Omega-3 supplements show promise in fighting osteoarthritis
Last reviewed: 14.06.2024
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A recent study published in the journal Nutrients examined the effectiveness of omega-3 polyunsaturated fatty acids (PUFAs) in modulating the progression of osteoarthritis (OA).
Osteoarthritis is a degenerative joint disease in which the destruction of articular cartilage leads to a pro-inflammatory response. The progression of the disease can be determined by various factors, such as the degree of inflammation, trauma, biomechanics and metabolism.
On articular surfaces, articular cartilage provides low friction and greater load transfer during joint movement. In addition to articular cartilage, osteoarthritis can also negatively affect ligaments, adjacent synovium, and subchondral bone, leading to joint pain.
Symptomatic osteoarthritis is usually treated with exercise programs, education, and weight control programs. Drug treatment is also available, but the presence of comorbidities complicates the use of drug therapy. Therefore, there is an urgent need for alternative treatments to slow the progression of osteoarthritis.
Previous studies have shown that dietary supplements and dietary changes may be beneficial for patients with osteoarthritis. The anti-inflammatory properties of omega-3 PUFAs play a key role in the catabolic and inflammatory processes that contribute to the progression of osteoarthritis.
Omega-3 supplements and reducing inflammation in osteoarthritis
Omega-3 PUFAs have anti-inflammatory effects that have been shown to reduce carcinogenic and vascular biomarkers, including those associated with chronic inflammation, metabolic diseases and musculoskeletal debilitating conditions.
Specialized pro-resolution lipid modulators (SPMs) counter-regulate pro-inflammatory mediators and promote the production of anti-inflammatory mediators at the cellular level through apoptotic cells, cellular debris and phagocytosis of pathogens by macrophages. One study found that administering SPM for eight to twelve weeks resulted in improvements in knee osteoarthritis symptoms.
The ratio of n-6 to n-3 PUFAs is critical in determining the dominance of a pro-inflammatory or anti-inflammatory response. Previous studies have shown that a higher n-6/n-3 ratio was associated with greater osteoarthritis knee pain and functional limitations.
People with high intakes of saturated fatty acids were also found to have decreased joint space width. However, this effect was not observed in those who consumed more PUFAs.
When studying the relationship between PUFAs and synovial fluid taken from knee and shoulder joints, a positive correlation was found between n-6 PUFAs and synovitis. However, an inverse association has been noted between n-3 PUFAs and cartilage loss in the patellofemoral joint.
A diet high in n-3 was associated with reduced progression of osteoarthritis. In a mouse model, 12 weeks of soybean oil and flaxseed oil supplementation resulted in greater cartilage thickening and decreased tumor necrosis factor α (TNF-α) levels in both chondrocytes and serum. In human studies, treatment with docosahexaenoic acid (DHA) resulted in decreased apoptosis and increased chondrocyte proliferation, reflecting increased autophagy and cartilage thickening.
Omega-3 PUFAs, osteoarthritis and related diseases
Cardiovascular morbidity is inversely related to aerobic exercise, which often has a negative effect on osteoarthritis. Previous studies have shown that people taking eicosapentaenoic acid (EPA) and DHA supplements had significantly reduced triglyceride levels, neutrophil counts, and white blood cell (WBC) counts, suggesting that omega-3 supplements may mitigate adverse musculoskeletal events and preserve physical function.
Maintaining muscle mass is key to maintaining physical activity levels and reducing the risk of associated diseases. In this regard, omega-3 supplements have been shown to cause indirect benefits through muscle recovery after exercise. In a previous study of older adults aged 60 to 85 years, omega-3 supplements derived from fish oil resulted in increases in hand grip strength and quadriceps muscle size.
Delayed onset muscle soreness (DOMS) involves decreased joint range of motion, muscle strength, and muscle swelling. One study found that EPA and DHA supplementation resulted in significant improvements in joint range of motion, decreased muscle pain, and increased maximum voluntary contraction.
Research consistently shows that omega-3 PUFAs reduce cartilage degradation and levels of inflammatory biomarkers, thereby slowing the progression of osteoarthritis. Omega-3 PUFAs also provide indirect benefits by improving muscle tissue recovery after exercise. More clinical trials are needed in the future to better understand standardized omega-3 supplementation for modulating osteoarthritis.
It is important to note that there is no definitive evidence regarding the optimal dosage of omega-3 PUFA supplements, nor the ratio of DHA to EPA and n-6/n-3. Moreover, most studies have been conducted on animal models rather than humans. The source of omega-3 PUFAs may also influence potential results by affecting their bioavailability.