Psyllium husk is pretty amazing stuff, mostly because of its unique dual-action potential to benefit both GI health and cardiometabolic health via its cholesterol-lowering effect. Seems almost miraculous in some ways, i.e. as a natural laxative and as a “natural statin”. Surely, such a snake oil claim should raise eyebrows in academia, right? Yet, upon further investigation, there do appear to be numerous factors worthy of serious consideration. Before I delve too deeply into the science, I would first like to discuss psyllium anecdotally. Indeed, psyllium husk, when I was taking it regularly a few years ago, did keep me very regular, but it also made me feel a bit bloated. My wife in fact complained that the water retention side effect made her “look fat”. An interesting German observational study from 2008 examined the issue of compliance in regards to fiber-containing supplements in general and psyllium husks specifically. As a nutritionist, it may indeed present as a “hard sell” if I have to tell my clients that I have a gentle natural solution for their constipation, but it may also make them feel like a hot air balloon and clear out any room with explosive flatulence, especially if the psyllium is ingested in tandem with a high-protein diet from animal sources. Legumes of course receive honorable mention in this department, as always!
Psyllium is used clinically as a bulk laxative, an agent with laxative effects that are secondary to increasing fecal size, a much milder laxative relative to diuretics such as caffeine. The bulk occurs due to water and gas absorption in the small intestine and the colon, giving chyme (made from digested food) more size and softness. This bulk is retained in the colon despite microflora, since psyllium is generally poorly fermented. Although psyllium has been proven to increase fecal size and moisture, the most common characteristics of stool following supplementation with psyllium tend to be generally soft and easily passable, hence an indirect cure for transient and long-term constipation, but cannot be accurately equated with diarrhea by any stretch.
Beyond the fecal benefits (yes, I said fecal benefits!), psyllium appears to also reduce cholesterol and LDL in individuals with high total cholesterol, secondary to the gel forming properties leeching bile acids and cholesterol that is used to replace hepatic bile acids. There is also a slight reduction in the most dangerous form of LDL cholesterol, i.e. VLDL, which is most strongly associated with arteriosclerosis. However, in all fairness, this property is associated with all dietary fibers, not just psyllium. Additionally, there appear to be some glucose-reducing effects attributable to psyllium supplementation as well, which may benefit Type II diabetics. This effect is not overly potent, but does appear to be reliable as long as psyllium is ingested regularly. Cessation of psyllium usage results in quick loss of glucose reduction, as in the case of all sources of soluble fiber. In a future post, I will discuss the larger topic of optimizing the ratio of soluble/insoluble fiber to achieve the greatest health benefits and least side effects.
As for the actual numbers, Psyllium husk contains about 5 grams of soluble fiber per 1 tablespoon serving. This provides 20 percent of the recommended daily value of fiber relative to a 2000 calorie-per-day diet. As my uncle in his 90s once reminded me, the older we get the more we start to appreciate the guilty pleasure of a healthy prodigious bowel movement every morning! But enough poop talk for now. Have a healthy week!