We spend a lot of time on this blog discussing arthritis and specifically knee osteoarthritis (OA). Thus, we took interest in a study that determined the rates of knee OA are higher now than they were in the past 6,000 years! We thought you might find it interesting too.

To gather their data, the researchers examined over 2,500 skeletons of people over age 50 that were in museums or donated for medical research. These skeletons came from various places in the United States and were from people who lived approximately 6 years ago all the way to 6,000 years ago. This level of perspective was important because it allowed the researchers to study known risk factors, particularly age and obesity, under various conditions.

The researchers were surprised to find that 21st century humans had double the rate of OA as their ancestors. According to the study, only 8% of early humans and 6% of 20th century industrial-age workers showed evidence of OA. In comparison, 16% of Americans today showed evidence of OA. Thus, while older humans, especially those in the hunter-gatherer era as well as those in the early 20th century, tended to be more physically active and presumably harder on their joints, it seems this did not lead to a greater prevalence of OA.

Though the research team did not explore potential other factors that are driving the increase in OA prevalence, they guessed that it may be due to a lack of physical activity. Modern humans have become much more sedentary, which can negatively affect joint health. We have discussed in previous blogs how regular, low-impact exercise can help to delay the onset and/or reduce the symptoms of OA. So, it makes sense that the more active lifestyles of days past helped to keep early humans’ joints healthier.

What does this mean for you? Stay active! According to the CDC, physical activity can help you manage your knee OA. The Arthritis Foundations states, “The health of your knees depends on movement. Strong muscles support the joint and relieve pressure. Movement keeps tissues within the joint flexible, lubricated and replenished with nutrients that help healing.” Physical activity can also lead to weight loss, a key component in managing OA symptoms. Recent studies have demonstrated that a weight loss of 10% or more can lead to improvements in pain, function, and quality of life.