Powder made from rosehip is more effective at reducing osteoarthritis pain than Tylenol, according to a study conducted by researchers from the University of California, and Fredericksburg Hospital, Copenhagen University Library and the University of Copenhagen in Denmark, and published in the journal Osteoarthritis and Cartilage.

Osteoarthritis is the most common form of arthritis - painful joint inflammation - and is believed to be triggered by injury to cartilage. Rheumatoid arthritis, a different condition, occurs when the body's immune system attacks its own joint tissue. An estimated 21 million people in the United States alone suffer from osteoarthritis, with studies suggesting that nearly 50 percent of the population will experience symptoms of the disease by age 65, while 80 percent will have asymptomatic arthritis.

Researchers reviewed the results of three prior studies on a total of 287 patients and found that after an average of three months, powdered rosehip was nearly three times more effective at reducing osteoarthritis pain than paracetamol, also known as acetaminophen and marketed as Tylenol, Panadol, Anacin-3, Tempra and Datril. Combinations of paracetamol with other drugs are also sold under a variety of brand names.

Rosehip was also 40 percent more effective than the common alternative osteoarthritis remedy glucosamine.

In contrast to pain medications, researchers did not observe constipation, diarrhea, drowsiness, gastrointestinal upset or any other side effects from the use of rosehip.

"This is very exciting news for arthritis sufferers," researcher Kaj Winther said. "Some of the main advantages of taking an alternative medication such as rosehip to reduce pain are that, firstly, it is readily available over-the-counter and, secondly, unlike traditional painkillers, it does not produce unpleasant side effects."

Rosehip is the fruit of the rose plant, and has a long history of use as an herbal remedy for conditions including rheumatoid arthritis, bladder infections, constipation, dizziness and headaches. It is known to contain vitamins A, C, D and E, as well as several flavonoids and essential fatty acids.