Natural treatments for osteoarthritis

• PRINCIPAL PROPOSED NATURAL TREATMENTS:

• OTHER PROPOSED NATURAL TREATMENTS:
• PROBABLY INEFFECTIVE TREATMENTS: Mesoglycan, vitamin E

DEFINITION: Treatment of damage to joint cartilage.

Introduction

In osteoarthritis, the cartilage in joints has become damaged, disrupting the smooth gliding motion of the joint surfaces. The result is pain, swelling, and deformity. The pain of osteoarthritis typically increases with joint use and improves at rest. Although X-rays can find evidence of arthritis, the level of pain and stiffness experienced by people does not match the extent of injury noticed on X-rays.

Many theories exist about the causes of osteoarthritis, but no one knows what causes the disease. Osteoarthritis is often described as wear-and-tear arthritis, but evidence suggests that this simple explanation is incorrect. For example, osteoarthritis frequently develops in many joints at the same time, often symmetrically on both sides of the body, even when there is no reason to believe that equal amounts of wear and tear are present. Another intriguing finding is that osteoarthritis of the knee is commonly, and mysteriously, associated with osteoarthritis of the hand. These factors, and others, have led to the suggestion that osteoarthritis may be a body-wide disease of the cartilage.

During one’s lifetime, cartilage is constantly being turned over by a balance of forces that both break down and rebuild it. One prevailing theory suggests that osteoarthritis may represent a situation in which the degrading forces become chaotic. Some of the proposed natural treatments for osteoarthritis described here may inhibit enzymes that damage cartilage.

When the cartilage damage in osteoarthritis begins, the body responds by building new cartilage. For several years, this compensating effort can keep the joint functioning well. Some natural treatments work by assisting the body in repairing cartilage. Eventually, however, building forces cannot keep up with destructive ones, and what develops is end-stage osteoarthritis. This is the familiar picture of pain and impaired joint function.

The conventional medical treatment for osteoarthritis consists mainly of anti-inflammatory drugs, such as naproxen and Celebrex. The main problem with anti-inflammatory drugs is that they can cause ulcers. Another possible problem is that they may speed the progression of osteoarthritis by interfering with cartilage repair and by promoting cartilage destruction. In contrast, two of the treatments described here might slow the course of the disease, although this has not been proven.

Principal Proposed Natural Treatments

Several natural treatments for osteoarthritis have a meaningful, though not definitive, body of supporting evidence indicating that they can reduce pain and improve function. In addition, there is some evidence that glucosamine and chondroitin might offer additional benefits in helping to prevent progressive joint damage.

Glucosamine.Glucosamine is widely accepted as a treatment for mild to moderate osteoarthritis. It is said to stimulate cartilage cells in the joints to make proteoglycans and collagen—two proteins essential for proper joint function. Glucosamine may also help prevent collagen from breaking down. However, the supporting evidence that it works is somewhat inconsistent, with several studies failing to find benefits. Some evidence indicates that regular use can delay the progression of arthritis that occurs over time. Two types of studies have been performed—those that compared glucosamine with a placebo and those that compared it with standard medications.

In the placebo-controlled category, one of the best trials was a three-year double-blind study of 212 people with osteoarthritis of the knee. Participants receiving glucosamine showed reduced symptoms compared to those receiving the placebo. Benefits were also seen in other double-blind, placebo-controlled studies, enrolling more than eight hundred people and ranging from four weeks to three years. Even more double-blind studies enrolling more than four hundred people compared glucosamine with ibuprofen and found glucosamine just as effective as the drug.

Further studies have not shown benefit. In four studies involving almost five hundred people, using glucosamine failed to improve symptoms to any greater extent than the placebo. In a study involving 222 participants with hip osteoarthritis, two years of treatment with glucosamine was no better than the placebo at improving pain or function. Another study involving 147 women with osteoarthritis found glucosamine to be no more effective than home exercises over eighteen months. A third study evaluated the effects of stopping glucosamine after it was taken by participants for six months. In this double-blind trial of 137 people with osteoarthritis of the knee, participants who stopped using glucosamine and unknowingly took a placebo instead did no worse than those who stayed on glucosamine.

