Ketogenic diet ameliorates inflammation by inhibiting the NLRP3 inflammasome in osteoarthritis.

BACKGROUND: The nucleotide-binding domain, leucine-rich repeat, and pyrin domain-containing protein 3 (NLRP3) inflammasome has been reported to be involved in the pathological process of osteoarthritis (OA) inflammation. Here, we investigated the ketogenic diet (KD), which has been previously demonstrated to inhibit NLRP3 inflammasome activation, to elucidate its protective mechanism against OA in rats. METHODS: Anterior cruciate ligament transaction (ACLT) together with partial medial meniscectomy was used to create a rat knee joint OA model. After treatment with KD or standard diet (SD) for 8 weeks, the knee specimens were obtained for testing. RESULTS: The KD significantly increased the content of ß-hydroxybutyrate (ßOHB) in rats. Compared to the SD group, the KD significantly reduced the damage caused by OA in the articular cartilage and subchondral bone. The NLRP3 inflammasome and inflammatory cytokines interleukin-1 ß (IL-1ß) and IL-18 were significantly increased in the SD group compared with the sham group, while their expression was significantly decreased in rats treated with the KD. In addition, MMP13 was significantly decreased in the KD group compared to that in the SD group, while COL2 was significantly increased. CONCLUSIONS: KD can protect the articular cartilage and subchondral bone in a rat OA model by inhibiting NLRP3 inflammasome activation and reducing the OA inflammatory response.

Efficacy of a dietary supplement in dogs with osteoarthritis: A randomized placebo-controlled, double-blind clinical trial.

This study is a randomized, placebo-controlled, double-blinded trial performed to investigate the effects of a dietary supplement containing a mixture of Boswellia serrata Roxb., chlorophyll, green tea extract, glucosamine, chondroitin sulfate, hyaluronic acid, and further in the manuscript: non-hydrolised type II collagen in dogs with osteoarthritis (OA). A total of 40 dogs were enrolled in the study, they were randomly divided in control (CTR) and treatment (TRT) groups. The TRT group received the dietary supplement for 60 days. The CTR group received a placebo for the same number of days. All the subjects had veterinary evaluations during the trial and owners were requested to fill in questionnaires on chronic pain using the Helsinki Chronic Pain Index. The product was easy to administer and no side effects were reported. Combining results from veterinarian and owner evaluations, the tested product proved to be significantly beneficial in alleviating pain and in reducing the clinical signs in dogs with OA.

Effects of Protein-Rich Nutritional Composition Supplementation on Sarcopenia Indices and Physical Activity during Resistance Exercise Training in Older Women with Knee Osteoarthritis.

Older adults with knee osteoarthritis (KOA) are at high risk of sarcopenia. Protein-rich nutritional composition supplementation (PS) combined with resistance exercise training (RET) improves muscle gains and facilitates physical activity in older adults. However, whether PS augments the effects of RET on muscle mass and PA in patients with KOA remains unclear. Therefore, this study identified the effects of PS on sarcopenic indices and PA in older women with KOA subjected to an RET program. Eligible older women aged 60-85 years and diagnosed as having KOA were randomly assigned to either the experimental group (EG) or the control group (CG). Both groups performed RET twice a week for 12 weeks. The EG received additional PS during this period. Outcome measures included appendicular lean mass index, walking speed, physical activity, and scores on the Western Ontario and McMaster Universities Osteoarthritis Index-WOMAC). All measures were tested at baseline and after intervention. With participant characteristics and baseline scores as covariates, analysis of variance was performed to identify between-group differences in changes in all outcome measures after intervention. Statistical significance was defined as p < 0.05. Compared with the CG, the EG achieved greater changes in appendicular lean mass index (adjusted mean difference (aMD) = 0.19 kg/m2, p < 0.01), physical activity (aMD = 30.0 MET-hour/week, p < 0.001), walking speed (aMD = 0.09 m/s, p < 0.05), and WOMAC global function (aMD = -8.21, p < 0.001) after intervention. In conclusion, PS exerted augmentative effects on sarcopenic indices, physical activity, and perceived global WOMAC score in older women with KOA through 12 weeks of RET.

A Mixture Containing Fermented Achyranthes japonica Nakai Ameliorates Osteoarthritis in Knee Joints of Monoiodoacetate-Injected Rats.

