Have you ever experienced ankle, knee, shoulder or hip pain?
Most people over 35 can probably tell you they have suffered from some type of joint pain in their life. Painful joints can severely affect an individual's quality of life and mobility. In the elderly, joint pain is undoubtedly the number one cause of losing the possibility of independent living.
The most common reasons for joint pain are the well-known diseases of rheumatoid arthritis and osteoarthritis. Many active individuals and certainly most competitive athletes must deal with joint pain or disability on almost a constant basis. Maintaining or rebuilding joint tissue is crucial for individuals of all ages if they are to enjoy long lasting freedom from joint pain.
Composition of joint tissue Ligaments and Cartilage are forms of dense connective tissue which provide both stability and cushioning to joints. The macromolecules of which dense connective tissue is composed includes proteins (collagen and elastin) and proteoglycans. Proteoglycans are composed of a protein core with glycosaminoglycans (GAGs) attached. The synthesis of these macromolecules is well studied and known to require a number of important micronutrients.(1) Collagen is the most abundant protein in the body and is a component of all types of connective tissue. Since connective tissue is pervasive in the body, producing and maintaining healthy collagen is tantamount to maintaining health. Collagen has a triple helix configuration which gives it tremendous strength. This special biochemical configuration is highly dependent on the incorporation of the amino acid proline during the synthesis of collagen.
The production of normal proline requires vitamin C.(2) Some of the earliest manifestations of scurvy, the vitamin C deficiency disease, are weakened connective tissue, i.e. easy bleeding of the gums. Although scurvy is considered rare in the developed world, inadequate intakes of vitamin C could still manifest in weakened connective tissue. Weakened connective tissue could allow joints to be vulnerable to injury. GAGs are a major component of cartilage, hence smooth operation of joints is highly dependent on healthy GAGs.(3)
Within cartilage there are two main types of GAGs, chondroitin-4-sulphate and chondroitin-6-sulphate. GAGs are composed of repeat disaccharide (two) units. These units are composed of sugar amine compounds (i.e. glucosamine or galactosamine) bound together as a polymer.(4) All GAGs also contain sulfate ester moieties, i.e. the element sulfur is required for normal GAG synthesis. In fact, two of the studies actually showed that NSAIDs can interfere with the normal production of GAGs in cartilage.(5,6) Presumably joint destruction will not occur with NSAIDs unless "high," chronic use of NSAIDs is being employed. At this time, it is not clear what is meant by a"high" dose or for how long someone can ingest NSAIDs before joint destruction begins.
People with rheumatoid or osteo-arthritis and athletes who freely use NSAIDs to continue their athletic endeavors despite joint pain, would undoubtedly be the individuals at greatest risk for NSAIDs caused joint destruction. Athletes are also vulnerable to kidney problems, maybe even kidney failure, with high NSAID use combined with heavy sweating during workouts. Prostaglandins, the compounds whose synthesis is blocked by NSAIDs, are extremely important for normal kidney function. In order for the kidneys to filter the blood properly and help maintain normal water balance they must receive plenty of blood. Prostaglandins play a role in dilating kidney blood vessels and thereby ensuring adequate blood flow to the kidneys. Less blood to the kidneys combined with high fluid loss during sweating could be a deadly combination.
For severe joint pain, intra-articular (right into the painful joint) corticosteroid injections will often be given. Corticosteroids are very effective anti-inflammatory agents, but the injections themselves are often painful and corticosteroids can also lead to joint damage. Corticosteroids, in high doses, leads to connective tissue degradation. You would expect that collagen breakdown would be increased. How many injections are needed before joint destruction can occur is unclear. The question remains, is short term pain relief worth the possibility of a joint that may forever be weakened?
It may be possible, even after use of steroidal and non-steroidal anti-inflammatory agents that appropriate nutrient intake (maybe supplemental) and exercise rehabilitation could return weakened, damaged joint connective tissue back to full strength.
Nutrient supplements There are two general approaches to treating joint pain; blocking the inflammatory response or enhancing healthy connective tissue regeneration (i.e chondroprotective agents). Natural products may be used to treat joint pain because they act as; 1) macromolecule synthesis co-factors, i.e. micronutrients, 2) precursor compounds which actually become part of connective tissue macromolecules, or 3) natural anti-inflammatory agents.
Although a number of botanical medicines have been well studied for their anti-inflammatory effects, this article will focus on nutrients which are considered chondroprotective agents in that they are thought to work by one of the first two mechanisms. Numerous animal and human studies have reported beneficial results in the treatment of osteoarthritis using glucosamine sulfate.(9) In a number of these studies the effectiveness of glucosamine sulfate supplementation has specifically been compared to NSAIDs in patients with osteoarthritis. A Russian study found that the benefits of glucosamine sulfate were evident even one month after stopping supplementation.(10)
The most compelling evidence for the connective tissue building actions of glucosamine sulfate arises from cartilage tissue biopsies from patients with osteoarthritis.(11) One group of patients was treated with glucosamine sulfate while the other group was treated with placebo. Microscopically, the cartilage from patients treated with glucosamine sulfate had the appearance of healthy, not damaged cartilage. In a number of clinical trials with osteoarthritis patients, SAM performed at least as well as NSAIDs, and often with fewer side effects.(12.13) Most importantly, SAM may have connective tissue rebuilding effects, evidenced by the maintenance of benefits one month after stopping the supplement.(114) SAM has also been found to stimulate production of GAGs which, as we have seen, are the building blocks of connective tissue. (SAM is a special form of the sulfur containing amino acid methionine called S-adenosylmethionine.)
