Osteoarthritis is a progressive degenerative joint condition characterized by gradual breakdown of cartilage, remodeling of subchondral bone, synovial inflammation, oxidative stress, and altered joint biomechanics. The condition commonly affects the knees, hips, spine, hands, and weight-bearing joints. Cartilage degradation is associated with elevated inflammatory signaling molecules, increased matrix metalloproteinase activity, oxidative injury, mitochondrial dysfunction, and chronic low-grade inflammation within the joint environment. Degeneration of cartilage reduces the protective cushioning between bones, leading to stiffness, pain, reduced mobility, crepitus, swelling, and decreased functional movement. Inflammatory signaling pathways including NF-κB, MAPK, COX-derived prostaglandin pathways, and oxidative stress responses contribute to tissue remodeling and cartilage degradation. Elevated inflammatory mediators can increase destruction of collagen and extracellular matrix proteins that are essential for joint stability and flexibility. Oxidative stress also contributes to mitochondrial dysfunction in chondrocytes, impairing normal tissue maintenance and increasing inflammatory signaling within the joint space. Excess body weight, chronic inflammatory dietary patterns, low antioxidant intake, physical inactivity, repetitive mechanical stress, and metabolic dysfunction are associated with worsening osteoarthritis progression. Increased adiposity may contribute to inflammatory cytokine production including IL-6 and TNF-α signaling, which can influence cartilage degradation and inflammatory pain pathways. Dietary patterns rich in ultra-processed foods, oxidized fats, refined sugars, and inflammatory compounds are associated with elevated oxidative burden and inflammatory signaling. A whole-food plant-based dietary pattern emphasizing vegetables, legumes, berries, herbs, mushrooms, seeds, whole grains, and polyphenol-rich foods may help support antioxidant defenses, healthy inflammatory balance, endothelial health, mitochondrial function, and tissue maintenance. Phytochemicals including quercetin, curcumin, anthocyanins, sulforaphane, EGCG, and luteolin have been studied for their interaction with inflammatory signaling pathways associated with joint degeneration. Fiber-rich plant foods also support gut microbiome signaling and short-chain fatty acid production, which are associated with immune and inflammatory regulation. Nutritional strategies emphasizing potassium-rich vegetables, magnesium-containing legumes and seeds, vitamin C-rich fruits, carotenoid-containing vegetables, and polyphenol-rich herbs may support connective tissue maintenance, antioxidant protection, and inflammatory pathway modulation. Consistent intake of diverse plant foods may support long-term joint function, mobility, connective tissue integrity, and metabolic balance associated with osteoarthritis support.