Osteoarthritis (OA) is a chronic disease of the joints, especially the weight-bearing joints that develops when the linings of joints degenerate, leading to lipping and spurring of bone, pain, and decreased mobility and function.
OA is a universal consequence of aging among animals with a bony skeleton. Many factors contribute to the development of OA; the disease is primarily associated with aging and injury and was once called “wear-and-tear” arthritis. OA may occur secondary to many other conditions. However, in most cases, the true cause of OA is unknown.
What are the symptoms of osteoarthritis?
The onset of OA is gradual and most often affects the hips, knees, fingers, and spine, although other joints also may be involved. Pain is the main symptom, which usually worsens with exercise and is relieved by rest. Morning stiffness is also common and diminishes with movement. As OA progresses, joint motion is lost, and tenderness and grating sensations may develop. OA of the spine may lead to shooting pains down the arms or legs.
Dietary changes that may be helpful for osteoarthritis
In the 1950s through the 1970s, Dr. Max Warmbrand used a diet free of meat, poultry, dairy, chemicals, sugar, eggs, and processed foods for people with rheumatoid arthritis and OA, anecdotally claiming significant success.1 He reported that clinical results took at least six months to develop. The Warmbrand diet has never been properly tested in clinical research. Moreover, although the diet is healthful and might reduce the risk of being diagnosed with many other diseases, it is difficult for most people to follow. This difficulty, plus the lack of published research, leads many doctors who are aware of the Warmbrand diet to use it only if other approaches have failed.
Solanine is a substance found in nightshade plants, including tomatoes, white potatoes, all peppers (except black pepper), and eggplant. In theory, if not destroyed in the intestine, solanine may be toxic. One horticulturist hypothesized that some people might not be able to destroy solanine in the gut, leading to solanine absorption and resulting in OA. This theory has not been proven. However, eliminating solanine from the diet has been reported to bring relief to some arthritis sufferers in preliminary research.2 3 In a survey of people avoiding nightshade plants, 28% claimed to have a “marked positive response” and another 44% a “positive response.” Researchers have never put this diet to a strict clinical test; however, the treatment continues to be used by some doctors with patients who have OA. As with the Warmbrand diet, proponents claim exclusion of solanine requires up to six months before potential effects may be seen. Totally eliminating tomatoes and peppers requires complex dietary changes for most people. In addition, even proponents of the diet acknowledge that many arthritis sufferers are not helped by using this approach. Therefore, long-term trial avoidance of solanine-containing foods may be appropriate only for people with OA who have not responded to other natural treatments.
Most of the studies linking allergies to joint disease have focused on rheumatoid arthritis, although mention of what was called “rheumatism” in older reports (some of which may have been OA) suggests a possible link between food reactions and aggravations of OA symptoms.4 If other therapies are unsuccessful in relieving symptoms, people with OA might choose to discuss food allergy identification and elimination with a physician.
Lifestyle changes that may be helpful for osteoarthritis
Obesity increases the risk of OA developing in weight-bearing joints, and weight loss in women is associated with reduced risk for developing OA.5 67
Weight loss is also thought to reduce the pain of existing OA.
Nutritional supplements that may be helpful for osteoarthritis
Glucosamine sulfate (GS), a nutrient derived from seashells, is a building block needed for the synthesis and repair of joint cartilage. GS supplementation has significantly reduced symptoms of OA in uncontrolled8 9 and single-blind trials.10 11 Many double-blind trials have also reported efficacy.12 13 14 15 1617 has reported no effect of GS on OA symptoms. While most research trials use 500 mg GS taken three times per day, results of a three-year, double-blind trial indicate that 1,500 mg taken once per day produces significant reduction of symptoms and halts degenerative changes seen by X-ray examination.18 GS does not cure people with osteoarthritis, and they may need to take the supplement for the rest of their lives in order to maintain benefits. Fortunately, GS appears to be virtually free of side effects, even after three or more years of supplementation. Benefits from GS generally become evident after three to eight weeks of treatment. Only one published trial
Only one trial has evaluated another form of glucosamine as a single remedy for OA.19 This trial found only minor benefits from 1,500 mg per day of glucosamine hydrochloride (GH) for eight weeks in people with osteoarthritis of the knee; these people were also taking up to 4,000 mg per day of acetaminophen for pain relief. To more fairly evaluate the effects of GH, future research should exclude people taking pain-relieving medication. Another form of glucosamine sometimes found in combination formulas, N-acetyl-glucosamine (NAG), has not been studied in people with osteoarthritis.
