Joint supplements help reduce the soreness, stiffness, pain, and other problems that can affect joints as a result of overuse, injury, aging, and illness. This glossary page defines key terms in the context of joint health and supplementation.
Arthritis
A catch-all term referring to disorders of the joints. Arthritis is the leading cause of disability in the U.S and its most common symptoms involve joint swelling, stiffness, pain, and reduced range of motion, any of which can be temporary or cause permanent, visible changes to the body. Over 100 types of arthritis exist – although the most common are osteoarthritis and rheumatoid (autoimmune) arthritis.
Bone Density
Also known as bone mineral density (BMD), this term describes the amount of bone minerals—particularly calcium and phosphorus—in a bone. Low bone density correlates with an increased risk of fracture.
Collagen
The main structural protein found in the human body, present in bones, tendons, cartilage, and other tissues.
Cartilage
Cushion-like tissue found in joints and bones known for its tough and elastic properties. The lack of blood vessels in cartilage means that it has difficulty healing.
Cytokine
Protein molecules such as interferon and interleukin that are secreted by immune cells and control the body’s immune response. Specific cytokines can promote the proliferation (growth and division) of specific immune cells, enhance immune cell activity, promote or reduce inflammation, and control over aspects of the immune system.
Chondroprotection
This refers to the ability of certain compounds to delay joint space narrowing seen in arthritis and protect chondrocytes, which are cells making up cartilage. Some forms of arthritis are treated with chondroprotective agents.
Glycosaminoglycan
Compounds serving as the main structural component of cartilage and are known for their highly viscous nature that helps lubricate the joints. Chondroitin sulfate is a glycosaminoglycan popularly used as a supplement to improve joint health.
Inflammation
Inflammation is an instinctive immune response to harmful stimuli and stress that is meant to remove “bad” tissue or substances and initiate tissue repair. Heat, redness, swelling, pain, and reduced function are common signs of inflammation. Insufficient inflammation can lead to gradual tissue destruction, while excessive inflammation can cause unnecessarily damage healthy cells. Inflammation plays a central role in joint disorders.
Inflammatory marker
Inflammatory markers are molecules indicating the presence of an inflammatory response, be it normal or harmful. Common markers include phospholipase, lipooxygenase, leukotrienes, interleukins, prostaglandins, platelet activating factor, tumor necrosis factor, and nitric oxide.
Joint Narrowing
Decreasing of the space between joints due to the loss of cartilage. Narrowing takes place gradually due to everyday wear and tear but can be significantly sped up as a result of joint conditions such as arthritis.
Joint Stiffness
A feeling of limited motion of the joints that is caused chiefly by swelling and inflammation. It is one of the key symptoms of arthritis.
Ligament
A ligament is a band of fibrous tissue that binds one bone to another. A tear of the knee’s anterior cruciate ligament, or ACL for short, is one of the most common sports injuries.
Nuclear Factor Kappa Beta (nF-κβ) Pathway
The body’s major inflammation-promoting signaling system, which is why it is considered the prime target for anti-inflammatory medicine.
Osteoarthritis
The most common chronic joint condition, osteoarthritis is a degenerative disorder characterized by joint stiffness and pain. It typically occurs when too much cartilage between joints is broken down due to injury, excess weight, overuse, or genetic factors.
Osteoblast
Osteoblasts are not only the main cells found in bones, but also help in their formation.
Osteoclast
An osteoclast is a type of cell whose function is to break down bone and cartilage via a process known as bone resorption. It is responsible for maintaining, remodeling, and repairing bones.
Oxidative Stress
Not to be confused with physiologic stress, oxidative stress is a result of an overflow of free radicals, the byproducts of biological reactions that can damage cells, including those making up joints. Compounds known as antioxidants have been shown to counteract the negative consequences of oxidative stress.
Rheumatoid Arthritis
Rheumatoid arthritis is an inflammatory disease that primarily affects the joints, though it can also damage the skin, eyes, heart, and blood vessels. It is considered an autoimmune disorder because the immune system attacks its own healthy tissues. Rheumatoid arthritis is capable of deteriorating the lining of joints, which can result in bone erosion and joint deformity.
Tendon
Also called sinew, a tendon is a band of fibrous tissue binding muscle to bone. It is made up of a sturdy collection of collagen that is able to withstand a lot of tension.
