A study conducted at UAB, published in Pain Medicine, shows a low-carbohydrate diet was more effective in reducing pain intensity than a low-fat diet in adults ages 65-75 suffering from osteoarthritis. Researchers also found the low-carb diet decreased serum levels of the adipokine leptin and a marker of oxidative stress.

The randomized controlled pilot study of 21 adults (nine males, 12 females) tested the efficacy of low-carb and low-fat dietary intervention. Study particpants were asked to follow one of the two dietary interventions or continue to eat as normal for a period of 12 weeks. Functional pain, self-reported pain, quality of life and depression were assessed every three weeks. Serum from before and after the diet intervention was analyzed for oxidative stress.

To test functional pain, researchers asked participants with knee pain to stand from a sitting position a number of times, walk a set distance, and then tested their knees for pain response by repeated stimulation

"Our work shows people can reduce their pain with a change in diet," said Robert Sorge, PhD, lead author of the study. "Many pain medications for pain cause a host of side effects, whereas this diet may provide additional benefits such as reduced risk for heart disease, diabetes and weight loss."

"Opioids may work well for short-term severe pain. But they have limited usefulness over the long term and, in some cases, perform no better than over-the-counter drugs," Sorge said.

The advantage of a change in diet is that it can be done without long-term anti-inflammatory use or prescription medications, and it can be tailored to taste and preferences.

"Diet will never cure pain, but our work suggests it can reduce it to the point where it does not interfere with daily activities to a high degree," Sorge said.

Diets such as the Mediterranean diet (a partial low-carbohydrate diet) have been shown to reduce inflammation in arthritis patients and self-reported pain in osteoarthritis and rheumatoid arthritis. This previous work supported Sorge's hypothesis that, by lowering the intake of refined carbohydrates, oxidative stress would decrease and functional pain would be improved.

However, diet intervention studies to date have focused exclusively on self-reported pain, and not assessment of functional pain, which Sorge believes may be a better indicator of efficacy.