Osteoarthritis (OA) is the most common joint disorder in the world and is the most frequent cause of walking related disability among older adults in the US, which brings a significant economic burden and reduces quality of life. The initiation and development of OA typically involves degeneration or progressive loss of the structure and function of articular cartilage. Inflammation is one of the major drives of the progression of OA. Dietary polyphenols have been studied for their anti-inflammatory properties and potential anabolic effects on the cartilage cells. Blueberries are widely consumed and are high in dietary polyphenols, therefore regular consumption of blueberries may help improve OA. The purpose of the present study was to examine the effect of freeze dried whole blueberries on pain, gait performance, and inflammation in individuals with symptomatic knee OA. In a randomized, double-blind trial, adults age 45 to 79 with symptomatic knee OA, were randomized to either consume 40 g freeze-dried blueberry powder (n = 33) or placebo powder (n = 30) daily for four months. Blood draws and assessment of pain and gait were conducted at baseline, two months, and four months. Western Ontario McMaster Osteoarthritis Index (WOMAC) questionnaires were used to assess pain and GAITRite^® electronic walkway was used to evaluate gait spatiotemporal parameters. WOMAC total score and sub-groups, including pain, stiffness, and difficulty to perform daily activities decreased significantly in the blueberry treatment group (p < 0.05), but improvement of WOMAC total score and difficulty to perform daily activities were not observed in the placebo group. Normal walking pace single support percentage for both limbs increased (p = or < 0.007), while double support percentage for both limbs decreased in the blueberry treatment group (p = or < 0.003). No significant changes were observed in plasma concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-10, IL-13, matrix metalloproteinases (MMP)-3, MMP-13, and monocyte chemoattractant protein-1 (MCP-1) in both treatment groups. However, an increasing trend for IL-13 concentration and a decreasing trend in MCP-1 concentration were noted in the blueberry group. The findings of this study suggest that daily incorporation of whole blueberries may reduce pain, stiffness, and difficulty to perform daily activities, while improving gait performance, and would therefore improve quality of life in individuals with symptomatic knee OA.

Background/Objectives: Osteoarthritis is a degenerative joint disease that affects people worldwide. It is characterized by joint pain, synovial inflammation, and the degradation of articular cartilage with subchondral bone. Presently, there is no known cure, and pharmacological treatment options are limited. Blueberries contain phytochemicals, which have been linked to positive health benefits and may offer therapeutic benefits. Therefore, the purpose of this study was to examine the dose-dependent effects of whole blueberries on arthritis symptoms in a monosodium iodoacetate (MIA)-induced rat model of osteoarthritis. Methods: Forty female rats were used for this study. Thirty were injected with MIA to induce joint degradation associated with osteoarthritis. Ten served as controls without MIA induction. The MIA-induced rats were randomized into three groups. All groups were fed a casein-based diet, with two of the MIA-induced groups receiving an addition of whole-blueberry powder at 5% and 10%. Fasted blood specimens and tissues of interest were collected post-euthanasia for analysis. Mechanical allodynia and joint widths were assessed throughout this study. Results: MIA induction resulted in changes in pain behaviors and the development of mechanical allodynia. The MIA injection produced inflammation, pain symptoms, and behaviors that are representative of those observed in humans with osteoarthritis. The incorporation of whole blueberries into diets reduced pain behaviors and inflammation. Conclusions: Overall, whole blueberries showed limited, non-dose-dependent effects in the MIA-induced rat model of osteoarthritis. While some outcomes improved in blueberry-treated groups, the overall results were not consistently significant. These preliminary findings suggest potential biological activity and support the further investigation of blueberries’ therapeutic efficacy.