This summary of a Cochrane review presents what we know from research about the effect of S-Adenosylmethionine on osteoarthritis.
The review shows that in people with osteoarthritis:
- We are uncertain whether S-Adenosylmethionine affects pain or your ability to use your knee because of the low to moderate quality of the evidence.
- S-Adenosylmethionine may not have any side effects. We often do not have precise information about side effects and complications. This is particularly true for rare but serious side effects.
What is osteoarthritis and what is S-Adenosylmethionine (SAMe)?
Osteoarthritis (OA) is a disease of the joints, such as your knee or hip. When the joint loses cartilage, the bone grows to try to repair the damage. Instead of making things better, however, the bone grows abnormally and makes things worse. For example, the bone can become misshapen and make the joint painful and unstable. This can affect your physical function or ability to use your knee.
S-Adenosylmethionine is popular dietary supplement available over the counter in drug stores or health food stores. It is also a naturally occurring chemical that is produced in the body. SAMe is not found in foods, so it must be taken as a supplement.
Best estimate of what happens to people with osteoarthritis who take S-Adenosylmethionine (SAMe)
Pain
- People with S-Adenosylmethionine and people with placebo are equally likely to respond to treatment (difference of 0%). This could be the result of chance.
- People who took S-Adenosylmethionine had an improvement in their pain of about 2 on a scale from 0 (no pain) to 10 (extreme pain) after using it up to 3 months.
- People who took a placebo had an improvement in their pain of also about 2 on a scale from 0 (no pain) to 10 (extreme pain) after using it up to 3 months.
Physical Function
- People with S-Adenosylmethionine and people with placebo are equally likely to respond to treatment (difference of 0%). This could be the result of chance.
- People who took S-Adenosylmethionine had an improvement in their physical function of about 1 on a scale of 0 (no disability) to 10 (extreme disability) after using it up to 3 months.
- People who took a placebo had an improvement in their physical function of also about 1 on a scale of 0 (no disability) to 10 (extreme disability) after using it up to 3 months.
Side effects
- 4 more people experienced side effects with S-Adenosylmethionine than with placebo (difference of 4%). This could be the result of chance.
- 19 people out of 100 who used S-Adenosylmethionine experienced side effects (19%).
- 15 people out of 100 who used a placebo experienced side effects (15%).
The current systematic review is inconclusive, hampered by the inclusion of mainly small trials of questionable quality. The effects of SAMe on both pain and function may be potentially clinically relevant and, although effects are expected to be small, deserve further clinical evaluation in adequately sized randomised, parallel-group trials in patients with knee or hip osteoarthritis. Meanwhile, routine use of SAMe should not be advised.
Osteoarthritis is the most common form of joint disease and the leading cause of pain and disability in the elderly. S-Adenosylmethionine may be a viable treatment option but the evidence about its effectiveness and safety is equivocal.
We set out to compare S-Adenosylmethionine (SAMe) with placebo or no specific intervention in terms of effects on pain and function and safety outcomes in patients with knee or hip osteoarthritis.
We searched CENTRAL, MEDLINE, EMBASE, CINAHL and PEDro up to 5 August 2008, checked conference proceedings and reference lists, and contacted authors.
Randomised or quasi-randomised controlled trials that compared SAMe at any dosage and in any formulation with placebo or no intervention in patients with osteoarthritis of the knee or hip.
Two independent authors extracted data using standardised forms. We contacted investigators to obtain missing outcome information. We calculated standardised mean differences (SMDs) for pain and function, and relative risks for safety outcomes. We combined trials using inverse-variance random-effects meta-analysis.
Four trials including 656 patients were included in the systematic review, all compared SAMe with placebo. The methodological quality and the quality of reporting were poor. For pain, the analysis indicated a small SMD of -0.17 (95% CI -0.34 to 0.01), corresponding to a difference in pain scores between SAMe and placebo of 0.4 cm on a 10 cm VAS, with no between trial heterogeneity (I2 = 0). For function, the analysis suggested a SMD of 0.02 (95% CI -0.68 to 0.71) with a moderate degree of between-trial heterogeneity (I2 = 54%). The meta-analyses of the number of patients experiencing any adverse event, and withdrawals or drop-outs due to adverse events, resulted in relative risks of 1.27 (95% CI 0.94 to 1.71) and 0.94 (95% CI 0.48 to 1.86), respectively, but confidence intervals were wide and tests for overall effect were not significant. No trial provided information concerning the occurrence of serious adverse events.