Osteoarthritis is a common chronic condition. Ten per cent of Canadians age 15 and over have osteoarthritis. The average age of diagnosis is 50. https://tinyurl.com/y74lqhsg Osteoarthritis is more common in women than men.
Osteoarthritis “is caused by a breakdown of cartilage in joints causing bones to rub together resulting in pain, stiffness and eventual loss of use. There are some forms of osteoarthritis that appear to be genetically driven and others that are a result of injury, overuse or advanced age” (Joint Health, February 2008, https://tinyurl.com/y9ec9p6c).
Osteoarthritis (OA) is often viewed as a normal part of ageing. OA is also linked to obesity because excess weight puts a heavier load on weight-bearing joints. Surgery to replace hips and knees has become increasingly common. According to the Canadian Institute for Health Information, approximately 50,000 hip replacements and 60,000 knee replacements were performed in Canada in 2013-2014. These figures are on the rise even when population growth and ageing are accounted for. https://tinyurl.com/ycqsro2w
A Harvard study on osteoarthritis examined 2,000 skeletons including medical school cadavers and ancient remains found by archeologists. After controlling for age and weight, the study found that knee osteoarthritis has doubled in prevalence since the Second World War; while 16 per cent of the more recent skeletons had knee OA, only eight per cent of the earlier skeletons did. What are we doing or not doing differently that is resulting in more OA than our ancestors?
The researchers agree that age and obesity are two major risk factors for OA. They also hypothesize that the absence of physical activity may be what is causing more OA in modern times. Thinking of OA as a wear-and-tear disease may be inaccurate; it may be due to more sitting and less moving. Perhaps our overweight ancestors had less OA than overweight people after the mid-20th century because they were more active. One of the study’s authors, David Felson of Boston University Medical School, says that “exercise makes the joints more strain-resistant and that the cartilage gets thicker and the muscles that support and protect the joints get stronger.” The paper’s senior author Daniel Lieberman of Harvard University states that “knee osteoarthritis is not a necessary consequence of old age. We should think of this as a partly preventable disease.” https://tinyurl.com/y8jesf5u
What if you already have OA? Another study examined the effects of weight loss via different strategies on participants’ knee osteoarthritis. Overweight and obese adults age 55-plus with knee osteoarthritis were randomly assigned to either a diet group, an exercise group, or a group that combined diet and exercise – 399 participants completed the study. The participants in the diet-and-exercise group and those in the diet-only group lost more weight (a mean of roughly 10 per cent of body weight) than those in the exercise-only group (roughly two per cent) and had greater measurable reductions in inflammation than those in the exercise-only group. Participants in the diet-and-exercise group also had less pain, better function, faster walking speed and better self-reported physical quality of life than those in the exercise-only group. Independent of group assignment, participants who lost 10 or more per cent of body weight had bigger improvements in function, in inflammation and in pain, and bigger reductions in knee compressive force.
The findings suggest that intensive weight loss may have both anti-inflammatory and biomechanical benefits. Combining an appropriate diet and exercise program enables overweight and obese people to achieve improvements in symptoms greater than with just diet or just exercise. https://tinyurl.com/ya743kvc
What are the practical applications of these studies’ findings to your day-to-day life? With the ageing population and the prevalence of OA on the rise, a healthy lifestyle that includes staying physically active and eating well seems like a good preventative strategy.
If you already have OA, exercise avoidance is the wrong approach; it’s a matter of finding the right exercise. According to the Arthritis Foundation, “exercise is considered the most effective non-drug treatment for reducing pain and improving movement in osteoarthritis.” https://tinyurl.com/yanmwbyk
Exercise maintains and improves your ability to move and function and improves blood flow to the joints. Losing excess weight takes additional stress off the joints and that, in turn, can salvage cartilage and reduce pain. Osteoarthritis-appropriate cardiorespiratory exercises include swimming and using joint-friendly exercise machines such as a stationary bicycle and an elliptical. Strength training, if done properly, builds strong muscles which support and protect affected joints. Exercise can also reduce the psychological stress of living with a painful condition.