A diet rich in fiber can reduce the risk of developing painful knee osteoarthritis . This is the main conclusion of the meta-analysis carried out by researchers from Tufts University in Boston (USA), and the University of Manchester (UK) and collected in the Annals of the Rheumatic Diseases journal.
Osteoarthritis is the most common form of arthritis and affects millions of adults around the world. In fact, it is estimated that nearly 10% of men and 18% of women age 60 and older live with symptomatic osteoarthritis.
Also known as wasting arthritis, this joint disorder affects the elderly in particular, with women over 50 being the most likely to develop the disease.
Therefore, the experts wanted to explore the link between a diet rich in fiber and the risk of developing knee osteoarthritis, because previous research had already extracted some health benefits from the inclusion of fiber in the diet, such as the decrease blood pressure and weight or improvement in blood sugar levels.
Thus, the meta-analysis examined two long-term studies on the benefits of a high-fiber diet: the Osteoarthritis Initiative (OAI) (which examined a total of 4,796 participants) and the Framingham Offspring Osteoarthritis Study (which included 1,268 participants) .
The researchers determined the fiber intake of the participants at the beginning of the study using a questionnaire. They also performed X-ray tests and recorded the most common symptoms of osteoarthritis, knee pain, stiffness and swelling.
The volunteers were followed up annually for 48 months as part of the OAI study, and were evaluated 9 years later as part of the Framingham study. They ate an average of 15 grams of fiber each day in the first study and 19 grams in the second study.
To avoid bias in the conclusions, they included factors that could have influenced the results, such as knee injuries, medications, lifestyle, alcohol consumption and physical exercise.
In general, statistical analysis revealed that a higher fiber intake was associated with a lower risk of osteoarthritis. Thus, those who consumed more fiber had a 30% lower risk of osteoarthritis in the first study and a 61% lower risk in the second study (those who took 19 grams of fiber per day).
Reference: Dietary intake of fiber and risk of knee osteoarthritis in two US prospective cohorts. Clinical and epidemiological research. Annals of the Rheumatic Diseases dx.doi.org/10.1136/annrheumdis-2016-210810
