Turmeric and curcumin have been used in traditional Chinese medicine as well as Ayurvedic medicine for hundreds of years. And only recently has Western medicine and the scientific community discovered that curcumin has a surprisingly wide range of beneficial properties including reducing pain and inflammation. But does it actually work and what does the evidence say? Let’s review the results of some recent clinical trials.
Curcumin is a natural polyphenol and is the active ingredient in turmeric which is a spice heavily used in Asian cuisine. Specifically when looking at pain and inflammation, in vivo and in vitro studies have shown that curcumin has both anti-inflammatory as well as antioxidant effects. It works by down regulating chemical mediators such as NF kappa beta and inhibiting the production of proinflammatory cytokines such as interleukin 1 beta, interleukin 8, and tumor necrosis factor alpha. Curcumin can also lead to decreased oxidative stress by decreasing the production of free radicals.
Now in addition to these anti-inflammatory effects, curcumin may also have disease modifying and chondroprotective effects. Laboratory studies have shown that curcumin can stimulate extracellular matrix synthesis which is important for the structure and strength of cartilage. Other studies have shown that curcumin can down regulate matrix metalloproteinases which is an enzyme that breaks down cartilage. All of this in theory would lead to a healthier and happier joint.
So that’s the simplified version behind the science of turmeric and curcumin. Now the question becomes, does it actually work in practice and what do the clinical trials show? I’m going to focus the discussion around osteoarthritis mainly because there have been multiple randomized controlled trials looking at the use of curcumin for the treatment of symptomatic knee osteoarthritis.
First and foremost, I think it’s important to point out that some of these studies were funded by industry and pharmaceutical companies. So to try to minimize the effect of bias, we want to look at systematic reviews and meta-analyses which aggregate data from multiple studies including ones that were not funded by industry.
This recent study is a great example. This was a systematic review and meta-analysis that included 15 studies for a total of 1670 patients. They found that curcumin was significantly more effective than placebo in the improvements for VAS pain scores, total WOMAC osteoarthritis index score, WOMAC pain score, WOMAC functional score, and WOMAC stiffness scores. In addition, they found that the effects of curcumin were just as strong as taking NSAIDs such as ibuprofen or naproxen in the improvements of pain and function.
The authors go on to conclude that curcumin “can be expected to achieve considerable analgesic and functional promotion effects for patients with symptomatic knee osteoarthritis in the short term, without inducing an increase of adverse events.” The authors do point out that the included studies are highly heterogeneous and may be low quality and that further studies are necessary to investigate both long term safety and efficacy of curcumin.
I think the important thing to highlight here is that not only does curcumin seem to help treat symptoms related to arthritis, but that the effect size is on par with NSAID medications such as ibuprofen and naproxen. These medications have strong anti-inflammatory effects and are often recommended for painful orthopedic conditions. However, NSAIDs come with serious side effects especially when taken long term. Complications include gastrointestinal bleeding, renal failure, worsening hypertension, and cardiovascular complications such as heart attacks and strokes.
This other study wanted to assess the efficacy as well as safety of turmeric and curcumin for the treatment of symptomatic knee osteoarthritis. They too found that turmeric extracts significantly reduced knee pain and improved physical function and that the effects were greater than placebo and on par with NSAIDs. In addition, this study found that turmeric extracts led to fewer side effects when compared to NSAIDs and had the same safety profile as placebo.
The authors go on to conclude that “Turmeric extract is a safe and effective option for the symptomatic management of knee osteoarthritis, compared to placebo or NSAIDs.” They too go on to write that current evidence is heterogenous and have moderate risk for bias and that more clinical studies are needed to assess outcomes.
Ok so there does seem to be a growing body of evidence that turmeric and curcumin can work to treat symptoms related to knee osteoarthritis. But does it have any disease modifying effects? Laboratory studies have shown that curcumin can improve the structure and strength of cartilage and potentially slow the progression of arthritis. What we want to know is if there is any evidence that this is true in clinical trials.
That’s what this study tried to answer. This was a randomized controlled trial to determine if curcumin can reduce knee symptoms as well as effusion and synovitis in patients with symptomatic knee osteoarthritis. They enrolled 70 participants all with knee osteoarthritis as well as signs of effusion and synovitis. This means they all had significant swelling and inflammation in the knee related to the arthritis. The participants were randomized to either take curcumin or placebo. The authors took MRI scans at baseline as well as at the 3 month follow up.
The study found that the group taking curcumin had significant improvements to visual analog pain scores when compared to placebo. There were also improvements when assessing WOMAC pain and function scores as well as weight bearing pain and non weight bearing pain. However MRI scans did not show any differences between effusion synovitis volume between the two groups. MRI scans also did not show any differences in the T2 relaxation time between the two groups. This means that the curcumin group did not have additional benefits to their articular cartilage when compared to the placebo group. Now it’s important to point out that the study only lasted 3 months and in general, disease modifying effects are typically seen over many months if not years. Nevertheless, no differences between the two groups were seen.
The authors go on to conclude that “ Multicenter trials with larger sample sizes are needed to assess the clinical significance of these findings.”
Ok so what are my thoughts on these studies and what do I recommend to my patients? Let’s first talk about safety because this is where curcumin really shines. Turmeric and curcumin have been used in Eastern medicine for thousands of years and have a long established safety record. This of course cannot be said of other common over the counter pain medications we typically recommend for the treatment of musculoskeletal pain. As we discussed earlier NSAIDs such as ibuprofen and naproxen can have rather serious side effects and really do need to be used with caution. In the clinical trials, curcumin was found to have the same safety profile as taking placebo.
Now the question becomes, does taking turmeric and curcumin actually work? I think the data we have so far seems to suggest that curcumin does work and that the effect size may be as large as taking NSAIDs. Critics will continue to argue that some of the studies included in the systematic reviews are funded by industry and should be taken with caution. And this is why every paper so far has written that more clinical trials need to be done.
So what do I currently recommend to my patients? I do think taking turmeric and curcumin supplements can help with symptomatic knee osteoarthritis. It really seems like a great alternative to NSAIDs and has an excellent safety profile. We still need to flush out the ideal dosing but the typical recommended dose is to take between 1000 mg to 2000 mg daily.
Lastly, I want to say that supplements should not be relied upon as monotherapy. It is very important to take a multi modal approach to treat osteoarthritis to not only reduce pain and symptoms, but also to slow the progression of arthritis. I recommend all patients perform exercise therapy which includes both aerobic exercises as well as strength training exercises. I also highly recommend injection therapy with either platelet rich plasma injections or hyaluronic acid injections to treat the biochemical environment of the joint.