Published research on joint ageing · Read this before you buy another jar
No new supplement. No waiting half a year to notice something. A free five minute check that shows which signals in your own answers speak loudest.
"I'm just worn out. That's it."
Say that sentence out loud.
It sits close to what you think when you have to stand still for a moment at the top of the stairs. Or when your fingers are stiff in the morning as you pick up your coffee.
I am Jesse van der Velde. Not a guru and not a doctor. I study and share what published research says about how a body ages. I have been testing that on myself and with the people I guide for more than fourteen years.
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"Wear and tear" means used up. Too many years, too many stairs, too much tennis in your thirties.
If the material (the substances in your joints) has run out, the next step is obvious. Spare the joint. Top the material up. Buy the jar with the knee on the label.
That is how the shop is laid out: building materials in powder form, with a whole industry built around them.
There is one problem in that story.
Your cartilage is living tissue, maintained by cells that build the tissue up and clear away damaged parts. Below, I call that work "joint maintenance".
The research of the past decade points to those cells. The material comes only after that.
Maybe you think: "Well, that is just age."
But that is not true.
In 2016, three researchers led by Richard Loeser published a study on what growing older does to joints.¹
What was studied: the mechanisms through which ageing contributes to joint complaints.
How: this is a meta study. No trial of their own and no participants. The authors describe no search strategy and no selection criteria, and what they discuss is largely about cartilage.
The findings: five changes that run at the same time in an ageing joint and together produce one outcome, more breakdown and less repair.
Read that list again. Nowhere does it say "used up". The cells that did the joint maintenance change their behaviour.
The authors add themselves that growing older and joint complaints are closely linked, but are two separate processes. So growing older does not produce those complaints by itself.
There is a separate review article about that oxidative stress. Henrotin, Kurz and Aigner published in 2005 on reactive oxygen species, molecules that form in every cell as soon as that cell uses oxygen.²
What was studied: what oxygen and those molecules do to cartilage cells.
How: a systematic search in Medline, after which the authors set out the published research on cells in the laboratory and in living tissue. Here too, no patients.
The findings: the same molecules do two opposite things, and the amount decides which of the two. At normal levels they belong to the ordinary jobs of the cartilage cell: activating the cell, cell division, and reshaping the tissue around it, which involves both building up and breaking down. As soon as production becomes greater than what the cell clears away, what the authors call "oxidative stress" sets in, and those same cells are damaged.
Which side your own body is on is not something you can feel from the inside.
The authors are honest about how far that reaches: they themselves call the precise role of oxidative stress in cartilage breakdown still unclear.
For twenty years you were handed a story you could do nothing about. Cell behaviour does respond to load, muscle strength and weight.
That makes the process something you can tackle.
Does this sound familiar? Take the free check now.
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654.1 million. In 2020 a meta-analysis by Cui and colleagues appeared: 88 population studies with 10,081,952 participants between them, searched in PUBMED, EMBASE and SCOPUS up to and including 4 April 2020. Long-term knee complaints occurred in 22.9 per cent of people aged 40 and over, about 654.1 million worldwide.³
That number is a calculation and not a count: the authors put a 95 per cent confidence interval with it, of 565.6 to 745.6 million. It says how many people are walking around with it, and nothing about what is going on with you.
11th of 291. The Global Burden of Disease programme published the calculation by Cross and colleagues in 2014. They gathered figures by age and sex through systematic reviews, and ran those through a model per country for 1990 and 2010. Of the 291 conditions counted, hip and knee complaints stood 11th in 2010 among the largest causes of disability worldwide.⁴
The authors note themselves that problems in their method make it very likely that the true burden has been underestimated. That 11th place is a lower limit.
1.69 times. The same 2020 meta-analysis found long-term knee complaints 1.69 times as often in women as in men (95 per cent confidence interval 1.59 to 1.80).³
Are you a woman over fifty? Then that difference was already there in the figures, and nobody told you.
You know your own version of this. The version I heard from older family around me came out of a hotel where we were with the family: two flights of stairs to breakfast, and over the first six steps my grandmother moved stiffly and slowly.
"I'm just worn out" turns two slow minutes into a verdict on the rest of your life.
Then you adapt. You take the lift. You stop saying yes to the walk.
What you felt is real. For that verdict there is no evidence.