In a fourth, large study with 1,583 participants, neither glucosamine as glucosamine hydrochloride, nor glucosamine plus chondroitin was more effective than the placebo. Another study also failed to find benefits with glucosamine plus chondroitin. Finally, in a systematic review including randomized trials involving 3,803 people with hip or knee osteoarthritis, researchers found that neither glucosamine alone, chondroitin alone, nor the combination of glucosamine and chondroitin relieved pain. Most of the positive studies were funded by manufacturers of glucosamine products. Most of the studies performed by neutral researchers failed to find benefit. While the National Center for Complementary and Integrative Health (NCCIH) continued to find no benefit in the use of glucosamine and chondroitin for arthritis, the American College of Rheumatology and the Arthritis Foundation began conditionally recommending chondroitin in 2019, particularly for individuals with hand pain. A dose of chondroitin sulfate at 800 to 1,000 mg per day with glucosamine sulfate at 1,500 mg per day may be useful for some people.

Many popular glucosamine products contain methylsulfonylmethane (MSM). One study in India reported that both MSM and glucosamine improved arthritis symptoms compared with a placebo, but the combination of MSM and glucosamine was even more effective than either supplement separately.

Two studies reported that glucosamine can slow the progression of osteoarthritis. However, both of these studies were funded by a major glucosamine manufacturer. A three-year, double-blind, placebo-controlled study of 212 people found indications that glucosamine may protect joints from further damage. During the study, people given glucosamine experienced some improvement in pain and mobility, while those given a placebo worsened steadily. Furthermore, X-rays showed that glucosamine treatment prevented progressive damage to the knee joint. A separate three-year study enrolling 222 people found similar results. A follow-up analysis five years after the conclusion of the foregoing two studies found suggestive evidence that using glucosamine reduced the need for knee replacement surgery. However, the study involving 222 individuals with osteoarthritis of the hip failed to show any significant change in X-ray findings following two years of glucosamine treatment compared with the placebo.

Chondroitin sulfate. The supplement chondroitin is often combined with glucosamine. Several studies also have evaluated chondroitin used alone, with some positive results, both for improving symptoms and for slowing the progression of the disease. On balance, however, the evidence for chondroitin’s effectiveness for osteoarthritis remains inconsistent.

According to some double-blind, placebo-controlled studies, chondroitin may relieve symptoms of osteoarthritis. One study enrolled eighty-five people with osteoarthritis of the knee and followed them for six months. Participants received either 400 milligrams (mg) of chondroitin sulfate twice daily or a placebo. At the end of the trial, doctors rated the improvement as good or very good in 69 percent of those taking chondroitin sulfate but in only 32 percent of those taking the placebo.

Another way of comparing the results is to look at the maximum walking speed among participants. Individuals in the chondroitin group were able to improve their walking speed gradually during the trial, but walking speed did not improve in the placebo group. Additionally, there were improvements in other measures of osteoarthritis, such as pain levels, with benefits seen as early as one month. This suggests that chondroitin was able to stop the arthritis from gradually getting worse. Good results were seen in a twelve-month double-blind trial that compared chondroitin with the placebo in 104 people with arthritis of the knee and in a twelve-month trial of 42 participants.

Another study evaluated the intermittent or “on and off” use of chondroitin. In this study, 120 people received either a placebo or 800 mg of chondroitin sulfate daily for two separate, three-month periods in one year. The results showed that even when taken intermittently, chondroitin improved symptoms. Benefits were also seen in two short-term trials involving about 240 people.