Chondroitin sulfate (CS) is a major component of the lining of joints. The structure of CS includes molecules related to glucosamine sulfate. CS levels have been reported to be reduced in joint cartilage affected by OA. Possibly as a result, CS supplementation may help restore joint function in people with OA.20 On the basis of preliminary evidence, researchers had believed that oral CS was not absorbed in humans;21 as a result, early double-blind CS research was done mostly by giving injections.22 23 This research documented clinical benefits from CS injections. It now appears, however, that a significant amount of CS is absorbable in humans,24 though dissolving CS in water leads to better absorption than swallowing whole pills.25
Strong clinical evidence now supports the use of oral CS supplements for OA. Many double-blind trials have shown that CS supplementation consistently reduces pain, increases joint mobility, and/or shows evidence (including X-ray changes) of healing within joints of people with OA.26 27 28 29 30 31 32 33 34 3536 Reduction in symptoms typically occurs within several months. Most trials have used 400 mg of CS taken two to three times per day. One trial found that taking the full daily amount (1,200 mg) at one time was as effective as taking 400 mg three times per day.
S-adenosyl methionine (SAMe) possesses anti-inflammatory, pain-relieving, and tissue-healing properties that may help protect the health of joints,37 38 though the primary way in which SAMe reduces OA symptoms is not known. A very large, though uncontrolled, trial (meaning that there was no comparison with placebo) demonstrated “very good” or “good” clinical effect of SAMe in 71% of over 20,000 OA sufferers.39 In addition to this preliminary research, many double-blind trials have shown that SAMe reduces pain, stiffness, and swelling better than placebo and equal to drugs such as ibuprofen and naproxen in people with OA.40 41 42 43 44 45 46 47 These double-blind trials all used 1,200 mg of SAMe per day.
Lower amounts of oral SAMe have also produced reductions in the severity of OA symptoms in preliminary clinical trials. A two-year, uncontrolled trial showed significant improvement of symptoms after two weeks at 600 mg SAMe daily, followed by 400 mg daily thereafter.48 This amount was also used in a double-blind trial, but participants first received five days of intravenous SAMe.49 A review of the clinical trials on SAMe concluded that its efficacy against OA was similar to that of conventional drugs but that patients tolerated it better.50
People who have OA and eat large amounts of antioxidants in food have been reported to exhibit a much slower rate of joint deterioration, particularly in the knees, compared with people eating foods containing lower amounts of antioxidants.51 Of the individual antioxidants, only vitamin E has been studied as a supplement in controlled trials. Vitamin E supplementation has reduced symptoms of OA in both single-blind52 and double-blind research.53 54 In these trials, 400 to 1,600 IU of vitamin E per day was used. Clinical effects were obtained within several weeks. However, in a six-month double-blind study of patients with osteoarthritis of the knee, 500 IU per day of vitamin E was no more effective than a placebo.55
In the 1940s and 1950s, one doctor reported that supplemental niacinamide (a form of vitamin B3) increased joint mobility, improved muscle strength, and decreased fatigue in people with OA.56 57 58 In the 1990s, a double-blind trial confirmed a reduction in symptoms from niacinamide within 12 weeks of beginning supplementation.59 Although amounts used have varied from trial to trial, many doctors recommend 250 to 500 mg of niacinamide four or more times per day (with the higher amounts reserved for people with more advanced arthritis). The mechanism by which niacinamide reduces symptoms is not known.
The effects of New Zealand green-lipped mussel supplements have been studied in people with OA. In a preliminary trial, either a lipid extract (210 mg per day) or a freeze-dried powder (1,150 mg per day) of green-lipped mussel reduced joint tenderness and morning stiffness, as well as improving overall function in most participants.60 In a double-blind trial, 45% of people with OA who took a green-lipped mussel extract (350 mg three times per day for three months) reportedly had improvements in pain and stiffness.61 Another double-blind trial reported excellent results from green-lipped mussel extract (2,100 mg per day for six months) for pain associated with arthritis of the knee.62 Side effects, such as stomach upset, gout, skin rashes, and one case of hepatitis have been reported in people taking certain New Zealand green-lipped mussel extracts.63
The therapeutic use of DMSO (dimethyl sulfoxide) is controversial because of safety concerns, but some preliminary research shows that diluted preparations of DMSO, applied directly to the skin, are anti-inflammatory and alleviate pain, including pain associated with OA.64 65 A recent double-blind trial found that a 25% concentration of DMSO in gel form relieved osteoarthritis pain significantly better than a placebo after three weeks.66 DMSO appears to reduce pain by inhibiting the transmission of pain messages by nerves67 rather than through a process of healing damaged joints. DMSO comes in different strengths and different degrees of purity; in addition, certain precautions must be taken when applying DMSO. For these reasons, DMSO should be used only with the supervision of a doctor.