We demonstrated the effect of a mixture containing fermented Achyranthes japonica Nakai (FS) in the context of a monosodium iodoacetate (MIA)-induced osteoarthritis animal model. The mineralization, anabolic and catabolic factors, and the amount of cytokines within the articular cartilage of rats were measured after administration of MIA. We found that dietary supplementation with methylsulfonylmethane (positive control) and FS (FS 100 mg/kg body weight [b.w.] and FS 300 mg/kg b.w.) effectively suppressed pathological changes in the knee joint and inhibited changes in the architectural and mineralization parameters. In addition, prostaglandin E2 (PGE2) and proinflammatory cytokines in the serum and catabolic factors, including matrix metalloproteinase (MMP)-3 and MMP-7 in articular cartilage, were decreased by dietary supplementation with FS in MIA-induced osteoarthritis. Based on these findings, we suggest that FS can be used for the development of potential therapies for osteoarthritis.

The Effect of Low-Carbohydrate and Low-Fat Diets on Pain in Individuals with Knee Osteoarthritis.

OBJECTIVE: Osteoarthritis is the most prominent form of arthritis, affecting approximately 15% of the population in the United States. Knee osteoarthritis (KOA) has become one of the leading causes of disability in older adults. Besides knee replacement, there are no curative treatments for KOA, so persistent pain is commonly treated with opioids, acetaminophen, and nonsteroidal anti-inflammatory drugs. However, these drugs have many unpleasant side effects, so there is a need for alternative forms of pain management. We sought to test the efficacy of a dietary intervention to reduce KOA. DESIGN: A randomized controlled pilot study to test the efficacy of two dietary interventions. SUBJECTS: Adults 65-75 years of age with KOA. METHODS: Participants were asked to follow one of two dietary interventions (low-carbohydrate [LCD], low-fat [LFD]) or continue to eat as usual (control [CTRL]) over 12 weeks. Functional pain, self-reported pain, quality of life, and depression were assessed every three weeks. Serum from before and after the diet intervention was analyzed for oxidative stress. RESULTS: Over a period of 12 weeks, the LCD reduced pain intensity and unpleasantness in some functional pain tasks, as well as self-reported pain, compared with the LFD and CTRL. The LCD also significantly reduced oxidative stress and the adipokine leptin compared with the LFD and CTRL. Reduction in oxidative stress was related to reduced functional pain. CONCLUSIONS: We present evidence suggesting that oxidative stress may be related to functional pain, and lowering it through our LCD intervention could provide relief from pain and be an opioid alternative.

Calorie restriction with regular chow, but not a high-fat diet, delays onset of spontaneous osteoarthritis in the Hartley guinea pig model.

BACKGROUND: Obesity is a leading risk factor for osteoarthritis (OA). In contrast, calorie restriction (CR) may lessen OA due to improved systemic inflammatory status and reduced weight-bearing. The aim of this study was to determine how CR with regular chow versus a high-fat diet (HFD) alters OA progression using the Hartley guinea pig model of disease. METHODS: Twenty-four male guinea pigs were allocated to four groups at 2 months of age: (1) ad libitum regular chow (obese), (2) CR regular chow (lean), (3) ad libitum HFD, and (4) CR HFD. Animals in both HFD groups ate identical amounts and were combined into one HFD group for analyses. At 5 months, hind limbs were harvested for microcomputed tomography (microCT) and histopathologic evaluation of knee OA. Total body, gonad fat, and infrapatellar fat pad (IFP) masses were recorded. IFPs were collected for gene expression analysis. Immunohistochemistry for monocyte chemoattractant protein-1 (MCP-1) was performed on intact joints. Serum was utilized for protein C3 measurement. All data were compared using ordinary one-way ANOVA analyses with Tukey's post-hoc tests. RESULTS: Body mass in the lean and HFD groups were similar and lower than the obese group. Despite this, gonad fat pads in the HFD group were comparable to the obese group. MicroCT and histologic OA scores were similar in obese and HFD groups; both scores were significantly lower in the lean group. Obese and HFD groups displayed increased gene expression of pro-inflammatory and catabolic mediators in IFPs relative to lean animals. Consistent with this, immunohistochemistry for MCP-1 in knee joints demonstrated strong positive staining in obese and HFD groups but was minimally detected in lean animals. Serum protein C3 levels were also statistically higher. CONCLUSIONS: This study demonstrated that CR with a regular chow diet lessened knee OA in the Hartley guinea pig and was associated with decreased local and systemic inflammation compared to obese animals. HFD animals, although under CR conditions, had OA scores and inflammatory markers similar to obese animals. Thus, diet composition, and not solely body weight, may be a key factor in development of OA.

