For people with knee osteoarthritis (OA) who also happen to love grapes, the Texas Woman´s University has some good news. According to a study conducted by its researchers, a diet rich in grapes may have a beneficial effect on pain levels and joint flexibility. These benefits are ascribed to the polyphenols found in the fruit.
The research team was led by Dr Shanil Juma, who presented the findings at the Experimental Biology conference held early this month in San Diego, California. The study involved 72 male and female knee OA patients, the aim being to explore the impact of grape consumption on disease symptoms. One group was given whole grape freeze-dried powder and the control group received a placebo powder.
The results showed that all subjects on the grape-enriched diet experienced a significant reduction in the level of self-reported pain during activity and an overall improvement in symptoms. The analysis by gender revealed that the effect was stronger in women. The researchers also established age-related differences: for grape-consuming subjects aged under 64, very hard activity increased by 70%. In the case of placebo consumers in that age range, there was a substantial decline in such activity. However, subjects older than 65 reported a drop in moderate to hard activities regardless of the group they were assigned to.
Additionally, men on the grape-enriched diet were found to have accelerated cartilage metabolism compared to their placebo-consuming counterparts. But such increased levels of IGF-1 (an important cartilage growth factor) were not observed in the case of women consuming the grape powder.
Juma said the findings were very encouraging for knee OA patients but the link between grape consumption and symptom relief needs to be investigated further. Specific effort must be made to understand the differences in the age- and gender-based results, he added.