It is great to be back in sunny Singapore after a fruitful trip to Breckenridge!
Today, I would like to share a little about this wonder fiber that nature has provided for us, especially for those who need to control their high cholesterol. Our laboratory has independently conducted experiments to test the cholesterol-lowering effects of psyllium and I am therefore very convinced of its effects (read
our paper if you want the details).
Benefits of Dietary Fiber
It has been known for a long time that a high intake of fiber in our daily diet is good for health. A high-fibre diet is associated with reduced risks of heart disease, colon cancer and obesity [1]. The health benefits of consuming large amount of dietary fiber were first suggested more than 30 years ago [2]. Since then, evidences of the link between dietary fiber and heart disease have accumulated from population studies [3-6] and clinical trials [7-8]. There are two main types of dietary fiber - soluble and insoluble. Insoluble fiber has not been shown to exhibit a consistent cholesterol-lowering effect. In contrast, consuming a high-fiber diet containing viscous soluble fiber is known to significantly lower the total and low-density lipoprotein (LDL) cholesterol levels, which is the bad cholesterols in the blood [9-11]. What is Psyllium? Psyllium is pronounced "sil-ee-um" (the "P" is silent). It is derived from Plantago ovato, or plantain plants, and is grown mainly in India, Spain and France. The outer part of the psyllium seed, called the husk, is the portion that has the cholesterol-lowering property. Psyllium husk is easily available in health food stores. It can be consumed by adding into fruit juice or any drink, or added into breads, cereals, and pasta. Some cereal products are enriched with psyllium.
Psyllium Husk
What you are more likely to see when you buy a packet/bottle of psyllium husk
Cholesterol-lowering properties of psyllium
Let us try to understand how the lowering of the cholesterol can be achieved. Very simply put, this can be brought about by either causing the body to get rid of more cholesterol or to make less of it. It appears that psyllium works through the former, that is, it helps the body to get rid of more cholesterol through the formation of bile acid [12], which is excreted out along with the stool. This process accounts for 40–50% of the daily elimination of cholesterol [13,14]. The liver is the main site of bile acid formation.
Among the various forms of viscous soluble fibers, psyllium husk appears to be the most effective in lowering cholesterol levels [15,16] and has the least adverse side effects.17 The effect of psyllium husks on fasting plasma cholesterol has been evaluated in individuals with high-cholesterol, obesity, or diabetes [18-19]. In general, these studies show that psyllium husk consumption could bring about a 5% reduction in total cholesterol and 7–8% reduction in LDL cholesterol, which were sustainable in the long term [20, 21].
How much of psyllium should I consume to lower my cholesterol and for how long?
Clinical trials have shown that typically, about 10g per day (over 2-3 doses) for about 2 months is sufficient to achieve a cholesterol-lowering effect.
Reference List
1. D. Kritchevsky and C. Bonifield, Dietary fiber in health and disease, Plenum Press, New York (1997).
2. D.P. Burkitt and H.S. Trowell, Refined carbohydrate foods and disease: some implications of dietary fibre, Academic Press, London (1975).
3. K.T. Khaw and E. Barrett-Connor, Dietary fiber and reduced ischemic heart disease mortality rates in men and women: a 12-year prospective study, Am J Epidemiol 126 (1987), pp. 1093–1102.
4. C.G. Humble, A.M. Malarcher and H.A. Tyroler, Dietary fiber and coronary heart disease in middle-aged hypercholesterolemic men, Am J Prev Med 9 (1993), pp. 197–202.
5. D. Kromhout, E.B. Bosschieter and C. de Lezenne Coulander, Dietary fibre and 10-year mortality from coronary heart disease, cancer, and all causes. The Zutphen study, Lancet 2 (1982), pp. 518–522.
6. A. Wolk, J.E. Manson, M.J. Stampfer, G.A. Colditz, F.B. Hu and F.E. Speizer et al., Long-term intake of dietary fiber and decreased risk of coronary heart disease among women, JAMA 281 (1999), pp. 1998–2004.
7. I. Hjermann, K. Velve Byre, I. Holme and P. Leren, Effect of diet and smoking intervention on the incidence of coronary heart disease Report from the Oslo Study Group of a randomised trial in healthy men, Lancet 2 (1981), pp. 1303–1310.