The Association between Dietary Magnesium Intake and Magnetic Resonance Parameters for Knee Osteoarthritis.

The aim of the study was to evaluate the relationship between dietary magnesium (Mg) intake and prevalence of knee osteoarthritis (OA), a topic poorly explored in the literature. Overall, 783 people participating in the Osteoarthritis Initiative (59.8% females; mean age: 62.3 years) and having an MRI assessment were enrolled in this cross-sectional study. Mg intake was measured with a semi-quantitative food frequency questionnaire, and its association with knee OA was evaluated for an increased intake of 100 mg/day. Using an adjusted linear regression analysis, a higher Mg intake (i.e., increase of 100 mg/day) corresponded to a significant increase in mean cartilage thickness, cartilage volume at medial tibia, cartilage volume and mean cartilage thickness at central medial femur, and cartilage volume and mean cartilage thickness in the central medial tibiofemoral compartment. In conclusion, an increased Mg dietary intake is associated with a better knee cartilage architecture, also when adjusting for potential confounders, suggesting a potential role of Mg in the prevention and treatment of knee OA.

Weight loss exclusively through diet for knee osteoarthritis. / Weight loss exclusively through diet for knee osteoarthritis.

INTRODUCTION: Knee osteoarthritis is a highly prevalent chronic disease, associated with various risk factors and with multiple treatment options. Overweight is among the main risk factors and also constitutes an aggravating factor of the symptoms. It has been suggested that weight loss would be able to improve symptoms and to stop the progression. It can be achieved by several methods: exercise, diet, drugs, surgery, or a combination of them. Apparently, diet is a reasonable option given its availability, low technical complexity and greater acceptability, especially in the population susceptible to developing knee osteoarthritis, but it is not clear whether the benefit of diet as the only intervention leads to symptomatic improvement. METHODS: We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. RESULTS AND CONCLUSIONS: We identified seven systematic reviews including six primary studies overall, all corresponding to randomized trials. We concluded diet may improve functionality and quality of life, with probably minimal or no adverse effects. However, we are uncertain whether diet reduces pain as the certainty of the evidence has been assessed as very low.

INTRODUCCIÓN: La artrosis de rodilla es una enfermedad crónica altamente prevalente, asociada a diversos factores de riesgo y con múltiples opciones para su tratamiento. Dentro de los factores de riesgo más importantes se encuentra el sobrepeso, que además constituye un factor agravante de los síntomas. Se ha planteado que la baja de peso es beneficiosa en el manejo de los síntomas y detención de la progresión, pudiendo lograrse a través de distintos métodos: ejercicio, dietas, fármacos, cirugía, o bien una combinación de ellos. Aparentemente, la dieta constituye una opción razonable dado su disponibilidad, baja complejidad técnica y mayor disposición a una buena adherencia, especialmente en población susceptible a desarrollar artrosis de rodilla, pero no existe claridad sobre el beneficio de la dieta como medio exclusivo para lograr una mejoría en los síntomas. MÉTODOS: Realizamos una búsqueda en Epistemonikos, la mayor base de datos de revisiones sistemáticas en salud, la cual es mantenida mediante búsquedas en múltiples fuentes de información, incluyendo MEDLINE, EMBASE, Cochrane, entre otras. Extrajimos los datos desde las revisiones identificadas y analizamos los datos de los estudios primarios. Con esta información, generamos un resumen estructurado denominado FRISBEE (Friendly Summaries of Body of Evidence using Epistemonikos), siguiendo un formato preestablecido, que incluye mensajes clave, un resumen del conjunto de evidencia (presentado como matriz de evidencia en Epistemonikos), metanálisis del total de los estudios cuando sea posible, una tabla de resumen de resultados con el método GRADE y una sección de otras consideraciones para la toma de decisión. RESULTADOS Y CONCLUSIONES: Identificamos siete revisiones sistemáticas, que en conjunto incluyeron seis estudios primarios, todos correspondientes a ensayos aleatorizados. Concluimos que la dieta podría mejorar la funcionalidad y la calidad de vida, con probablemente mínimos o nulos efectos adversos. Sin embargo, no está claro si disminuye el dolor porque la certeza de la evidencia es muy baja.

The influence of probiotic diet and chondroitin sulfate administration on Ptgs2, Tgfb1 and Col2a1 expression in rat knee cartilage during monoiodoacetate-induced osteoarthritis.

