In order to protect sensitized workers, psyllium has an extremely low occupational exposure limit of 150 ng/m3. Mechanism of action
The soluble fiber in psyllium is the polysaccharide heteroxylan, a hemicellulose.Psyllium is produced mainly for its mucilage content. The term mucilage describes a group of clear, colorless, gelling agents derived from plants. The mucilage obtained from psyllium comes from the seed coat. Mucilage is obtained by mechanical milling (i.e. grinding) of the outer layer of the seed. Mucilage yield amounts to about 25% (by weight) of the total seed yield. Plantago-seed mucilage is often referred to as husk, or psyllium husk. The milled seed mucilage is a white fibrous material that is hydrophilic, meaning that its molecular structure causes it to attract and bind to water. Upon absorbing water, the clear, colorless, mucilaginous gel that forms increases in volume by tenfold or more. Cultivation
The genus Plantago contains over 200 species. P. ovata and P. psyllium are produced commercially in several European countries, Russia and surrounding countries, and India. Plantago seed, known commercially as black, French, or Spanish psyllium, is obtained from P. psyllium, also known as P. arenaria. Seed produced from P. ovata is known in trading circles as white or blonde psyllium, Indian plantago, or isabgol. Isabgol is the common name in India for P. ovata. it is known as Aspaghol in Pakistan, coming from the Persian asp and gul, meaning "horse flower", which is descriptive of the shape of the seed. India dominates the world market in the production and export of psyllium.
The purely mechanical action of psyllium mucilage is to absorb excess water while stimulating normal bowel elimination. Although its main use has been as a laxative, it is more accurately regarded as a dietary fiber and as such can help reduce the symptoms of both constipation and mild diarrhea. The laxative properties of psyllium are attributed to the fiber: it absorbs water and subsequently softens the stool. It increases flatulence (gas) to some degree. High blood cholesterol
In 1998, the U.S. Food and Drug Administration approved a health claim on food labels for dietary psyllium as a soluble fiber – if consumed regularly – that would reduce the risk of heart disease by lowering blood cholesterol. Clinical research demonstrated that seven grams or more per day of soluble fiber from psyllium seed husk would sufficiently lower total cholesterol and low density lipoprotein cholesterol in people with hypercholesterolemia, two accepted biomarkers for risk of coronary heart disease. The findings were later confirmed in a meta-analysis that incorporated more evidence. To be eligible for the FDA-allowed health claim, one serving of a manufactured food or dietary supplement must contain at least 1.7 g of psyllium as soluble fiber. Whole oats, barley and foods containing beta-glucan soluble fiber were included as eligible sources for the label claim.