Minerals shown to be important in producing strong connective tissue are copper, zinc, manganese, and boron.
The best way to obtain a complement of these minerals is to add fresh nuts, seeds, and non-citrus fruits to the diet. For repair, such as with osteoarthritis or following joint injury, supplementation in a synergistic form may be warranted
Exercise for healthy joints Healthy connective tissue needs to be both strong and supple. Regular exercise is a key to achieving both. Resistance exercises (strength training) appear to be the best form of physical activity to stimulate new growth and correctly align the collagen fibers in newly forming connective tissue.(15,16) This means that joints need to be moving against some resistance, either using weights or working against body weight as in push-ups. These exercises are best done slowly and when the joint is free of pain.
The approach to take for strengthening a joint which has been injured or is arthritic should begin with isometric exercises. These are resistance exercises whereby the muscles surrounding the affected joint is contracted, but there is no movement at the joint. This type of exercise would be referred to as a "holding" exercise. Specifically, correctly executed (i.e. with proper biomechanics) yoga poses are an excellent form of isometric exercises. Since these types of resistances exercises do not require movement of a painful joint, they can be started as long as the joint is stable. Once joint movement becomes pain-free, adding in isotonic resistance exercises is important.
Strengthening the joint (and all the connective tissue maintaining the joint) within its full range of motion is extremely important to return the joint to full functionality. Flexibility or stretching exercises are tantamount to maintaining and rebuilding supple connective tissue.(17) Stretching of the connective tissue around the affected joint should begin as soon as the joint is relatively pain and inflammation free. Stretching exercises should include the affected joint but also the unaffected paired joint and always be within the limits of pain.
Please see reference (17) for more details on how to properly undertake a stretching program.
Summary
Maintaining joint health is a matter of paying attention to diet and exercise (not very original!).
In the diet a sufficient intake of minerals and vitamin C is ultimately important for synthesis of healthy connective tissue. Often supplementation is needed.
Adding in two aspects of exercise which are less publicized (strengthening and stretching) than aerobic exercise, are the key to maintaining joint health, i.e. prevent future injury. The only effect an individual is achieving with NSAIDs is anti-inflammatory. This means that treating affected joints with NSAIDs is simply symptomatic relief. Although the cause of joint pain appears to be chemicals involved in the inflammatory response, joint inflammation is a response to damaged connective tissue. Therefore the logical, comprehensive treatment for joint pain is to deal with the underlying cause of damaged connective tissue.
References
(1)Tinker D, Rucker R. Role of selected nutrients in synthesis, accumulation, and chemical modification of connective tissue proteins. Physiol Rev 65(3):607-653, 1985.
(2)Bates CJ, Levene CI. The effect of ascorbic acid deficiency on the glycosaminoglycans and glycoproteins in connective tissue. Bibl Nutr Dieta 13:131-143, 1969.
(3.) Comper WD, Laurent TC. Physiological function of connective tissue polysaccharides. Physiol Rev 58:255-315, 1987.
(4.) Hascall VC, Hascall GK. Proteoglycans. In: Cell Biology of Extracellular Matrix, edited by Hay ED. New York, Plenum, 1981, p. 39-63.
(5.) Palmoski MJ, Brandt KD. Effects of some nonsteroidal antiinflammatory drugs on proteoglycan metabolism and organization in canine articular cartilage. Arthrit Rheum 23(9):1010-1019, 1980.
(6.) Brandt KD. Effects of nonsteroidal anti-inflammatory drugs on chondrocyte metabolism in Vitro and in Vivo. Am J Med 83(suppl 5A):30-34, 1987.
(9.) Sheild MJ. Anti-inflammatory drugs and their effects on cartilage synthesis and renal function. European J Rheumatol Inflam 13:716, 1993.
(10.) Vajaradul Y. Double-blind clinical evlauation of intra-articular glucosamine in outpatients with gonarthrosis. Clin Ther 3:336-343, 1981. (20.) Setnikar I, Cereda R, Pacini MA, Revel L. Antireactive properties of glucosamine sulfate. Arzneim-Forsch 41:542-545, 1991b.
(11.) Drovanti A, Biganamini AA, Rovati AL. Therapeutic activity of oral glucosamine sulfate in osteoarthrosis: a placebo-controlled double-blind investigation. Clin Ther 3(4):260-272, 1980.
(12.) Vetter G. Double-blind comparative clinical trial with S-adenosylmethionine and indomethacin in the treatment of osteoarthritis. Am J Med 83(suppl 5A): 78-80, 1987.
(13.) Muller-Fassbender H. Double-blind clinical trial of S-adenosylmethionine versus ibuprofen in the treatment of osteoarthritis. Am J Med 83(suppl 5A):81-83, 1987.
(14.) Maccagno A, Di Giorgio EE, Caston OL, Sagasta CL. Double-blind controlled clinical trial of oral S-adenosylmethionine versus piroxicam in knee osteoarthritis. Am J Med 83(suppl 5A):72-53, 1987.
(15.) Maffulli N, King JB. Effects of physical activity on some components of the skeletal system. Sports Med 13(6):393-407, 1992.
(16.) Stone MH. Implications for connective tissue and bone alterations resulting from resistance exercise training. Med Sci Sports Exerc 20(5):S162-S168, 1988.
(17.) MacIntosh A. Stretching: a therapeutic exercise. Townsend Lett Apr 97:32-34.
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Disclaimer: This article is not meant to replace consultation with trained health care professionals. The publisher and author are not responsible for any adverse consequences of effects resulting from the use of any of the information or suggestions contained in this article. All research has been done in good faith, using recognized sources.
