Psyllium, also known as Plantago ovata and Indian plantago, is popularly used in traditional Indian medicine for prevention of skin irritations, hemorrhoids, constipation and diarrhea.(1) Its use and consumption in Europe and the United States of America has increased in recent years.(1) It has been widely investigated for its applications in pharmaceutical and food industries, as well as its potential health benefits, and this article sheds some light onto what those are.
What is psyllium?
Also known as Isabgol, meaning “horse ear” in Indian, thus named for the seed’s shape, psyllium belongs to the Plantago genus, which comprises of over 250 species worldwide.(1) Its seeds have been used for centuries in indigenous medicine and are produced by Pakistan, several European countries and India, which dominates its production and exportation.(1) The main importers are the USA, Germany and the United Kingdom.(2)
It is a short-stemmed annual herb that grows up to 45cm in height, has long, narrow leaves, and is coated with fine, soft hairs.(1) It has flower spikes with white flowers, and is ripened when the flower spikes turn reddish brown.(1) The fruit is a small, approximately 8mm long capsule that opens at maturity and contains hard, boat-shaped, rosy-white or rosy-brown seeds.(1) The seed husk is an odorless, tasteless, translucent, rosy-white mucilaginous membrane, which represents about 30% of the seed’s weight.(1)
Psyllium and its health benefits
The first study about psyllium was done in 1988 and the interest in the plant has only increased since then, especially in recent years.(2)
Psyllium is one of the most fiber-rich ingredients among natural products(2) and its husk consists of 85% water-soluble fiber,(1) along with other nutrients. The seeds and husks are rich in bioactive compounds,(1) meaning the compounds influence living organisms. The most abundant are fatty acids (such as linoleic, oleic and palmitic acid), amino acids, polyphenols and flavonoids.(1)
Psyllium is a hydrocolloid - meaning it solidifies liquid into gel.(2) It is considered as such due to its functional properties, such as solubility and viscosity, the latter being responsible for its nutritional benefits and its high water absorption capacity.(2) It is common to use the word “gum” to name some hydrocolloids, the term being related to their capacity to disperse in water and generate a more viscous solution.(2)
As viscous fibers can alter the viscosity of the food being digested in your gastrointestinal tract and thus inhibit the absorption of nutrients - particularly glucose and cholesterol, psyllium has positive effects on constipation, diarrhea, irritable bowel syndrome, inflammatory bowel disease and colon cancer.(2) It can reduce the glycemic index in both diabetic and non-diabetic patients, decrease total and LDL cholesterol and the feelings of hunger, which all decrease the risk of cardiovascular disease.(2)
Psyllium is one of the most widely used fiber supplements, as it is reasonably inexpensive and better tolerated than other fiber supplements.(2) It is also worth mentioning, that psyllium has antioxidant properties.(1)
As fiber is an important part of a healthy and balanced diet, psyllium is often mentioned in connection to weight loss. However, Darooghegi et al. (4) have found that the studies done on humans have produced inconsistent and controversial results. In their meta-analysis, they took a closer look at twenty-two studies written between 1983 and 2018.(4) What they established was that no significant effect of psyllium on body weight, body mass index and waist circumference in adults was found.(4) However, they maintain that further, large scale studies with different doses of psyllium and longer periods of intervention are required to confirm their findings.(4)
Use of psyllium in food products
Studies have shown that psyllium is a promising ingredient to be incorporated into food products, due to its functional properties, coupled with its gel-forming ability.(1)
When adding psyllium to biscuits, at concentrations 3-9%, the biscuits darkened, fiber and ash contents increased and protein content decreased.(1) Concentrations higher than 10% caused some technological restrictions, as it was not possible to shape the biscuits, due to the high fiber content.(1) The addition of psyllium may also be an interesting alternative in gluten-free bread preparation, as it positively affects the dough’s texture, increases its fiber content and decreases its glycemic index, but an adequate amount of water must be added in order to prevent too much hardening.(1)
Psyllium has also been used in products such as yogurts, sausages, jams, pizzas, cakes and more, with varying results.(1)
Some studies show that adding psyllium to food products may negatively affect their physical properties, such as texture and color, as well as sensory acceptance.(1) However, it is possible to produce higher quality food products by adjusting psyllium ratios or using additives to combat its negative effects.(1) Also, many of psyllium’s health benefits depend on its ability to form gel, thus it is necessary to consider whether the food’s production process can diminish its efficiency.(2)
Conclusion
More studies are needed to determine how to incorporate psyllium into food products without having a negative impact on them, as well as how it interacts with other food components, such as sugars, starch, fibers and proteins.(2) More studies also need to be carried out to prove some of its suggested health benefits. Still, the nutritional advantages and health benefits that have already been proven, speak for themselves, and what they are telling us is that when faced with a choice between food products, we should steer towards buying the one with psyllium written amongst its ingredients.
References:
- Franco EAN, Sanches-Silva A, Ribeiro-Santos R, de Melo NR. Psyllium (Plantago ovata Forsk): From evidence of health benefits to its food application. Trends in Food Science & Technology. 2020; 96: 166-175.
- Belorio M, Gómez M. Psyllium: a useful functional ingredient in food systems. Critical Reviews in Food Science and Nutrition. 2020. Available from: doi: 10.1080/10408398.2020.1822276.
- Raymundo A, Fradinho PP, Nunes MC. Effect of Psyllium fibre content on the textural and rheological characteristics of biscuit and biscuit dough. Bioactive Carbohydrates and Dietary Fibre. 2014; 3(2): 96–105. Available from: https://doi.org/10.1016/j.bcdf.2014.03.001.
- Darooghegi Mofrad M, Mozaffari H, Mousavi SM, Sheikhi A, Milajerdi A. The effects of psyllium supplementation on body weight, body mass index and waist circumference in adults: A systematic review and dose-response meta-analysis of randomized controlled trials. Critical reviews in food science and nutrition. 2020; 60(5): 859-872.