8. A.C. Arntzenius, D. Kromhout, J.D. Barth, A.V. Bruschke and B. Buis et al., Diet, lipoproteins, and the progression of coronary atherosclerosis The Leiden Intervention Trial, N Engl J Med 312 (1985), pp. 805–811. M.L. Burr, A.M. Fehily, J.F. Gilbert, S. Rogers, R.M. Holliday and P.M. Sweetnam et al., Effects of changes in fat, fish, and fibre intakes on death and myocardial reinfarction: Diet And Reinfarction Trial (DART), Lancet 2 (1989), pp. 757–761.
9. D.J. Jenkins, T.M. Wolever, A.R. Leeds, M.A. Gassull, P. Haisman and J. Dilawari et al., Dietary fibres, fibre analogues, and glucose tolerance: importance of viscosity, Br Med J 1 (1978), pp. 1392–1394.
10. S.R. Glore, D. Van Treeck, A.W. Knehans and M. Guild, Soluble fiber and serum lipids: a literature review, J Am Diet Assoc 94 (1994), pp. 425–436.
11. D.J. Jenkins, C.W. Kendall, M. Axelsen, L.S. Augustin and V. Vuksan, Viscous and nonviscous fibres, nonabsorbable and low glycaemic index carbohydrates, blood lipids and coronary heart disease, Curr Opin Lipidol 11 (2000), pp. 49–56.
12. C.C. Schwartz, M. Berman, Z.R. Vlahcevic and L. Swell, Multicompartmental analysis of cholesterol metabolism in man, J Clin Invest 70 (1982), pp. 863–876.
13. D.M. Heuman, Z.R. Vlahcevic, M.L. Bailey and P.B. Hylemon, Regulation of bile acid synthesis. 11 Effect of bile acid feeding on enzymes regulating hepatic cholesterol and bile acid synthesis in the rat, Hepatology 8 (1988), pp. 892–897.
14. Z.R. Vlahcevic, D.M. Heuman and P.B. Hylemon, Regulation of bile acid synthesis, Hepatology 13 (1991), pp. 590–600.
15. P. Bell, K.J. Hectorn, H. Reynolds and D.B. Hunninghake, Cholesterol lowering effects of soluble-fiber cereals as part of a prudent diet for patients with mild to moderate hypercholesterolemia, Am J Clin Nutr 52 (1990), pp. 1020–1026.
16. J.W. Anderson, A.E. Jones and S. Riddell-Mason, Ten different dietary fibers have significantly different effects on plasma and liver lipids of cholesterol-fed rats, J Nutr 124 (1994), pp. 78–83.
17. J.W. Anderson, D.A. Deakins, T.L. Floore, B.M. Smith and S.E. Whitis, Dietary fiber and coronary heart disease, Crit Rev Food Sci Nutr 29 (1990), pp. 95–147.
18. A.C. Frati-Munari, J.A. Fernandez-Harp, M. Becerril, A. Chavez-Negrete and M. Banales-Ham, Decrease in plasma lipids, glycemia and body weight by Plantago psyllium in obese and diabetic patients, Arch Invest Med 14 (1983), pp. 259–268.
19. L.P. Bell, K. Hectorne, H. Reynolds, T.K. Balm and D.B. Hunninghake, Cholesterol-lowering effects of psyllium hydrophilic mucilloid Adjunct therapy to a prudent diet for patients with mild to moderate hypercholesterolemia, JAMA 261 (1989), pp. 3419–3423 .
20. J.W. Anderson, L.D. Allgood, A. Lawrence, L.A. Altringer, G.R. Jerdack and D.A. Hengehold et al., Cholesterol-lowering effects of psyllium intake adjunctive to diet therapy in men and women with hypercholesterolemia: meta-analysis of 8 controlled trials, Am J Clin Nutr 71 (2000), pp. 472–479.
21. J.W. Anderson, M.H. Davidson, L. Blonde, W.V. Brown, W.J. Howard and H. Ginsberg et al., Long-term cholesterol-lowering effects of Psyllium as an adjunct to diet therapy in the treatment of hypercholesterolemia, Am J Clin Nutr 71 (2000), pp. 1433–1438.