Generally positive results were also seen in other studies, including one that found chondroitin about as effective as the topical anti-inflammatory drug diclofenac (Voltaren). However, a large, well-designed 1,583-participant study failed to find either chondroitin or glucosamine plus chondroitin more effective than a placebo. When this study is pooled with the two other best-designed trials, no overall benefit is seen. It has been suggested that chondroitin, like glucosamine, may show benefit primarily in studies funded by manufacturers of the product being tested.

Some evidence suggests that, like glucosamine, chondroitin might slow the progression of arthritis. An important feature of the foregoing study of forty-two people was that the people taking a placebo showed progressive joint damage over the year, but among those taking chondroitin sulfate, no worsening of the joints was seen. In other words, chondroitin sulfate seemed to protect to the joints of those with osteoarthritis from further damage.

A longer and larger double-blind, placebo-controlled trial also found evidence that chondroitin sulfate can slow the progression of osteoarthritis. The study enrolled 119 people and lasted three years. Thirty-four of the participants received 1,200 mg of chondroitin sulfate per day; the rest received a placebo. During the study, researchers took X-rays to determine how many joints had progressed to a severe stage.

During the three years of the study, only 8.8 percent of those who took chondroitin sulfate developed severely damaged joints, whereas almost 30 percent of those who took a placebo progressed to this extent. Similar long-term benefits were seen in two other studies, enrolling more than two hundred people.

Additional evidence comes from animal studies. Researchers measured the effects of chondroitin sulfateadministered both orally and via injection directly into the musclein rabbits in which cartilage damage had been induced in one knee by the injection of an enzyme. After eighty-four days of treatment, the damaged knees in the animals that had been given chondroitin sulfate had significantly more cartilage left than the knees of the untreated animals. Taking chondroitin sulfate by mouth was as effective as taking it through an injection.

Looking at the sum of the evidence, chondroitin sulfate may protect joints from damage in osteoarthritis. However, the scientific record suffers from a paucity of truly independent researchers.

S-adenosylmethionine. A substantial body of scientific evidence indicates that S-adenosylmethionine (SAMe) can relieve symptoms of arthritis. Numerous double-blind studies involving more than one thousand participants suggest that SAMe is approximately as effective for this purpose as standard anti-inflammatory drugs. However, there is no meaningful evidence that SAMe slows the progression of the disease.

One of the best double-blind studies enrolled 732 people and followed them for four weeks. Over this period, 235 of the participants received 1,200 mg of SAMe per day, while a similar number took either a placebo or 750 mg daily of the standard drug naproxen. Most participants had experienced moderate symptoms of osteoarthritis of either the knee or the hip for an average of six years.

The results indicate that SAMe provided as much pain-relieving effect as naproxen and that both treatments were significantly better than a placebo. However, differences did exist between the two treatments. Naproxen worked more quickly, producing readily apparent benefits at the two-week follow-up, whereas the full effect of SAMe was not apparent until four weeks. By the end of the study, both treatments were producing the same level of benefit.

In a double-blind study that compared SAMe with the newer anti-inflammatory drug Celebrex, the drug worked faster than the supplement, but, in time, both provided equal benefits. Evidence regarding slowing the progression of arthritis is limited to animal studies.

Avocado-soybean unsaponifiables. Special extracts of avocado and soybeans called avocado-soybean unsaponifiables (ASUs) have been investigated as a treatment for osteoarthritis, with promising results from studies that have been conducted with enrolling several hundred people.

For example, in a double-blind trial, 260 people with arthritis of the knee were given either a placebo or ASU at 300 or 600 mg daily. After three months, ASU significantly improved arthritis symptoms compared with a placebo. No significant difference was seen between the two doses tested. It does not appear that ASU can slow the progression of osteoarthritis.

Cetylated fatty acids. A type of naturally occurring fatty acid called cetylated fatty acids has shown growing promise for osteoarthritis. They are used both as topical creams and as oral supplements. Three double-blind placebo-controlled studies have found cetylated fatty acids helpful for osteoarthritis. Two involved a topical product, and one used an oral formulation.

