The Effects of GreenShell Mussel Powder (Brand-Named PERNAULTRA) on Physical Performance and Subjective Pain, Symptoms, and Function Measures in Knee Osteoarthritis: A 6-Mo Randomized, Double-Blind, Placebo-Controlled Trial

Osteoarthritis (OA) can cause disability and reduce quality of life (QoL). This study aimed to determine whether GreenShell mussel (GSM) powder (PERNAULTRA) consumption was more effective than placebo at improving physical performance and subjective measures of symptoms and function in adults with early signs of knee OA. The Researching Osteoarthritis and GSM study was a 6-mo randomized, double-blind, placebo-controlled trial in adults aged 55–80 y, screened for signs of OA (n = 120, 65.9 ± 6.43 y, 63% female). Participants consumed either 3 g of powdered whole GSM or placebo (pea protein) daily. Baseline and end data collection included 30-s chair stand, stair test, 40-m fast-paced walk test, Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire categorized into 5 subscales [pain (P), symptoms except pain (S), function in activities of daily living (ADL), function in sports/recreation (SP), and QoL], a measure of Intermittent and Constant Osteoarthritis Pain, and visual analog scale of pain and symptoms. Visual analog scale symptoms showed a significantly greater reduction in percentage change for GSM than that for placebo [−28.1 (−59.2, 43.2) compared with 0.00 (−28.6, 100); P = 0.03]. Further, a trend for improvement in percentage change for GSM compared with placebo was seen in 40m fast-paced walk [2.51 (−3.55, 8.12) compared with 0.20 (−6.58, 4.92); P = 0.09], KOOS-SP [11.4 (−4.48, 27.0) compared with 0.00 (−11.1, 17.7); P = 0.09], and Intermittent and Constant Osteoarthritis Pain intermittent pain scale [−27.7 (−77.3, 0.00) compared with −14.6 (−50.0, 36.4); P = 0.08]. In those with body mass index (BMI; in kg/m2)