BACKGROUND: Osteoarthritis (OA) is a common worldwide disease induced by a wide range of biochemical processes, mainly inflammation and degradation of collagen. The aim of this study, was to describe the effect of a multistrain probiotic (PB) and chondroitin sulfate (CS), administered separately or in combination, on the expression of Ptgs2, Tgfb1 and Col2a1 during monoiodoacetate-induced OA in male rats. METHODS: OA was induced in male rats by injecting monoiodoacetate in right hind knee. Therapeutic groups received 3 mg/kg of CS for 28 days and/or 1.4 g/kg of multistrain PB for 14 days. Knee cartilage were taken 30 days after monoiodoacetate injection. RNA was extracted and the expression of Ptgs2, Tgfb1 and Col2a1 were analyzed using SYBR Green 1-step real-time quantitative polymerase chain reaction. RESULTS: Induction of OA caused an upregulation in Ptgs2, Tgfb1 expression, and downregulation of Col2a1. Separate administration of PB and CS reduced Ptgs2 and Tgfb1 expressions. Their combined administration significantly decreased the expression of these pro-inflammatory cytokines, comparable to controls. Expression of Col2a1 showed similar behavior, with upregulation in therapeutic group with separate administration and the cumulative effects in case of co-administration. CONCLUSIONS: The multistrain PB diet may offer a perspective to improve the standard treatment of OA and, necessitates further investigation with clinical trials.

Blueberries Improve Pain, Gait Performance, and Inflammation in Individuals with Symptomatic Knee Osteoarthritis.

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)-1ß, 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.

Effect of weight losing on the clinical status improvement of patients with knee osteoarthritis.

OBJECTIVE: Osteoarthritis causes severe pain and disability in joints, one of the most prevalent involved joints is the knee joint. There are several therapeutics ways to control pain and disability, but almost none of them are definite treatment. In this article, we tried to reveal the effect of weight loss on improving symptoms of knee osteoarthritis as an effective and permanent therapeutic approach. METHODS: We chose 62 patients with grade 1-2 (mild to moderate) knee osteoarthritis and divided them equally into case and control groups. Patients should not had used NSAIDs at least for 6 months before study initiation. Symptoms severity was measured by WOMAC and VAS questionnaires before and after 3 months follow up. Weight and BMI were recorded too. Case group was suggested to have weight loss diet of less fat and carbohydrates and control group did not have any limitation. RESULTS: Comparison of variables' average of case and control groups was not logistically meaningful at the initiation and after the end of the study. But there was a meaningful correlation between variables' changes and lifestyle change in both groups, especially in WOMAC and VAS scores. All variables in case group had statistically meaningful differences between their amounts at the beginning and after the end of the study, on the contrary of the control group. CONCLUSION: In the comparison of our study with similar studies in the world. We deduced that weight loss can improve symptoms of knee osteoarthritis even in short time weight loss diet (3 months). TRIAL REGISTRATION NUMBER: ZUMS.REC.1394.94.

Strawberries decrease circulating levels of tumor necrosis factor and lipid peroxides in obese adults with knee osteoarthritis.

OBJECTIVE: Knee osteoarthritis (OA) is increasingly prevalent in obese people, who often have high cardio-metabolic risk factors. Among the few available non-surgical approaches, nutraceuticals have gained popularity, and dietary berries have mitigated arthritis symptoms in observational and animal studies. Clinical studies in OA are sparse, but recently we reported that strawberry supplementation can mitigate pain and reduce inflammatory markers in adults with knee OA. This study extends those observations. METHODS: We conducted a randomized cross-over double-blind placebo-controlled trial on the effects of dietary freeze-dried strawberries on obesity-related hormones, biomarkers of inflammation and lipid peroxidation. Seventeen subjects (4 men, 13 women; age 57 ± 3 year) were randomized to strawberry supplements (50 g day-1 for 12 weeks) vs. placebo (50 g day-1, matched for calories and fiber), for two 12-week intervention periods, separated by 2-week washout phase. RESULTS: Among 24 biomarkers of inflammation examined (Bioplex-Pro human inflammation panel), 12 were detectable in all samples. Among these, high-sensitivity TNF-α (hs-TNF-α) and the soluble tumor necrosis factor receptor (sTNF-R2) were significantly decreased after strawberry consumption (p < 0.05). There were no changes in other biomarkers of the TNF super family, such as APRIL and BAFF. Among serum biomarkers of oxidative stress, 4-hydroxy-2-nonenal (4-HNE) and conjugated dienes were also reduced (p < 0.05). No changes were observed in body weight, serum obesity-related hormones, or osteocalcin. CONCLUSION: Strawberries lowered TNF-α, and lipid peroxidation products in obese adults with knee OA. Since, they also mitigate pain, these findings merit further investigation in larger trials.