In one of the studies using a cream, forty people with osteoarthritis of the knee applied either cetylated fatty acid or a placebo to the affected joint. The results over thirty days showed greater improvements in range of motion and functional ability among people using the real cream than among those using the placebo cream. Another thirty-day study also enrolled forty people with knee arthritis, and using cetylated fatty acid cream improved postural stability, presumably because of decreased pain levels. In addition, a sixty-eight-day, double-blind, placebo-controlled study of sixty-four people with knee arthritis tested an oral cetylated fatty acid supplement. The supplement also contained lesser amounts of lecithin and fish oil. Participants in the treatment group experienced improvements in swelling, mobility, and pain levels compared to those in the placebo group. Inexplicably, the study report does not discuss whether side effects occurred. While this is a promising body of research, it is far from definitive.

Advertising claims for cetylated fatty acids go far beyond the existing evidence. For example, many websites claim that cetylated fatty acids are more effective than glucosamine or chondroitin. However, this has not been proven.

Acupuncture.Acupuncture has shown inconsistent benefits as a treatment for osteoarthritis. A meta-analysis of studies on acupuncture for osteoarthritis found eight trials that were similar enough to be considered together. These studies enrolled 2,362 people. The authors of the meta-analysis concluded that acupuncture should be regarded as an effective treatment for osteoarthritis.

However, one study comprised almost one-half of all the people considered in this meta-analysis, and it failed to find real acupuncture more effective than sham acupuncture. In this study, 1,007 people with knee osteoarthritis were given either real acupuncture, fake acupuncture, or standard therapy over six weeks. Though both real acupuncture and fake acupuncture were more effective than no acupuncture, there was no significant difference in benefits between the groups. In general, larger studies are more reliable than small ones. For this reason, it is somewhat questionable when meta-analysis combines one large negative study and several smaller positive ones to come up with a positive outcome.

Another review concluded that real acupuncture produces distinct benefits in osteoarthritis compared to no treatment but that fake acupuncture is effective for osteoarthritis, too. When comparing real acupuncture to fake acupuncture, the difference in outcome, while possibly statistically significant, is so trivial as to make no difference in real life. In other words, virtually all the benefit of acupuncture for osteoarthritis is a placebo effect.

Other Proposed Natural Treatments

A six-week, double-blind, placebo-controlled study of 247 people with osteoarthritis of the knee evaluated a combination herbal product containing ginger and the Asian spice galanga (Alpinia galanga). The results showed that participants in the ginger and galanga group improved to a significantly greater extent than those receiving the placebo. However, despite news reports claiming that this study confirmed that ginger is effective for osteoarthritis, this study only provides information on the effectiveness of the herbal combination. The two double-blind studies performed on ginger alone were small and produced contradictory results. Furthermore, another study found that massage combined with the topical application of essential oils made from ginger and orange was no better than massage plus olive oil in people with osteoarthritis of the knee.

A three-week double-blind study of 220 people with osteoarthritis of the knee found that using a cream containing the herb comfrey reduced symptoms significantly more than a placebo cream.

White willow bark (Salix alba) contains salicin, an aspirin-like substance. A two-week, double-blind, placebo-controlled trial of seventy-eight people with arthritis found evidence that willow extracts can relieve osteoarthritis pain. However, another double-blind study enrolling 127 people with osteoarthritis found white willow less effective than a standard anti-inflammatory drug and no more effective than a placebo. The likely explanation for these contradictory results is that at usual doses, white willow provides relatively modest benefits.

The supplement MSM has shown promise for osteoarthritis when taken with glucosamine. Benefits were also seen in a twelve-week, double-blind, placebo-controlled trial of fifty people with osteoarthritis, utilizing MSM at a dose of three grams twice daily. However, in a comprehensive review of six studies involving 681 people with osteoarthritis of the knee, researchers concluded it is not possible to convincingly determine whether or not MSM is beneficial.

