Diet in Knee Osteoarthritis-Myths and Facts.

Knee osteoarthritis (OA) is a common degenerative joint disease affecting global health. Its increasing prevalence, particularly among aging populations, remains a leading cause of disability. Besides conventional pharmacological and surgical treatments, dietary interventions are promising strategies to alleviate OA symptoms and progression. Unfortunately, scientific evidence does not support many commonly used, misleading ideas about nutrition in knee OA. Recent data highlight the detrimental effects of high-carbohydrate and high-fat diets, particularly those rich in refined sugars and saturated fats, which exacerbate systemic inflammation and contribute to cartilage degradation. Conversely, diets rich in omega-3 fatty acids, polyphenols, and dietary fiber have shown anti-inflammatory and chondroprotective properties. A Mediterranean diet rich in these nutrients effectively prevents the development of OA and its comorbidities, including obesity and cardiovascular disease. The role of supplements, such as glucosamine, chondroitin, and vitamin D, is questioned due to the lack of evidence supporting their efficacy in treating knee OA. Despite dietary recommendations published annually, there is still a need to debunk many myths that are not confirmed by current evidence. The significant research gaps require more extensive, controlled studies to establish evidence-based dietary recommendations (particularly carbohydrates, dietary fiber, and antioxidant intake). This comprehensive review provides insight into the various indications for the impact of nutrition on knee OA, focusing on key nutrients such as carbohydrates, fats, proteins, antioxidants, and selected micronutrients, providing the clinician with ready-to-implement nutritional modifications. Such an analysis may help clinicians and patients incorporate dietary strategies into treating knee OA, emphasizing the need for personalized, sustainable approaches.