein B to A-I. A combination of vegetable protein and soluble fiber significantly improved the lipid-lowering effect of a low-saturated-fat diet. The results support expanding the current dietary advice to include increased vegetable protein and soluble fiber intake so that the gap in effectiveness between a good diet and drug therapy is reduced.

I had no idea. I guess that the recommendations about soluble fiber and cholesterol are true, after all.

Even more, I found these:

  • Jenkins, "Effect on blood lipids of very high intakes of fiber in diets low in saturated fat and cholesterol," 1993 (SOURCE):

The loss of fecal bile acids was 83 +/- 14 percent greater during the soluble-fiber period than during the insoluble-fiber period (P < 0.001) and was related to the differences in total and LDL cholesterol and apolipoprotein B levels...

Incredible! Bile really does seem to have had an increase in excretion rates when soluble fiber was consumed. Whether this is due to Hurd's binding theory or not, I'm not sure -- but at the least, bile is being expelled at a greater rate.

  • Lia et al., "Oat beta-glucan increases bile acid excretion and a fiber-rich barley fraction increases cholesterol excretion in ileostomy subjects," 1995 (SOURCE):

The 24-h excretion of bile acids was 53% higher in the [oat bran] diet period than in the [oat bran with beta beta-glucanase] diet period and also was significantly higher than in the [barley] and [wheat] diet periods (P < 0.05). Median (range) bile acid excretion was 851, and 606 mg/d in the [oat bran], [oat bran with beta-glucanase], [barley], and [wheat] diet periods, respectively. The excretion of cholesterol was significantly higher in the [barley] diet period than in the [oat bran with beta-glucanase] and [wheat] diet periods (P < 0.05), but the mechanism behind this effect of barley fiber is unknown. In oat bran, however, beta-glucan mediates an increase in bile acid excretion, which most probably explains the effect of oat fiber in lowering serum lipids.

So, again, bile acid increased with test diets, but it appears that the mechanism is unknown.

I still have no evidence for soluble fiber binding with Human chorionic gonadotropin (hCG) and/or bile to reduce morning sickness. It's also undetermined exactly how soluble fiber is dealing with cholesterol or bile, at least from my survey. So... it's unclear as to whether Hurd is just speculating or has any basis for her claims.

At the very least, I can say that my research surprised me a great deal (due to finding the positive connection with soluble fiber, cholesterol decreases, and increase in bile expulsion rates), but I'm still skeptical about mechanisms and morning sickness. This is all I've found for now.

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