According to a small double-blind trial, 2,250 mg per day of oral methylsulfonylmethane (MSM), a variant of DMSO, reduced OA pain after six weeks.68
Cetyl myristoleate (CMO) has been proposed to act as a joint “lubricant” and anti-inflammatory agent. In a double-blind trial, people with various types of arthritis who had failed to respond to non-steroidal anti-inflammatory drugs (NSAIDs) received CMO (540 mg per day orally for 30 days), while others received a placebo.69 These people also applied CMO or placebo topically, according to their perceived need. A statistically significant 63.5% of those using CMO improved, compared with only 14.5% of those using placebo.
Boron affects calcium metabolism, and a link between boron deficiency and arthritis has been suggested.70 Although people with OA have been reported to have lower stores of boron in their bones than people without the disease, other minerals also are deficient in the bones of people with OA.71 One double-blind trial found that 6 mg of boron per day, taken for two months, relieved symptoms of OA in five of ten people, compared with improvement in only one of the ten people assigned to placebo.72 This promising finding needs confirmation from larger trials.
The omega-3 fatty acids present in fish oil, EPA and DHA, have anti-inflammatory effects and have been studied primarily for rheumatoid arthritis, which involves significant inflammation. However, OA also includes some inflammation.73 In a 24-week controlled but preliminary trial studying people with OA, people taking EPA had “strikingly lower” pain scores than people who took placebo.74 However, in a double-blind trial by the same research group, supplementation with 10 ml of cod liver oil per day was no more effective than a placebo.75
Supplementation with D-phenylalanine (DPA), a synthetic variation of the amino acid, L-phenylalanine (LPA), has reduced chronic pain due to OA in a preliminary trial.76 In that study, participants took 250 mg three to four times per day, with pain relief beginning in four to five weeks. Other preliminary trials have confirmed the effect of DPA in chronic pain control,77 but a double-blind trial found no benefit.78 DPA inhibits the enzyme that breaks down some of the body’s natural painkillers, substances called enkephalins, which are similar to endorphins. An increase in the amount of enkephalins may explain the reported pain-relieving effect of DPA. If DPA is not available, a related product, D,L-phenylalanine (DLPA), may be substituted (1,500 to 2,000 mg per day). Phenylalanine should be taken between meals, because protein found in food may compete for uptake of phenylalanine into the brain, potentially reducing its effect.79
Several trials have suggested that people with OA may benefit from supplementation with bovine cartilage, which contains a mixture of protein and molecules related to chondroitin sulfate. In one preliminary trial, use of injected and topical bovine cartilage led to symptom relief in most people studied.80 A ten-year study confirmed improvement with long-term use of bovine cartilage.81 Optimal intake of bovine cartilage is not known.
Are there any side effects or interactions with osteoarthritis?
Refer to the individual supplement for information about any side effects or interactions.
Herbs that may be helpful for osteoarthritis
Several double-blind trials have shown that topical use of cayenne extract creams containing 0.025 to 0.075% capsaicin reduces pain and tenderness caused by OA.82 83 84 85 These creams are typically applied four times daily for two to four weeks, after which twice daily application may be sufficient.86 Products containing capsicum oleoresin rather than purified capsaicin may not be as effective.87
Willow has anti-inflammatory and pain-relieving properties. Although pain relief from willow supplementation may be slow in coming, it may last longer than pain relief from aspirin. One double-blind trial found that a product containing willow along with black cohosh, guaiac (Guaiacum officinale, G. sanctum), sarsaparilla, and aspen (Populus spp.) bark effectively reduced OA pain compared to placebo.88 Another trial found that 1,360 mg of willow bark extract per day (delivering 240 mg of salicin) was somewhat effective in treating pain associated with knee and/or hip OA.89
Stinging nettle has historically been used for joint pain. Topical application with the intent of causing stings to relieve joint pain has been assessed in preliminary90 and double-blind91 trials. The results found intentional nettle stings to be safe and effective for relieving the pain of OA. The only reported adverse effect is a sometimes painful or numbing rash that lasts 6 to 24 hours.
