What are natural treatments for osteoarthritis?

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 really knows
what causes the disease. Osteoarthritis is often described as wear-and-tear
arthritis, but evidence suggests that this simple explanation is not correct. 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 actually 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 appear to 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 actually speed the progression of
osteoarthritis by interfering with cartilage repair and by promoting cartilage
destruction. In contrast, two of the treatments described here might actually 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 the additional benefit of helping to prevent progressive joint damage.

Glucosamine. Inconsistent evidence hints that glucosamine
can reduce symptoms of mild to moderate arthritis; a small amount of evidence
indicates that regular use can slow down the gradual worsening of arthritis that
normally occurs with time.

Glucosamine appears to stimulate cartilage cells in the joints to make proteoglycans and collagen, two proteins essential for the proper function of joints. Glucosamine may also help prevent collagen from breaking down.

Glucosamine is widely accepted as a treatment for osteoarthritis. However, the supporting evidence that it works is somewhat inconsistent, with several of the most recent studies failing to find benefit. Two types of studies have been performed: those that compared glucosamine with 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 placebo. Benefits were also seen in other double-blind, placebo-controlled studies, enrolling more than eight hundred people and ranging in length 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.

Most recent studies, however, have not shown benefit. In four studies involving
almost five hundred people, the use of glucosamine failed to improve symptoms to
any greater extent than placebo. In a study involving 222 participants with hip
osteoarthritis, two years of treatment with glucosamine was no better than placebo
at improving pain or function. Another study involving 147 women with
osteoarthritis found glucosamine to be no more effective than home exercises over
an eighteen-month period. 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 placebo instead) did no worse than
people who stayed on glucosamine. In a fourth, large (1,583-participant) study,
neither glucosamine (as glucosamine hydrochloride) nor glucosamine plus
chondroitin was more effective than placebo. Another study also failed to find
benefit with glucosamine plus chondroitin. Finally, in a systematic review
including randomized trials involving 3,803 persons with osteoarthritis of the hip
or knee, researchers found that neither glucosamine alone, chondroitin alone, nor
the combination of glucosamine and chondroitin relieved pain. It appears that most
of the positive studies were funded by manufacturers of glucosamine products. Most
of the studies performed by neutral researchers failed to find benefit.

Many popular glucosamine products combine this supplement with methylsulfonylmethane (MSM). One study published in India reported that both MSM and glucosamine improved arthritis symptoms compared with placebo but that 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, as with the positive studies of glucosamine for reducing symptoms, both of these studies were funded by a major glucosamine manufacturer.

Osteoarthritis results when irregular bone growth occurs at the edge of a joint, causing impaired movement of the joint and pressure on nerves in the area.

A three-year, double-blind, placebo-controlled study of 212 persons found indications that glucosamine may protect joints from further damage. Over the course of the study, persons given glucosamine showed some actual improvement in pain and mobility, while those given placebo worsened steadily. Furthermore, X rays showed that glucosamine treatment prevented progressive damage to the knee joint. A separate three-year study enrolling 202 people found similar results.

A follow-up analysis five years after the conclusion of the foregoing two studies found suggestive evidence that the use of glucosamine reduced the need for knee replacement surgery. However, the aforementioned study involving 222 persons with osteoarthritis of the hip failed to show any significant change on X ray findings following two years of glucosamine treatment compared with 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 placebo.

Another way of comparing the results is to look at maximum walking speed among participants. Whereas persons in the chondroitin group were able to improve their walking speed gradually over the course of the trial, walking speed did not improve in the placebo group. Additionally, there were improvements in other measures of osteoarthritis, such as pain level, 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 placebo in 104 persons 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 placebo or 800 mg of chondroitin sulfate daily for two separate, three-month periods in one year. The results showed that even when it was taken intermittently, the use of chondroitin improved symptoms. Benefits were also seen in two short-term trials involving about 240 persons.

Generally positive results were also seen in other studies, including one that found chondroitin about as effective as the anti-inflammatory drug diclofenac. However, a large (1,583-participant) and well-designed study failed to find either chondroitin or glucosamine plus chondroitin more effective than placebo. When this study is pooled together 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 persons was that the persons 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 from further damage the joints of those with osteoarthritis.

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 placebo. Over the course of 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 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 sulfate (administered both orally and via injection directly into the muscle) in 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, it does appear that chondroitin sulfate may actually 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 persons 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 placebo or 750 mg daily of the standard drug naproxen. The majority of the 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 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 were providing equal benefits.

Evidence regarding slowing the progression of arthritis is limited to studies involving animals rather than people.

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 in studies enrolling several hundred people.

For example, in a double-blind trial, 260 persons with arthritis of the knee were given either placebo or ASU at 300 or 600 mg daily. The results over three months showed that the use of ASU significantly improved arthritis symptoms compared with placebo. There was no significant difference 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 have 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 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. In another thirty-day study, also enrolling forty people with knee arthritis, the use of 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 level compared to those in the placebo group. Inexplicably, the study report does not discuss whether or not 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, a number of Web sites claim that cetylated fatty acids are more effective than glucosamine or chondroitin. However, no comparison studies have been performed upon which such a claim could be rationally based.

Acupuncture. Acupuncture has shown inconsistent
benefit as a treatment for osteoarthritis. A 2006 meta-analysis (systematic
statistical review) 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, published in 2006, 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 two acupuncture groups. In general, larger studies are more reliable than small ones. For this reason, it is always somewhat questionable when meta-analysis combines one large negative study and a number of smaller positive ones to come up with a positive outcome.

Another review, published in 2007, 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 it might possibly be
statistically significant) is so trivial as to make no difference in real life. In
other words, virtually all of the benefit of acupuncture for osteoarthritis is a
placebo
effect.

Other Proposed Natural Treatments

A six-week, double-blind, placebo-controlled study of 247 persons 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 placebo. However, despite news reports claiming that this study proves ginger 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 persons with osteoarthritis of the knee.

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

The herb white
willow contains the aspirin-like substance salicin. A
two-week, double-blind, placebo-controlled trial of seventy-eight persons 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 placebo. The likely explanation for these contradictory results is
that white willow at usual doses provides relatively modest benefits.

The supplement MSM, as described in a foregoing study, 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 3 grams twice daily. However, in a comprehensive review of six studies involving 681 persons 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, yet produced about an equal rate of side effects.

Growing but definitive evidence suggests that the natural substance hyaluronic acid may help reduce osteoarthritis symptoms when it is injected into an affected joint. However, there is absolutely no reason to believe that oral hyaluronic acid should help, and one study failed to show any significant benefit.

Incomplete and inconsistent evidence from human and animal studies only weakly
suggests that green-lipped mussel might alleviate osteoarthritis symptoms.
A badly designed human study hints that krill oil might be helpful as well. One
double-blind study involving dogs found some evidence of benefit with elk velvet
antler.

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 to no 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, the use of 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 special form of injection therapy that is
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 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 placebo treatment. The same research group
performed a similar double-blind trial of twenty-seven persons with osteoarthritis
in the hands. The results at 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 special 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 benefits (some people in the placebo group were accidentally given active
magnets). In another placebo-controlled trial, the use of a magnetic knee wrap for
twelve weeks was associated with a significant increase in quadriceps (thigh
muscle) strength in persons with knee osteoarthritis.

Limited evidence supports the use of bee venom injections for osteoarthritis. Hot
water therapy (balneotherapy), relaxation therapies, and various forms
of exercise, including hatha yoga and Tai Chi, have
also all shown some promise. However, for none of these therapies is the
supporting evidence convincing.

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 the use of herbs and supplements.

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