Regular grape consumption may offer benefits for symptomatic knee osteoarthritis, according to a recent study.

Researchers from Texas Woman's University found that grape consumption may help alleviate pain associated with symptomatic osteoarthritis of the knee, and improve joint flexibility and overall mobility. They attribute these potential benefits to the polyphenols found in grapes.

Osteoarthritis is a condition where the natural cushioning between joints - the cartilage - wears away. It affects millions, and more than 27 million people have osteoarthritis and knees are an area most commonly affected. Osteoarthritis is more likely to occur in people over 45 years of age, and women are more likely to have osteoarthritis than men.

"These findings provide promising data that links grape consumption to two very important outcomes for those living with knee osteoarthritis: reduced pain and improvements in joint flexibility,"Shanil Juma, lead investigator, said in a statement.

For the study, researchers conducted sixteen week clinical study designed to investigate the benefits of grape consumption on inflammation and osteoarthritis outcomes. Seventy-two men and women with knee osteoarthritis (OA) were assigned to either consume grapes in the form of a whole grape freeze-dried powder, or a placebo powder.

Researchers found that both men and women consuming a grape-enriched diet had a significant decrease in self-reported pain related to activity and an overall decrease in total knee symptoms. This beneficial effect was more pronounced in females.

Additionally, age-related differences were observed: there was a 70 percent increase in very hard activity for those under 64 years of age consuming the grape powder, while those receiving the placebo reported a significant decrease in very hard activity. Participants over 65 years, whether consuming grapes or the placebo, reported a decline in moderate to hard activities.

Researchers said evidence of increased cartilage metabolism was observed in men consuming the grape-enriched diet; they had higher levels of an important cartilage growth factor than those on placebo. This protective effect was not observed in the females.

The findings were presented last week at the Experimental Biology conference in San Diego, Calif.