It’s well known that dietary fiber helps lower cholesterol and prevent heart disease, aids in weight control, and keeps you "regular." Now a new study suggests it may also reduce the risk of developing painful knee osteoarthritis (OA).
Published in the Annals of Rheumatic Disease, the meta-analysis examined data from a total of 6,000 participants in two long-running observational studies: the NIH-sponsored Osteoarthritis Initiative and the Framingham Offspring Osteoarthritis study. Patients’ dietary habits were assessed at baseline. They were then assessed for OA symptoms every year for four years (Osteoarthritis Initiative) or after nine years (Framingham study).
The researchers found that fiber intake was inversely correlated with the risk of knee OA symptoms, such as joint stiffness, swelling, and pain. People who consumed the most fiber—21 grams a day on average in the Osteoarthritis Initiative, and 26 grams in the Framingham study— had a 30 and 61 percent lower riskof OA symptoms, respectively, compared with people who ate the least. Higher fiber intake also reduced the likelihood of knee pain worsening among participants who had that symptom at the start of the studies.
Osteoarthritis is the most common form of arthritis (joint disease), affecting more than 30 million people in the U.S. One in seven Americans will eventually develop knee OA, which becomes more common with age and with increasing body weight.
Bottom line: While these observational findings can only show an association between eating fiber and lower OA risk, not a causal relationship, they provide one more reason to make sure your diet contains plenty of this important nutrient. Aim for 14 grams of fiber for every 1,000 calories you consume each day—for example, 21 grams if you eat 1,500 calories a day and 35 grams if you eat 2,500 calories. Good sources include fruits, vegetables, whole grains, and legumes. For specific foods and amounts, see The Best Foods for Fiber.
Also see Best Pain Relief for Knee Arthritis.