Low Carb Diet Provides Relief From Knee Osteoarthritis

A change in diet can reduce the intense pain caused by knee osteoarthritis, the most prominent form of arthritis, according to research findings published this week in the journal Pain Medicine. 

The study conducted at the University of Alabama at Birmingham 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 found the low-carb diet specifically increased the quality of life and decreased serum levels of the adipokine leptin, a marker of oxidative stress.

The study included 21 adults (nine males, 12 females) who were tested for the efficacy of low-carb and low-fat dietary interventions in pain management in adults ages 65-75 with knee osteoarthritis, the most prominent form of arthritis. This osteoarthritis affects approximately 15 percent of the United States population and, because of its affinity for the lower, weight-bearing joints, has become one of the leading causes of disability in the lower extremities in an ever-aging population.

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.

Study participants 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.

The results showed that the low-carb diet reduced pain intensity and unpleasantness in some functional pain tasks, as well as self-reported pain, especially when compared to the low-fat diet and usual diet participants.  In addition, the low-carb diet also significantly reduced oxidative stress and the adipokine leptin compared with the other diets. That finding was particularly interesting since reduction in oxidative stress was related to reduced functional pain, or pain associated with engaging in normal, everyday things.  

Many medications for pain cause a host of side effects that may require other drugs to reduce.  Because there is no curative treatment for knee osteoarthritis outside of a knee replacement, persistent pain is commonly treated with opioids, acetaminophen and nonsteroidal anti-inflammatory drugs — all of which have unpleasant side effects if used for an extensive period.  Over-the-counter anti-inflammatory medication side effects can include high blood pressure, liver or kidney problems, stomach ulcers and pain, heartburn, allergic reactions such as rashes, wheezing and throat swelling, and a tendency to bleed more, especially when taking aspirin.

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.

Interestingly, the researcher noted that weight loss alone did not reduce pain in study participants.  In fact, the quality of the diet and types of foods consumed have more to do with pain reduction than weight loss, according to our findings. 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 work supported the hypothesis that, by lowering the intake of refined carbohydrates, oxidative stress would decrease and functional pain would be improved.

Thanks for reading.

Journal Reference:

Strath, L.J. et. al, The Effect of Low-Carbohydrate and Low-Fat Diets on Pain in Individuals with Knee Osteoarthritis, Pain Medicine, pnz022, https://doi.org/10.1093/pm/pnz022(March 13, 2019)