The study is said to be the first clinical trial to investigate the potential benefits of pomegranate juice in people with osteoarthritis.
Writing in the peer-reviewed and PubMed listed Journal of the Science of Food and Agriculture, Iranian scientists report that pomegranate juice consumption was associated with significant decreases in scores on the Western Ontario and McMaster Universities Osteoarthritis index (WOMAC) for physical function and stiffness.
The potential benefits were proposed to be linked to inhibition of matrix metalloproteinases (MMPs), which are known to play a role in the irreversible breakdown of cartilage. The researchers found that participants consuming the pomegranate juice had significantly lower levels of MMP-13, compared to the control group.
In addition, pomegranate juice was also found to increase glutathione peroxidase, an antioxidant enzyme.
The study adds to a long list of potential health benefits for the fruit. Pomegranate, a rich source of antioxidants, has been linked to improved heart health, prostate health, and joint health. It is these antioxidants, and particularly ellagitannin compounds like punicalagins and punicalins, which accounts for about half of the fruit's antioxidant ability, that are reportedly behind the proposed health benefits.
The researchers recruited 38 people with knee osteoarthritis and randomly divided them into two groups: One group received 200 mL per day of pomegranate juice; while the other group received no intervention.
Results showed that, after six weeks of intervention, the WOMAC total score decreased in participants in the pomegranate juice from 39.6 to 32.4, while WOMAC scores in the control group increased slightly from 39.0 to 40.6.
In addition, scores of stiffness and physical function also improved significantly in the pomegranate juice group.
However, no effects for pain were observed, said the researchers.
“Further studies with longer intervention periods and a double-blind placebo controlled design are suggested to be done. Moreover, it is recommended to evaluate polyphenolic components in future surveys,” they concluded.
Source: Journal of the Science of Food and Agriculture
Published online ahead of print, doi: 10.1002/jsfa.7647
“The effect of pomegranate juice on clinical signs, matrix metalloproteinases and antioxidant status in patients with knee osteoarthritis”
Authors: N. Ghoochani et al.