Traditionally, hyaluronic acid has been used as an injectable to promote joint health and support joint structure. There have also been questions regarding the absorbability of hyaluronic acid when taken orally. Research shows that oral hyaluronic acid is in fact absorbed and that it functions in at least three important ways. Hyaluronic acid is a large molecule with repeating subunits that, when taken orally, naturally goes through the process of digestion in the digestive tract. Studies show that 1) A portion of the hyaluronic acid is absorbed intact, 2) A portion of it is broken down into its component sugars and absorbed in this way (providing building blocks the body can use to remanufacture hyaluronic acid, and 3) Hyaluronic Acid acts to stimulate the growth of beneficial bacteria in the digestive tract, which promote immune system health and lead to overall health of the joints, skin and connective tissue throughout the body. These three unique and distinctly separate mechanisms of activity illustrate the ability of oral hyaluronic acid to benefit and support the body’s connective tissue.
To reaffirm the efficacy of oral hyaluronic acid for joint support, let’s look at the results of an important Japanese study. This study, which was published in 2008, was carried out to assess the efficacy of oral hyaluronic acid in promoting healthy joint function and mobility. Fifteen individuals with achy knees were supplemented with 240 mg of highly purified hyaluronic acid daily for twelve weeks. Positive results were evident after 4 weeks of supplementation as the individuals had significant improvements in knee joint function and comfort. The benefits continued throughout the duration of the study, showing that oral hyaluronic acid supplements are effective for promoting healthy joint function.11
Now that we know that studies affirm the effectiveness of oral hyaluronic acid, let’s look at evidence supporting the three mechanisms of activity. Bioavailability studies in animals show that hyaluronic acid taken orally reaches joint tissue. Radioactively-labeled particles of hyaluronic acid were found to reach the skin, bone and joints of rats after oral administration, showing that a percentage of orally administered hyaluronic acid is absorbed intact.12 A further percentage of hyaluronic acid taken as supplements is digested and broken down into its component molecules. These components are absorbed into the bloodstream, providing the body with the building blocks necessary to produce hyaluronic acid on its own, allowing it to replenish its own stores. Finally, a very interesting study was carried out in which rats were administered hyaluronic acid orally. Researchers found that the orally administered nutrient was fermented by gut bacteria as a source of nutrition. Hyaluronic acid was shown to act as a prebiotic, as it increased the level of Lactobacillus and Bifidobacterium species in the intestinal tract.13 Taking these important studies into account, we can see that oral hyaluronic acid supplements have both direct and indirect effects in supporting the health of our joints, skin and connective tissue. Given its broad range of potential benefits, hyaluronic acid is a crucial and important nutrient for healthy aging.
11. Sato T, Iwaso H. An Effectiveness Study of Hyaluronic Acid (Hyabest® (J)) in the Treatment of Osteoarthritis of the Knee. J New Rem & Clin 2008;57(2):128-137.
12. Balogh L, Polyak A, Mathe D, Kiraly R, Thuroczy J, Terez M, Janoki G, Ting Y, Bucci LR, Schauss AG. Absorption, uptake and tissue affinity of high-molecular-weight hyaluronan after oral administration in rats and dogs. J Agric Food Chem 2008 Nov 26;56(22):10582-93.
13. Ishibashi G, Yamagata T, Rikitake S, Takiguchi Y. Digestion and Fermentation of Hyaluronic Acid. Journal for the Integrated Study of Dietary Habits 2002; 13(2): 107-111.