There is compelling evidence that nutrition can play a role in managing the symptoms of osteoarthritis. How much it can help is individual to each situation. It is certainly an area worth looking at though.
Osteoarthritis is multifactorial. It involves inflammation, loss of cartilage and breakdown of bone. Understanding this allows us to focus on what areas need to be managed for nutrition to have an impact.
From another perspective though, what we really care about is pain and function. While understanding the pathology is helpful, the goal is still a reduction in pain and an improvement in function.
Any nutrition intervention should be analysed more on its ability to help those things in practice, rather than theoretical mechanisms alone.
This post will cover a broad range of topics in relation to how nutrition can help with the management of osteoarthritis.
Weight-Loss
Weight loss has consistently been demonstrated to help osteoarthritis management on average.
This is due to a variety of reasons.
- Obesity is linked with higher levels of inflammation.
- Higher body weight means more stress on joints such as the knees.
- Metabolic factors such as high cholesterol and diabetes are linked with osteoarthritis. Weight loss often helps those conditions too.
Losing as little as 5% of body weight has consistently been shown to lead to improvements in pain and function.
Physical activity also has a lot of benefits for osteoarthritis. It can be a vicious cycle where the pain makes it more difficult to perform physical activity though. Potentially, a reduction in weight through dietary adjustments can make it more realistic to increase physical activity.
Collagen Supplementation
Theoretically, collagen supplements could help through the following mechanisms:
- Directly helping either delay the breakdown of cartilage or helping regrow cartilage.
- Helping to strengthen tendons and ligaments around the affected area.
A 2020 review of the evidence found that collagen supplements have promise, but the research is still mixed and relatively weak.
MRI footage has not shown any changes in cartilage, even in studies with positive findings. But still, there are studies that have found reductions in pain and stiffness, which is what we care about.
There are still massive gaps in the research. One gap is that there just is not enough research in general.
Another gap is that almost all of the studies use quite low dosages of collagen. The maximum that has been studied is 10g per day. Most studies have used less.
Meanwhile, for tendons and ligaments, the current consensus is 15-25g prior to a training/rehab session.
It is hard to say, but potentially the research would look more promising if higher dosages were trialled.
At a minimum, there is no major downside apart from the cost and effort of implementation. And there is potential upside if it does help.
Glucosamine, Chondroitin and MSM
Supplements such as glucosamine, chondroitin and Methylsulfonylmethane (MSM) have some weak evidence of benefit.
Glucosamine provides a small benefit in some studies and no benefit in others. The evidence is not strong enough that it should be a gold-standard recommendation. It is safe to take though and could potentially have a small benefit.
A review of the research on chondroitin found a small to moderate improvement in pain scores. This was found when used either alone or alongside glucosamine. On a scale of 0-100, the average improvement found was 8.
Research has also found MSM to outperform placebo. Similar to the other options though, the research is relatively weak and leaves a lot to be desired.
Some organisations suggest taking supplements like these for 6 months and discontinuing them if you do not see a difference.
Personally, my interpretation is slightly different. I think of them as things that probably help 1-3%. If something helps 1-3%, would you notice the difference? If you noticed the difference, it might be a placebo more than anything.
Omega-3
In individuals who either have osteoarthritis or are at risk, there is an inverse relationship between omega-3 levels and cartilage loss.
More omega-3 could delay this breakdown of cartilage.
Higher omega-3 intake is also linked with a reduction in inflammation.
Research on omega-3 supplementation and osteoarthritis has been mixed.
Specifically, dosages equivalent to ~1.5g of fish oil have shown some level of benefit.
This could be achieved through increasing oily fish intake, fish oil supplements or certain plant-based options.
Cholesterol
High cholesterol levels have been linked with osteoarthritis.
From one perspective, this could be looked at as if it is just linked to the body weight aspect. People at higher body weights average higher cholesterol.
But there is evidence that taking steps to reduce cholesterol can directly improve osteoarthritis.
One of the best examples of this is that statins have been shown to decrease the risk of developing osteoarthritis. Statins also reduce inflammation and decrease cartilage degeneration in osteoarthritis.
Taking some of the following steps to reduce cholesterol by an equivalent amount likely would have a similar effect:
- Decreasing body weight.
- Reducing saturated fat intake.
- Consuming/supplementing 2-3g of plant sterols per day.
- Reducing intake of dietary cholesterol if it is high.
Vitamin D
Vitamin D has mixed evidence for osteoarthritis.
Theoretically, it should help due to the benefits it has on inflammation and bone health.
When supplemented without context, it does not seem to help much.
From another perspective, vitamin D deficiency is clearly linked with an increased rate of cartilage loss and the risk of osteoarthritis.
Vitamin D deficiency is quite common too.
It makes sense to test your vitamin D status. If it is fine, I would not change anything. If it is low, I would recommend supplementing because:
- It is cheap and there is minimal downside.
- The link between low vitamin D status and an increase in cartilage breakdown is worth addressing.
- There are a lot of other benefits of having sufficient levels of vitamin D outside of osteoarthritis-specific stuff.
Anti-Inflammatory Style Diet
While this post has mostly focused on individual nutrients or supplements, the overall dietary pattern matters.
A great example of this is research showing that osteoarthritis rates are lower in those following a Mediterranean diet.
A Mediterranean diet can be defined in many ways, but it typically focuses on:
- High intake of fruits, vegetables, legumes, nuts, seeds, fish, wholegrains and extra virgin olive oil.
- Moderate consumption of dairy, poultry, eggs and red wine.
Anything not mentioned in that list is typically consumed infrequently in small amounts, if at all.
This type of eating is very micronutrient dense. It is high in polyphenols and is linked with reductions in inflammation which can help too.
There has been a lot of research done on the Mediterranean diet specifically. It is highly likely that a lot of these concepts could be applied to other dietary approaches as well.
Thoughts on Avoiding Things Such as Dairy or Nightshades
Avoiding foods such as dairy and nightshades are often recommended from the perspective of reducing inflammation.
The research does not support that standpoint.
As a starting point, the research has identified that dairy either has a neutral or positive effect on improving symptoms.
I am not trying to build a case for dairy. You can have a great diet, from a nutrition perspective, with or without dairy.
But I am highlighting that if dairy is detrimental for osteoarthritis, why do we not see that in the research?
There are anecdotal reports of decreased dairy intake helping. This is worth being aware of. But there are a multitude of flaws in overinterpreting individual results. I would instead focus on the hierarchy of evidence.
There is not much research on nightshades and osteoarthritis specifically. This topic has been looked at closely since at least as early as 1993. Not much research on the topic has been done since then though.
My interpretation is that researchers are not convinced enough by the link to spend time and resources on it.
Diets such as the Mediterranean diet contain both dairy and nightshades in moderate amounts and still lead to improvements in symptoms.
My thoughts are:
- It is unlikely that removing dairy or nightshades from your diet would improve symptoms unless it impacts other variables.
- If you are going to remove them, you can still adjust your diet and have a great diet without them. It just takes some planning and adjustments.
Practical Summary
Diet can help osteoarthritis in a lot of cases.
There unfortunately is no specific approach that leads to large-scale success in most cases.
A lot of the approaches mentioned here have the potential to improve symptoms. But there is no one food, supplement or strategy that leads to dramatic changes in symptoms by itself for most people.
Making dietary changes can help with the management of osteoarthritis. How much it helps will differ on a case-by-case basis though.