The association between the Mediterranean diet and magnetic resonance parameters for knee osteoarthritis: data from the Osteoarthritis Initiative.

The Mediterranean diet appears to be beneficial for osteoarthritis (OA), but the few data available regarding the association between the diet and the condition are limited to X-ray and clinical findings. The current study aimed to investigate the association between adherence to the Mediterranean diet and knee cartilage morphology, assessed using magnetic resonance (MRI) in a cohort of North American participants. Seven hundred eighty-three participants in the Osteoarthritis Initiative (59.8% females; mean age 62.3 years) in possession of a MRI assessment (a coronal 3D FLASH with Water Excitation MR sequence of the right knee) were enrolled in our cross-sectional study. Adherence to the Mediterranean diet was evaluated using a validated Mediterranean diet score (aMED). The strength of the association between aMED and knee MRI parameters was gauged using an adjusted linear regression analysis, expressed as standardized betas with 95% confidence intervals (CIs). Using an adjusted linear regression analysis, each increase of one standard deviation (SD) in the aMED corresponded to a significant increase in the central medial femoral cartilage volume (beta = 0.12; 95%CI 0.09 to 0.15), in the mean central medial femoral cartilage thickness (beta = 0.13; 95%CI 0.01 to 0.17), in the cartilage thickness of the mean central medial tibiofemoral compartment (beta = 0.12; 95%CI 0.09 to 0.15), and in the cartilage volume of the medial tibiofemoral compartment (beta = 0.09; 95%CI 0.06 to 0.12). Higher adherence to a Mediterranean diet was found to be associated with a significant improvement in knee cartilage as assessed by MRI, even after adjusting for potential confounding factors.

Epigallocatechin-3-O-gallate modulates global microRNA expression in interleukin-1ß-stimulated human osteoarthritis chondrocytes: potential role of EGCG on negative co-regulation of microRNA-140-3p and ADAMTS5.

PURPOSE: MicroRNAs (miRNAs) are short, non-coding RNAs involved in almost all cellular processes. Epigallocatechin-3-O-gallate (EGCG) is a green tea polyphenol and is known to exert anti-arthritic effects by inhibiting genes associated with osteoarthritis (OA). This study was undertaken to investigate the global effect of EGCG on interleukin-1ß (IL-1ß)-induced expression of miRNAs in human chondrocytes. METHODS: Human chondrocytes were derived from OA cartilage and then treated with EGCG and IL-1ß. Human miRNA microarray technology was used to determine the expression profile of 1347 miRNAs. Microarray results were verified by taqman assays and transfection of chondrocytes with miRNA inhibitors. RESULTS: Out of 1347 miRNAs, EGCG up-regulated expression of 19 miRNAs and down-regulated expression of 17 miRNAs, whereas expression of 1311 miRNAs remains unchanged in IL-1ß-stimulated human OA chondrocytes. Bioinformatics approach showed that 3`UTR of ADAMTS5 mRNA contains the 'seed-matched-sequence' for hsa-miR-140-3p. IL-1ß-induced expression of ADAMTS5 correlated with down-regulation of hsa-miR-140-3p. Importantly, EGCG inhibited IL-1ß-induced ADAMTS5 expression and up-regulated the expression of hsa-miR-140-3p. This EGCG-induced co-regulation between ADAMTS5 and hsa-miR-140-3p becomes reversed in OA chondrocytes transfected with anti-miR-140-3p. CONCLUSIONS: This study provides an important insight into the molecular basis of the reported anti-arthritic effects of EGCG. Our data indicate that the potential of EGCG in OA chondrocytes may be related to its ability to globally inhibit inflammatory response via modulation of miRNAs expressions.

Strawberries Improve Pain and Inflammation in Obese Adults with Radiographic Evidence of Knee Osteoarthritis.