The research describes a process that is running. And with a process, you can work out where it stands.
1. The jar of building blocks.
The reasoning was supply: the material is gone, so eat the material. There is a kernel of truth in that. It helps. But it is not the whole story, you have to look further as well.
In 2006 Bello and Oesser looked at the literature on collagen hydrolysate: a search in PubMed up to May 2006, plus conference abstracts and German-language articles they considered relevant themselves. So not a systematic review. They found four open and three double-blind studies. Collagen hydrolysate is absorbed in the gut and builds up in cartilage, and cartilage cells in the laboratory go on to make more building blocks because of it (p less than 0.05 against untreated cells). In those seven studies it proved safe, and in some men and women it gave improvement on some measures of pain and function.⁵
Only, the authors add themselves that many of those studies did not state whether their result was statistically significant. They call their conclusion a reason to consider it, and not proof that it works.
So you were not foolish to buy it. It is just that a jar gives you no answer to the question of which of those five plays the biggest role in you.
2. Taking it easier.
If the problem is wear and tear, rest makes sense. But be clear about what rest does and does not do. At that moment it takes the load away. It does not tell you which of the processes above speaks loudest in your case, and sparing a joint for a long time also takes away the load your muscles need.
In 2016 Briggs and colleagues wrote a report in The Gerontologist for the World Health Organization's 2015 world report on ageing. There are more than 150 kinds of conditions of the muscles, bones and joints. Their core point: painful complaints from these are strongly linked to being less able to move, and what follows is decline in functioning, frailty, less wellbeing and loss of independence.⁶
Rest leads to less movement, and that is exactly what this report points to as the problem. Note as well what it cannot say: there is no research of its own behind it, so it describes a direction and does not prove that anything works.
3. "It's my age, there's nothing to be done about it."
Newman and colleagues followed 2,292 people aged 70 to 79, and published that in 2006 in the Journals of Gerontology. Here strength and muscle size were measured in the same people: strength with strength meters, size with a CT scan and a DXA scan. After that they kept track of who died. 286 people died over an average of 4.9 years. Strength was closely linked to death: for every standard deviation less knee strength, 38 newton metres, the chance of dying was 1.51 times as high in men (95 per cent confidence interval 1.28 to 1.79) and 1.65 times as high in women (1.19 to 2.30). Muscle size was not closely linked to death in this study.⁷
Correcting for muscle size barely changed the link with strength.
Nobody was trained. This is a group that was followed, so it holds a link and not a cause: within the same age group, strength was linked to mortality, and muscle size was not.
4. Waiting the year out.
Give it time, see how it develops. But a process with a direction does not pause while you wait. The report in The Gerontologist points in one direction: less movement, and after that a loss of independence.⁶
Four answers, one shared problem: not one of them looked at what is going on in your case.
The story about wear and tear is not right, so neither is the approach that followed from it. That approach has failed. You have done nothing wrong. It can be done differently.
This is the heart of it. If joint ageing is five processes running at the same time, "which jar" is no longer a useful question.
The question becomes: which of those five plays the biggest role in me right now?
Inflammatory activity that keeps going asks for something different from a joint that is loaded wrongly because of too little muscle strength. From the inside, both feel like the same stiff morning.
That is new. The 2016 review article listed those five processes side by side and made them nameable.¹
What was not there: a way to hold your own situation up against that list.
On one condition. An analysis like that has to be about you: your symptoms, your pattern, laid question by question alongside those processes. A general list of joint tips does not tell you which of those five plays the biggest part in your case.
BioProfile has built that first step. A scientifically validated questionnaire, five minutes, free and with no account.
You answer questions about your body and your daily life. After that you see which signals in your profile speak loudly, and what the research says about them.
Not a medical examination. An analysis of your own answers. You use the outcome yourself, or you put it on the table with your doctor or your coach.
None of the four routes above started from your own situation.
You do the free check. Five minutes, no account, and there is nothing to buy.
Even if you do nothing with it, you have traded "I am just worn out" for an analysis of your own answers. That trade is worth five minutes.
And the next time you stop at the top of the stairs, you will know which signals in your profile speak loudest.
Do it while this page is still open. The process carries on as long as you wait.
Our scientifically validated questionnaire gives you answers
The scan is not a medical examination. It is an analysis of your own answers. If complaints persist, consult your doctor.
