The mysterious rise in knee osteoarthritis

The mysterious rise in knee osteoarthritis – Harvard Health Blog – Harvard Health Publishing

Osteoarthritis is the form of joint disease that’s often called “wear-and-tear” or “age-related,” although it’s more complicated than that.

While it tends to affect older adults, it is not a matter of “wearing out” your joints the way tires on your car wear out over time. Your genes, your weight, and other factors contribute to the development of osteoarthritis.

Since genes don’t change quickly across populations, the rise in prevalence of osteoarthritis in recent generations suggests an environmental factor, such as activity, diet, or weight.  

To explain the rise in the prevalence of osteoarthritis in recent decades, most experts proposed that it was due to people living longer and the “epidemic of obesity,” since excess weight is a known risk factor for osteoarthritis.

Studies have shown not only that the risk of joint disease rises with weight, but also that even modest weight loss can lessen joint symptoms and in some cases allow a person to avoid surgery.

But a remarkable new study suggests there is more to the story.

Challenging a common assumption

Researchers publishing in the Proceedings of the National Academy of Sciences examined skeletons from people who had died and donated their bodies to research.

Information regarding presence of knee osteoarthritis, age at death, body mass index (BMI), cause of death, and other data were compared for more than 1,500 people who died between 1905 and 1940 (the “early industrial group”) and more than 800 people who died between 1976 and 2015 (the “post-industrial group”).

A third group of skeletons obtained from archeological sites were also assessed for osteoarthritis of the knee.

They came from prehistoric hunter-gatherers living hundreds to thousands of years ago, and early farmers living between 900 and 300 BP.

BMI could not be determined for these individuals, but gender could be determined and age was estimated based on features of their skeletons.

The findings were intriguing:

  • The prehistoric skeletons and early 1900s cadavers had similar rates of knee osteoarthritis: 6% for the former and 8% for the latter.
  • With a prevalence of 16%, the more recent skeletons had at least double the rate of knee osteoarthritis as those living in centuries past.
  • Even after accounting for age, BMI, and other relevant information, those in the post-industrial group had more than twice the rate of knee osteoarthritis as those in the early industrial group.

the findings shake some long-held assumptions and make the rise in osteoarthritis in recent years more mysterious than before.

So what?

These findings call into question assumptions about the reasons osteoarthritis is becoming more common. And they suggest that slowing or reversing the dramatic increase in obesity in recent years may not have as much of an impact on knee osteoarthritis as we’d thought.

Finally, if longevity and excess weight do not account for the rising rates of knee osteoarthritis, what does?

The list of possibilities is long, and as suggested by the authors of this study includes:

  • injury
  • wearing high-heeled shoes (yes, there is at least one study suggesting that the altered forces in the knee among those wearing high-heeled shoes might contribute to the development of osteoarthritis)
  • inactivity
  • walking on hard pavement
  • inflammation (worsened by inactivity, modern diets, and obesity)

The bottom line

As is so often the case in medical research, this new study raises more questions than it answers.

We’ll need a better understanding of why and how osteoarthritis develops before we can prevent it or improve its treatment.


6 thoughts on “The mysterious rise in knee osteoarthritis

  1. Kathy C

    I read the comments on the Article, including the ones about Statins, The Pharma Industry would not want them to study that connection. They want to keep it anecdotal. It does not look like these online health pages do much to improve health, they tend to revert to anecdotal stories, oddball “cures”, and a few believers, peddling “Alternative Medicine.” These “Studies” are limited by design, to create room for speculation, and pseudo science. Considering the costs of OA, and the limitations it causes in people lives, we should be further ahead in the research. Instead we have this kind of irresponsible health journalism, where anything goes.

    They immediately blame obesity, which is in many cases due to the inaction, from the OA in the first place. That way they can blame the patient, and get the public to ignore this, until it happens to them. They have to keep all of those big box Store workers in the dark about their risks, since they will not have insurance or healthcare, when it catches up to them.

    Liked by 1 person

      1. Kathy C

        I have been following how they write about these studies and research. The Articles are always vague, misinterpret the findings, and over sensationalize the meaning. This is by design, in order to keep the public baffled, or confused, and lead the general reader to a forgone conclusion based on bias. It is really no wonder there is a “War on Science.” One would expect an “Expert’ to weigh in on these online marketing and speculation nonsense sessions, but it rarely happens. What is truly astounding is the insertion of pseudo Science and nonsense in credible appearing sources. Things like this, Of course the most ridiculous, and outlandish is the most shared. They do not discuss the economic variables associated with some of these claims. This one takes the cake though,
        Cold Water Plunge a Natural Remedy for Postop Pain?
        This Anecdotal Story of one guy, who they claim was cured after Cold Water Exposure, gets equal exposure to actual science based articles. I wonder what happened to the others they tried that with? I doubt those outcomes will get written about. It is really scary what the internet, and so called Medical Science has devolved into.

        Liked by 1 person

        1. Zyp Czyk Post author

          Yes, there are countless ways to corrupt research. No matter the findings, researchers can design, count, and conclude in ways that support the pre-determined solutions.

          They should force researchers to do studies on hypotheses they do NOT agree with.


          1. Kathy C

            That would be a great idea! The American Psychological Association is trying to make Psychology a STEM Program in college! So the same people who are getting funding to “prove” mindfulness and other nonsense works, want to make their field appear on the level with real science. They are believing their own hype.
            Get a load of this! Each self referencing article, points to another small “Study” with Non specific pain, and clear flaws to back up their certainty.

            There is nothing about compassion in the article. it is very possible that the way that the APA has redefined Pain, and made it a “Psychological Issue, has made sure there is no empathy. We see the apathy and lack of compassion every time we turn on the News. Even Children being deprived, tortured or killed is explained away, or their stories used to illustrate a narrative that does nothing to improve anything. I hate to say it, but I think we have a nation of Pod People. The one thing the APA is not Studying is their role in current affairs, they choose to “Study” more profitable, self promoting issues. Mindfulness and the Happiness Movement both rely on disciples that spread the nonsense like multi level marketers. It is not about real research, it is about profiting with speaking engagements and books, like spreading the gospel.

            Liked by 1 person

            1. Zyp Czyk Post author

              In that APA article, what are they even talking about with “the problem of inconsistent recognition of psychology as a core STEM discipline”?!?

              That’s Absurd! Psychology is a “social” science and works with variables that cannot be measured with precision, like you can with physical objects. It makes no sense to “recognize” it as a STEM discipline – or use “psychological” treatments as a real fix for real pain.

              I’ve tried all the methods suggested in that Psych Today article and they were intriguing, but they did not relieve my pain one bit. Focusing on my body made the pain worse.


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