Osteoarthritis (OA), the most common form of arthritis, is a significant public health burden in U.S. adults. Among its many risk factors, obesity is a key player, causing inflammation, pain, impaired joint function, and reduced quality of life. Dietary polyphenols and other bioactive compounds in berries, curcumin, and tea have shown effects in ameliorating pain and inflammation in OA, but few clinical studies have been reported. The purpose of the present study was to examine the effects of dietary strawberries on pain, markers of inflammation, and quality of life indicators in obese adults with OA of the knee. In a randomized, double-blind cross-over trial, adults with radiographic evidence of knee OA (n = 17; body mass index (BMI): (mean ± SD) 39.1 ± 1.5; age (years): 57 ± 7) were randomized to a reconstituted freeze-dried strawberry beverage (50 g/day) or control beverage daily, each for 12 weeks, separated by a 2-week washout phase (total duration, 26 weeks). Blood draws and assessments of pain and quality of life indicators were conducted using the Visual Analog Scale for Pain (VAS Pain), Measures of Intermittent and Constant Osteoarthritis Pain (ICOAP), and Health Assessment Questionnaire-Disability Index (HAQ-DI) questionnaires, which were completed at baseline and at weeks 12, 14, and 26 of the study. Among the serum biomarkers of inflammation and cartilage degradation, interleukin (IL)-6, IL-1ß, and matrix metalloproteinase (MMP)-3 were significantly decreased after strawberry vs. control treatment (all p < 0.05). Strawberry supplementation also significantly reduced constant, intermittent, and total pain as evaluated by the ICOAP questionnaire as well as the HAQ-DI scores (all p < 0.05). No effects of treatment were noted on serum C-reactive protein (CRP), nitrite, glucose, and lipid profiles. Dietary strawberries may have significant analgesic and anti-inflammatory effects in obese adults with established knee OA.

Dietary and Supplemental Vitamin C and D on Symptom Severity and Physical Function in Knee Osteoarthritis.

Vitamins C and D have been associated with decreasing pain and increasing function but these associations are not definitive. This cross-sectional study explores what relationships supplemental and dietary intake of vitamins C and D have on pain severity and physical function in patients with knee osteoarthritis. Using data from the Osteoarthritis Initiative, we performed regression analyses to examine relationships between vitamins C and D, pain, and function. Dietary vitamin D and dietary vitamin C were divided into >90th, 50th-90th, and <50th percentile. The high percentile group for supplemental vitamin D was divided into >85th percentile, whereas the high percentile group for supplemental vitamin C was divided into >90th percentile. We found the 90th/85th percentile levels of dietary and supplemental vitamin D to be positively associated with pain (ß = 0.180; p = 0.028) and inversely related to physical function (ß = -0.150, p = 0.028), respectively. Daily intake of vitamin C showed no statistical significance. We found that supplementary vitamin D was strongly associated with lessened disability for knee OA patients. The unexpected finding that associated dietary vitamin D with greater knee pain merits further study.

Effect of a Mediterranean Type Diet on Inflammatory and Cartilage Degradation Biomarkers in Patients with Osteoarthritis.

OBJECTIVES: To investigate the effects of a Mediterranean type diet on patients with osteoarthritis (OA). PARTICIPANTS: Ninety-nine volunteers with OA (aged 31 - 90 years) completed the study (83% female). SETTING: Southeast of England, UK. DESIGN: Participants were randomly allocated to the dietary intervention (DIET, n = 50) or control (CON, n = 49). The DIET group were asked to follow a Mediterranean type diet for 16 weeks whereas the CON group were asked to follow their normal diet. MEASUREMENTS: All participants completed an Arthritis Impact Measurement Scale (AIMS2) pre-, mid- and post- study period. A subset of participants attended a clinic at the start and end of the study for assessment of joint range of motion, ROM (DIET = 33, CON = 28), and to provide blood samples (DIET = 29, CON = 25) for biomarker analysis (including serum cartilage oligomeric matrix protein (sCOMP) (a marker of cartilage degradation) and a panel of other relevant biomarkers including pro- and anti-inflammatory cytokines). RESULTS: There were no differences between groups in the response of any AIMS2 components and most biomarkers (p > 0.05), except the pro-inflammatory cytokine IL-1α, which decreased in the DIET group (~47%, p = 0.010). sCOMP decreased in the DIET group by 1 U/L (~8%, p = 0.014). There was a significant improvement in knee flexion and hip rotation ROM in the DIET group (p < 0.05). CONCLUSIONS: The average reduction in sCOMP in the DIET group (1 U/L) represents a meaningful change, but the longer term effects require further study.