In early January this year, TIME magazine published an article (which you can read here) suggesting that maybe turmeric wasn’t all it was cracked to be, that it wasn’t a miracle superfood, and that research findings weren’t communicated well by the media. As always, there’s a small amount of truth in this, as the alternative health media can often overstate the benefits of turmeric without taking the time to understand the evidence base (traditional and scientific). Does this mean that TIME was right, though? Have the benefits of turmeric been blown out of proportion?
Most of TIME’s article about turmeric was derived from one study, a review published by the Journal of Medicinal Chemistry, titled ‘The Essential Medicinal Chemistry of Curcumin’. Check out the full-text article here. This review was riddled with scientific errors of the worst kind, and is a wonderful example of bad research.
Firstly, I would like to say that the authors of this review have excellent credentials, and in their fields of chemistry, chemical analysis and pharmacology there is no doubt that they have the qualifications needed to assess phytotherapeutics in those fields.
The difficulty is, that when you start analyzing curcumin, there is a necessity to understand how to perform analyses on the clinical data (data gathered from research involving humans) not the pharmacological data, something which I do not think was done adequately. The authors state that there have been more than 120 clinical trials involving curcumin, and yet in order to review it’s efficacy, they selected four trials, claiming they were archetypal. There is such a strong potential for bias here as to throw the internal validity of this study completely in shadow. The clinical evidence for their major claim that curcumin and turmeric are ineffective treatments has not been proven, and the selection of studies is such that there was almost certainly some kind of bias, even if unconscious.
Mainly, the review focuses on the activity of curcumin itself, individually, despite the fact that it has been well known for the better part of a decade that curcumin is one of three major curcuminoid substances (curcumin, demethoxycurcumin and bisdemthoxycurcumin) that make up the therapeutic activity of turmeric extracts often sold as curcumin. Much of the very good information that they have presented regarding the pharmacology and reactivity of curcumin under pharmacological and chemical test conditions is therefore questionable. There are so many Type 1 errors here, and for those unfamiliar with the term, it means that it’s the authors job to disprove the fact that turmeric works and they have failed to do this repeatedly as their selection and presentation of research is biased.
In their area of specialty, chemistry, the authors make some very good points about how it is difficult to analyze the curcumin content of turmeric and its activity in chemical analysis due to its PAINS status (interferes with pan-assays of substances), however, their conclusion that it is an invalid lead compound would have better been the subject of a chemistry specific journal article or research project. It is inappropriate to make that claim without their own research when there is a wealth of contradictory pharmacological evidence and more importantly, a wealth of successful clinical evidence suggesting that curcumin is an active therapeutic substance.
Finally, curcumin is one of many hundreds of phytotherapeutic compounds in turmeric, and to make a claim that there is no scientific basis for the benefits of turmeric is to disregard the research into all of those other compounds. Turmeric does not = curcumin, and this is the main mistake made by TIME and so much of the media. It’s so important to be clear about what you’re using, and why. Turmeric has a rich history of traditional use as a whole food spice, and although there isn’t any clinical evidence for turmeric, there is a wealth of good, unbiased research that confirms the benefits of curcumin. Make of it what you will, all we can do is give you the facts.
Yours in good health,