Safety of Dietary Undenatured Type II Collagen: A Pilot Open-Label Overdose Clinical Investigation

Background: In advancing age population worldwide, joint discomfort and poor locomotive functions are symptoms, which are often detected. Aggravation of such symptoms potentially develops into osteoarthritis (OA) as characterized by the loss of articular cartilage in the joints of the hand, spine, knee, foot, and hip. For joint health complications, selected functional foods are frequently supplemented orally to alleviate such symptoms. In Japan, Foods with Function Claims (FFC) regulatory system is now positioned within the framework of “so-called health foods” allowing to make functional claims such as brain health and weight control claims. Moreover, a wide variety of knee joint care FFC products are presently available in the marketplace and have attracted much attention of the elderly people, expecting improvements in joint locomotive functions such as walking, sitting, standing, and climbing the stairs for the quality of life (QOL). Supplementation of undenatured type II collagen powder (NEXT-II®) in hard capsules has been clinically proven to improve such joint functions fulfilling part of the FFC rigorous guidelines, while ensuring adequate safety as foods is a crucial prerequisite for filing FFC product dossier.Methods: Twenty-two healthy male and female volunteers (age = 20-74 years) participated in this pilot open-label overdose clinical trial over a period of 4 consecutive weeks. All subjects were also monitored and assessed additional 2 weeks after the completion of the NEXT-II® supplementation period as washout or supplement-free period. Subjects took a 10-fold (10-X) dose of NEXT-II® (400 mg NEXT-II/day containing 32 mg of undenatured type II collagen/day). Daily recommended dose of NEXT-II® is 40 mg/day (containing 3.2 mg of undenatured type II collagen/day) after breakfast. Physical health examination, hematological analysis, blood ,biochemistry examination, and urinalysis were performed. All subjects completed the supplementation of NEXT-II® for 4 weeks and had additional 2 weeks of washout or supplement-free period. All subjects recorded daily diaries. Results: Results demonstrated no significant differences at 0 week (baseline), 2 weeks, and 4 weeks of NEXT-II®supplementation. Furthermore, no significant differences were observed even after 2 weeks of the washout period. No adverse events were observed.Conclusions: Supplementation of 10-fold dose of NEXT-II® to the volunteers was well-tolerated and exhibited the broad-spectrum safety without observing any adverse effects in healthy Japanese subjects.Keywords: Undenatured type II collagen, NEXT-II®, Safety, Overdose supplementation, Clinical study, Foods with Function Claims (FFC)