Erasmus MC Press Release Rotterdam, 16 September 2013
Losing some weight can reduce risk of osteoarthritis by a quarter
Family physicians and physiotherapists can use these results to encourage patients to change their lifestyle
If overweight women aged between 50 and 60 lose five kilos, they reduce the risk of knee osteoarthritis by 25 percent. This is one of the findings of human movement scientist Jos Runhaar, who will receive a PhD for his PROOF study on 17 September. The finding is part of the first prevention study in the world on osteoarthritis in which research was conducted to determine whether movement, a healthy diet and/or taking glucosamine sulphate contribute to preventing knee osteoarthritis. 
A total of 407 women aged between 50 and 60 participated in the study. They were all overweight (a BMI of >27), but had not or not yet developed osteoarthritis. The women were divided into two groups: one group was offered an individual intervention program including healthy eating and exercise. And the other group, a control group, received no intervention. Furthermore, both groups were divided into two smaller groups: half of each group was given glucosamine sulphate, a harmless dietary supplement thought to be attributed with properties that have a beneficial effect on knee osteoarthritis. The other half was given a placebo. The women were monitored for more than two years.

Data analysis did not definitely prove that a healthy diet and/or taking glucosamine sulphate had contributed to preventing knee osteoarthritis. Researcher Jos Runhaar: “The interventions, namely lifestyle change and taking glucosamine, appear to have influenced each other. The number of participants was not large enough to be able to properly evaluate the effects of the interventions independently of each other.”  

Runhaar is satisfied despite the fact that he was unable to demonstrate what he had expected beforehand. The finding that a relatively modest reduction in weight contributes to preventing osteoarthritis (a condition that costs society EUR 715 million per year) is encouraging. After all, 6.5 million people in the Netherlands are moderately to severely overweight. It was already known that overweight increases the risk of osteoarthritis.

“15 percent of the women in the group that lost five kilos or five percent of their total weight developed osteoarthritis, while this was 20 percent in the group that lost no weight. Family physicians and physiotherapists can use these results to encourage patients to change their lifestyle. In addition, the study gives useful starting points for further research. For example, we want to investigate whether bow legs correction contributes to the prevention of knee osteoarthritis. Knee osteoarthritis was significantly more common among participants with bow legs and a BMI greater than 30. We also want to study whether the participants managed to maintain their weight loss and whether weight loss also results in long-term knee osteoarthritis prevention.” 
Erasmus MC is the largest University Medical Center in the Netherlands. Our primary goal is a healthy population. Nearly 13,000 employees devote themselves every day to providing outstanding care, facilitating world-class education and conducting pioneering research. These professionals are instrumental in developing expertise on health and illness. They link the latest scientific insights to practical treatments and prevention measures to provide maximum benefit to patients and to enable healthy people to stay healthy longer. Being visibly better and leading the way in the areas of complex, innovative and acute care by collaborating with others: these are key ambitions at Erasmus MC.