Psyllium Fiber and Cholesterol

Overview

High cholesterol is a well-known risk factor for heart disease. Total cholesterol is a measure of both low-density lipoproteins, or bad cholesterol, and high-density lipoproteins, or good cholesterol. Total cholesterol has two primary sources. Contrary to popular belief, diet contributes a mere 25 percent of cholesterol the total cholesterol pool. Alternatively, 75 percent of the total cholesterol is produced in the body, specifically in the liver, according to the American Heart Association. Dietary approaches, such as the addition of psyllium fiber, appear to significantly lower cholesterol by interacting with the production, metabolism and excretion of the entire cholesterol pool.

Cholesterol Metabolism

In 1999, the PPAR Research journal published the article, “Regulation of Bile Acid and Cholesterol Metabolism by PPARs.” This article explains that bile acids are the primary pathway for cholesterol excretion. Bile acid production uses the liver enzyme cholesterol 7 alpha-hydroxylase, which works to convert cholesterol into bile acids. After being produced in the liver, bile acids continue onto the intestines in the form of bile-the substance that facilitates fat absorption. Bile is stored in the gallbladder. After reaching the intestines and assisting with the absorption of ingested fat, 95 percent of bile acids are reabsorbed. Reabsorption ensures an adequate supply at the next meal. Five percent of the bile acids are lost in the feces. However, the production of new cholesterol within the liver, compensates for this loss.

Fiber-Cholesterol Connection

According to the 1991 Journal of Nutrition article by Bahrah H. Arjmandi, blood cholesterol levels reportedly decreased with the ingestion of water-soluble fibers. In this study pectin, an apple fiber, was indicated as the most effective soluble fiber in lowering blood cholesterol. It was suggested that a 5 percent pectin-supplemented diet in rats reduces the absorption of dietary cholesterol, leading to its increased excretion in stool. In a 1994 study published in the Journal of Nutrition, Hugh Matheson explains another mechanism by which soluble fiber lowers cholesterol. In this study, Matheson notes that psyllium and pectin fibers increase the activity of the bile acid producing enzyme, 7-alpha hydroxylase. Bile acids, which under normal conditions only account for a 5 percent removal of cholesterol from the body, were increased by almost twofold on the pectin or psyllium-containing diet.

What is Psyllium Fiber

As part of a heart-healthy diet, the AHA suggests the consumption of between 25 and 30g of total fiber per day. Total fiber includes both insoluble fiber and water-soluble, or “soluble” fiber. The 1997 Journal of Nutrition article written by Beth H. Olsen, notes that psyllium is a soluble fiber. It is derived from the seed husk of the Plantago ovata plant. It forms mucilage when combined with water, and it is commercially known as the bulk-forming laxative Metamucil.

Dietary Psyllium

A meta-analysis of psyllium-enriched cereals generated a positive outcome in lowering cholesterol in human studies. The analysis, published by Beth H. Olson, reviewed 12 studies encompassing over 400 adults in four countries. The conclusions drawn from this analysis state that, at a dose of approximately 3g of soluble fiber per day, psyllium-enriched cereals lowered total and LDL cholesterol.

Adverse Reactions

Common complaints among psyllium participants in the meta-analysis in the February 2000 American Journal of Clinical Nutrition were symptoms involving the digestive tract, including gas, abdominal pain, diarrhea, constipation, dyspepsia or nausea. However, similar symptoms were noted in the placebo group. Even in the elderly, psyllium was well-tolerated, and no changes related to vitamin or mineral status were observed in any of the psyllium-treated groups.

About this Author

Dr. Shavon Jackson-Michel is an expert in the field of health and wellness and has been writing for LIVESTRONG.COM since 2009. She is a university-level professor and a licensed naturopathic physician providing individualized consultations on natural and holistic approaches to chronic disease at her Bloomfield, NJ office. Dr. Jackson-Michel is a doctoral graduate of the University of Bridgeport College of Naturopathic Medicine.