quote:
Osteoarthritis Patients May Benefit From Drinking Tart Cherry Juice
Just a moment...
I prefer to get my science from the horse's mouth, not a science journalist's. First, let me point out that the "Journal of Food Studies" is not on the Master Journal List. Second, Macrothink - the publisher - appears to be operating a 'pay to publish' model, which routinely have poor to non-existent peer review.
Moving on:
quote:
The study, conducted by researchers from Oregon Health and Science University, involved 20 women aged 40-70 with inflammatory osteoarthritis.
It was actually 21 women, though one dropped out partway due to adverse reaction to the placebo. Their headline results actually dropped one participant so it was actually 19 to get their conclusion. This is a small study then. The kind of study that might be performed as a pilot, or by a university student. Strong conclusions cannot be drawn.
The researchers found that drinking tart cherry juice two times per day for three weeks resulted in considerable reductions in vital inflammation markers
Of the four markers they measured, only one of them had a statistically significant reduction. And only if they excluded one of the participants from the analysis (ie., by throwing out 5% of their data, whether for good reason or not). If they included the one person who had the same very high values before and after cherries - the significance vanished.
Here it is from their study:
quote:
There were no statistically significant differences between the Tart Cherry and Placebo
groups at baseline for all biomarkers.
One subject had an extremely high CRP post test (41 mg/L) and this sample assay was
repeated and found to be the same value. The analysis was performed again without this
outlier value, see Table 2. Results show a statistically significant reduction in CRP in the tart
cherry group when this outlier is removed.
.
Still no statistically significant impact on the other markers. And by statistically significant, we really are talking on the edge of significance p=0.016
The reduction still put the participants in the 'high' category of CRP (over 3).
The question one wants to ask is - does the drop in CRP correlate to an actual reduction in inflammation or is it just a drop in CRP - which is just a marker?
It cites
Neutrophils injure cultured skeletal myotubes to support the cherry - CRP link but that paper doesn't seem to mention either cherries or CRP so I'm at a loss there.
They also cite
Efficacy of a tart cherry juice blend in preventing the symptoms of muscle damage. but that's the wrong cite, as that study cites
Consumption of Bing Sweet Cherries Lowers Circulating Concentrations of Inflammation Markers in Healthy Men and Women. This study had 18 participants (so also small) and contained no placebo group. The change in CRP was 25% at peak. Again, other inflammation markers did not change. Their conclusion is essentially that it's interesting but requires a larger study.
So that's a bit of a wash. Has anyone done a decent sized study? Do we know if the reduction in CRP is related to actual drops in inflammation or pain?
The largest study I could find had 58 participants
Randomized double-blind crossover study of the efficacy of a tart cherry juice blend in treatment of osteoarthritis (OA) of the knee.
quote:
In conclusion, WOMAC scores improved significantly when patients were taking tart cherry juice but this effect was not significantly better than placebo. Additionally, patients had significantly decreased hsCRP when taking cherry juice compared to placebo. The decline in hsCRP when taking cherry juice was associated with improved WOMAC scores.
The scores improved slightly, but not by much. Nothing to sniff at, but hardly 'considerable reductions' in pain. The pain score on cherries went from 42 to 36 with huge error margins (in the region of plus or minus 25).
Certainly interesting, but as far as I can see, nothing particularly spectacular at this time.
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