Other treatments with incomplete supporting evidence from double-blind trials include Ayurvedic herbal combination therapy, boswellia, cat’s claw, a proprietary complex of minerals with or without cat’s claw, devil’s claw, proteolytic enzymes, rose hips, soy protein, and vitamin B₃.

Traditional Chinese herbal medicine has also shown some promise for osteoarthritis. However, one study that compared a commonly used Chinese herbal product (Duhuo Jisheng Wan) to the drug diclofenac found that the herb worked more slowly than the drug but produced about an equal rate of side effects.

Strong evidence suggests that hyaluronic acid may help reduce osteoarthritis symptoms when it is injected into an affected joint. However, some studieshave failed to find any significant benefits.

Incomplete and inconsistent evidence from human and animal studies weakly suggests that green-lipped mussels might alleviate osteoarthritis symptoms. A poorly designed human study hints that krill oil might be helpful. One double-blind study involving dogs found some evidence of benefits with the use of elk velvet antlers. Numerous other herbs and supplements sometimes recommended for osteoarthritis include beta-carotene, boron, cartilage, chamomile, copper, dandelion, D-phenylalanine, feverfew, molybdenum, selenium, turmeric, and yucca. However, there is little evidence that these treatments are effective.

Other studies provide limited evidence that certain supplements proposed for osteoarthritis do not work. For example, a two-year double-blind study of 136 people with knee arthritis found vitamin E ineffective for either reducing symptoms or slowing the progression of the disease. In addition, a six-month, double-blind, placebo-controlled trial of seventy-seven people with osteoarthritis failed to find any symptomatic benefit with vitamin E. Similarly, in a large almost four-hundred-participant, five-year, double-blind, placebo-controlled study, using injected mesoglycan failed to slow the progression of osteoarthritis. A fairly small study failed to find the enzyme bromelain helpful for reducing symptoms.

Prolotherapy is a form of injection therapy popular among some alternative practitioners. A double-blind, placebo-controlled study evaluated the effects of three prolotherapy injections (using a 10 percent dextrose solution) at two-month intervals in sixty-eight people with osteoarthritis of the knee. At a six-month follow-up, participants who had received prolotherapy showed significant improvements in pain at rest and while walking, reduction in swelling, fewer episodes of “buckling,” and better range of flexion compared to those who had received a placebo treatment. The same research group performed a similar double-blind trial of twenty-seven people with osteoarthritis in the hands. The results at the six-month follow-up showed that range of motion and pain with movement improved significantly in the treated group compared with the placebo group.

Several double-blind, placebo-controlled studies suggest that pulsed electromagnetic field therapy, a form of magnet therapy, can improve symptoms of osteoarthritis. One small study provides extremely weak supporting evidence for the more ordinary form of magnet therapy: static magnets. A subsequent, much larger study of static magnets failed to find real magnets more effective than placebo magnets, but a manufacturing error may have obscured genuine benefitssome people in the placebo group were accidentally given active magnets. In another placebo-controlled trial, using a magnetic knee wrap for twelve weeks was associated with a significant increase in quadriceps muscle group strength in people with knee osteoarthritis.

Limited evidence supports using bee venom injections for osteoarthritis. Hot water therapy (balneotherapy), relaxation therapies, and various forms of exercise, including hatha yoga and Tai Chi, have also shown some promise, but further research is required to understand the benefits. The Arthritis Foundation supports the use of assistive devices in individuals with arthritis to reduce reliance on medication. These include braces, canes, knee tape, and shoe inserts. However, the American Academy of Orthopedic Surgeons recommends against the use of lateral wedge insoles for individuals with symptomatic osteoarthritis in the knee.

Herbs and Supplements to Use with Caution

Various herbs and supplements may interact adversely with drugs used to treat osteoarthritis, so one should be cautious when considering using herbs and supplements.

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