Pain, stiffness and swelling inducing osteoarthritis (OA) is the most common form of arthritis, affecting millions of people worldwide. With those odds, it may seem nearly impossible to outrun the inevitable, but it is worth understanding the root causes and symptoms of the debilitating condition.
OA occurs when the protective cartilage on the ends of your bones wears over time, primarily effecting large joints, such as the knee, hip, neck and lower back. Pain levels vary, becoming excruciating and incapacitating to many.
It was assumed for years that regular activities like jogging could speed up joint degeneration, giving OA the nickname “wear and tear” arthritis. This misconception was supported by a study published in Arthritis & Rheumatism, in 1993. In the year-long study using dogs, 10 beagles were put on treadmills to run. By the end of the study, the dogs were running 25 miles a day. Tissue samples from the dogs’ knees showed as much as 35% loss of glycosaminoglycan, an essential carbohydrate that strengthens cartilage. The results of the study seemed to indicate that long-distance running had detrimental effects on cartilage, eventually leading to OA, casting a shadow on the once presumed healthy habit of jogging.
Luckily, scientific study, being a self-correcting process, didn’t stop there. Researches began to question the prior studies that were giving running such a poor reputation – suggesting that the earlier animal tests imposed far more stress on joints than average human activity. New studies are finding that a lifetime of running doesn’t actually increase an individual’s risk for OA. In a study published in 2008, researches tracked the health of 45 long-distance runners over a span of 20 years. X-rays showed no effect on their joints, even after running thousands of miles over time. A Stanford University study looked at how humans walked and found that the stress of exercise actually made cartilage thicker and healthier. Although there are varying results from different reports, several more studies examining the effects of running on joints proved to support the conclusion that running isn’t the bad guy.
Based on the existing evidence, moderate running may not be associated with higher incidence of OA in healthy people and it may even work to facilitate healthier joints. If running doesn’t trigger OA, then what does?
Here are four factors that will accelerate osteoarthritis:
1. Lack of Exercise
Getting too little exercise can shrink cartilage, which lacks a blood supply and must absorb nutrients and expel wastes through passive diffusion. Stress on the joint enhances that process.
Trauma to ligaments, even if repaired, can change the mechanics of walking and shift weight distribution on knee cartilage. Weakened muscles also can pose a threat to cartilage.
3. Obesity and Overweight
Weight has by far the greatest impact – so much so that if we were able to deal with obesity effectively, about 50% of osteoarthritis would just go away. Obese people with OA who lose just 5% of body weight experience at least a 25% reduction in symptoms. That’s equal to the best anti-inflammatories.
4. Age Factor
Eventually, though, for reasons not yet known, cartilage loses the ability to repair itself. For most people, the tipping point occurs around age 50. After that, changes to the load on a joint may cause shrinkage of the cartilage. For some with strong genetic predilection, arthritis begins at a younger age, the cartilage damage speeds up if you didn’t recognize the signs and symptoms earlier on. Making sure you are regularly active and maintaining optimal weight are crucial to delaying cartilage damage at this stage.
The risks of regular physical activities such as running should be weighed against the tremendous benefits of this activity to the other body systems. Running has been shown to decrease the risk of cardiovascular disease, diabetes mellitus, and depression. This kind of physical activity has also been shown to help with weight control, to improve bone density, and to decrease mortality.
Based on the existing evidence, moderate running is not associated with higher incidence of arthritis in healthy people and it may even work to facilitate healthier joints.