Ginger has historically been used for arthritis and rheumatism. A preliminary trial reported relief in pain and swelling among people with arthritis who used powdered ginger supplements92 More recently, a double-blind trial found ginger extract (170 mg three times a day for three weeks) to be slightly more effective than placebo at relieving pain in people with OA of the hip or knee.93 In another double-blind study, a concentrated extract of ginger, taken in the amount of 255 mg twice daily for six weeks, was significantly more effective than a placebo, as determined by the degree of pain relief and overall improvement.94
In a preliminary trial, supplementation with 500 mg of a concentrated extract (3.5% guggulsterones) of Commiphora mukul (guggul) three times per day for one month resulted in a significant improvement in symptoms in people with osteoarthritis of the knee.95 Double-blind trials are needed to rule out the possibility of a placebo effect.
More recently, purified extracts of bovine cartilage containing chondroitin sulfate have been found to benefit people with osteoarthritis.96 97
In a double-blind study, collagen hydrolysate was compared with gelatin and egg protein as a treatment for osteoarthritis of the hip and/or knee. When subjects took 10 grams per day either of gelatin or collagen hydrolysate for two months, they reported significantly more pain relief than when they took a similar amount of egg protein.98 More research is needed to confirm the benefits of gelatin or collagen hydrolysate in osteoarthritis.
Devil’s claw extract was found in one clinical trial to reduce pain associated with OA as effectively as the slow-acting analgesic/cartilage-protective drug diacerhein.99 The amount of devil’s claw used in the trial was 2,610 mg per day. The results of this trial are somewhat suspect, however, as both devil’s claw and diacerhein are slow-acting and there was no placebo group included for comparison.
Boswellia has anti-inflammatory properties that have been compared to those of the NSAIDs used by many for inflammatory conditions.100 Clinical trials in humans using boswellia alone are lacking. However, one clinical trial found that a combination of boswellia, ashwagandha, turmeric, and zinc effectively treated pain and stiffness associated with OA but did not improve joint health, according to X-rays of the affected joint.101 Unlike NSAIDs, however, long-term use of boswellia does not lead to irritation or ulceration of the stomach.
Horsetail is rich in silicon, a trace mineral that plays a role in making and maintaining connective tissue. Practitioners of traditional herbal medicine believe that the anti-arthritis action of horsetail is due largely to its silicon content. The efficacy of this herb for OA has not yet been evaluated in controlled clinical trials.
According to arthritis research, saponins found in the herb yucca appear to block the release of toxins from the intestines that inhibit normal formation of cartilage. A preliminary, double-blind trial found that yucca might reduce symptoms of OA.102 Only limited evidence currently supports the use of yucca for people with OA.
Cat’s claw has been used traditionally for OA. In a double-blind trial, 100 mg per day of a freeze-dried preparation of cat's claw taken for four weeks was significantly more effective than a placebo at relieving pain and improving the overall condition.103
Meadowsweet was historically used for a wide variety of conditions, including treating complaints of the joints and muscles.104 The herb contains salicylates, chemicals related to aspirin, that may account for its reputed ability to relieve the pain of OA.
Colchicine is a remedy derived from autumn crocus (Colchicum autumnale) that may be helpful for chronic back pain caused by herniated discs. A review of research reports that colchicine can relieve pain, muscle spasm, and weakness associated with disc disease.105 The author of this study suggests that colchicine produces dramatic improvement in about 40% of cases of disc disease. In most studies, colchicine has been given intravenously.106 However, oral colchicine may also be moderately effective for OA. A physician expert in the use of herbal medicine should be consulted for the administration of colchicine.
Are there any side effects or interactions with osteoarthritis?
Refer to the individual herb for information about any side effects or interactions.
Holistic approaches that may be helpful for osteoarthritis
Several clinical trials have examined the efficacy of acupuncture for OA, with mixed results. Some trials found acupuncture treatment to be no more effective than either placebo107 or sham acupuncture108 at relieving OA pain. Other trials have demonstrated a significant effect of acupuncture on the relief of OA pain compared to placebo.109 110 A well-designed trial found that acupuncture treatments (twice weekly for eight weeks) significantly improved pain and disability in people with OA of the knee compared to no treatment.111 When the group receiving no treatment was switched to acupuncture treatments, they experienced similar improvements.
In a controlled trial, a combination of manual physical therapy (by a qualified physical therapist) and supervised exercise significantly improved walking distance and pain in a group of people with OA of the knee.112 The therapeutic regimen consisted of manual therapy to the knee, low back, hip, and ankle as necessary, as well as a standardized knee-exercise program performed at home and in the clinic. The treatments were given twice weekly at the clinic for four weeks.