The definition of nutrition has changed considerably through time. The modern purpose of nutrition includes digestion, assimilation, and nutrient metabolism. Now movement, fitness, and the balance of all the above are needed to sustain a healthy lifestyle and promote development through the life stages. Furthermore, movement balances the calories we intake and the energy we utilize while performing physical activity. Exercise can also stimulate muscle hypertrophy, decrease the risk of falls in the elderly and increase our quality of life. Since our bodily systems are so carefully intertwined, our skeletal muscle system depends on our joints and their function to create this movement. Can nutrition reverse joint degradation? Is supplementation needed for joint health?

Joints and movement

Our articular cartilage has the essential purpose of providing a smooth and lubricated surface that lowers the frictional coefficient between our bones. Nevertheless, articular cartilage lacks blood vessels, lymphatics, and nerves, making it difficult to explain the pain related to DJD. This is why degenerative joint disease (DJD) is one of the leading causes of pain and dysfunction.

So, what is cartilage comprised of? Joint tissue composition is a mixture of water, collagen, and proteoglycans. Also, to a lesser extent, this tissue contains chondrocytes, non-collagenous proteins, and glycoproteins. These components create a dense extracellular matrix (ECM) that retains moisture to maintain joint tissue’s mechanical function.

Chondrocytes, collagen, and inflammation

Chondrocytes are critical for the metabolism, maintenance, repair, and development of our ECM. Indeed, these cells have the capacity to synthesize matrix components, including proteins and glycosaminoglycan chains.  

Nevertheless, pro-inflammatory cytokines and mechanical wear and tear can affect chondrocytes’ metabolic activity. 

• Collagen 

On the other hand, collagen is the most abundant component of ECM. Indeed, it comprises about 60% of the dry weight of cartilage being approximately 90-95% of type II collagen. Furthermore, collagen contains a region of 3 polypeptide chains made of glycine and proline, with hydroxyproline. These amino acids provide stability through their hydrogen bonds and the length of the molecule.

Is supplementation needed to restore joint function?

Connective tissue has a very particular composition, and at the same time, it is heavily affected by the mechanical friction of our bones and inflammation. Furthermore, chondrocytes depend on the matrix, and the matrix depends on the chondrocyte’s metabolism; it is like a vicious circle. Nevertheless, studies show that collagen damage might be the culprit of joint disorders, making it paramount to stop its degradation. 

Proline and Lysine

In 2018, Paz Lugo et al. noted that cartilage needed large amounts of glycine, proline, and lysine to promote collagen synthesis and reverse osteoarthritis. Indeed, their study showed that low concentrations of proline and lysine enhanced the synthesis of type II collagen at low concentrations. Nevertheless, this study concluded increasing dietary glycine is the best strategy to improve collagen synthesis and thus prevent osteoarthritis. 

Curcumin and Osteoarthritis

The use of curcumin to treat osteoarthritis has been studied to a vast degree. Indeed, inflammatory cytokines play a critical role in connective tissue deterioration; curcumin’s anti-inflammatory effects are essential to modulating this response. The practical components of Z. officinale: gingerols, shogaols, zingerone, and paradol, and ginger itself exert anti-inflammatory effects by inhibiting COX-1 and COX-2, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and 5-lipoxygenase (5-LOX).

• Curcuma longa

The Journal of Medicinal Food published a systematic review and meta-analysis of RCTs to determine the efficacy of turmeric extracts for alleviating symptoms of osteoarthritis. Furthermore, this meta-analysis concluded that the supplementation of turmeric extract (1000mg/day) has a solid efficacy in treating arthritis pain.

In addition, Heidari-Beni et al. compared the anti-inflammatory effect of curcumin mixed with black pepper and ginger with Naproxen. Their study concluded that Naproxen and the herbal mixture significantly decreased prostaglandin E2 in patients with knee osteoarthritis after four weeks. Furthermore, there was no significant difference between the group taking Naproxen and the one supplemented with the herbal extract.

Conclusion:

Joint tissue is a highly specialized component of our body, which determines how we move and, therefore, can forge our quality of living. Movement is paramount for our healthy development, and so is the maintenance, repair, and synthesis of our cartilage. 

Supplementation plays a vital role in decreasing joint pain, promoting collagen fiber synthesis, and stopping inflammation. Nutrients and amino acids, such as proline, lysine, and curcumin, play a critical role in reversing joint degeneration. Indeed, the anti-inflammatory effects of curcumin can modulate pro-inflammatory reactions and therefore prevent joint disease.- Ana Paola Rodríguez Arciniega, MS

Bibliography:

Sophia Fox, A. J., Bedi, A., & Rodeo, S. A. (2009). The basic science of articular cartilage: structure, composition, and function. Sports Health, 1(6), 461–468. doi.org/10.1177/1941738109350438

de Paz-Lugo, P., Lupiáñez, J. A., & Meléndez-Hevia, E. (2018). High glycine concentration increases collagen synthesis by articular chondrocytes in vitro: acute glycine deficiency could be an important cause of osteoarthritis. Amino acids, 50(10), 1357–1365. doi.org/10.1007/s00726-018-2611-x

Daily, J. W., Yang, M., & Park, S. (2016). Efficacy of Turmeric Extracts and Curcumin for Alleviating the Symptoms of Joint Arthritis: A Systematic Review and Meta-Analysis of Randomized Clinical Trials. Journal of medicinal food, 19(8), 717–729. doi.org/10.1089/jmf.2016.3705

Heidari-Beni, M., Moravejolahkami, A. R., Gorgian, P., Askari, G., Tarrahi, M. J., & Bahreini-Esfahani, N. (2020). The herbal formulation “turmeric extract, black pepper, and ginger” versus Naproxen for chronic knee osteoarthritis: A randomized, double-blind, controlled clinical trial. Phytotherapy research: PTR, 34(8), 2067–2073. doi.org/10.1002/ptr.6671