Why diet is as important as exercise for osteoarthritis, according to a rheumatologist

Here, Holden explains how diet can help protect against osteoarthritis – or you can skip ahead to what to eat and what to avoid.

“If you imagine pulling the leg off a chicken, the grisly bit is the cartilage,” says Holden. “It’s a shock-absorber that protects the joint.

“We used to think osteoarthritis was just a disorder of the cartilage, that it just ‘wore out’, so you had bone on bone, causing pain and stiffness.” What’s more, it was assumed that the condition was inevitable with age. “We now know there’s much more to it than wear and tear,” she adds. “It’s now considered a more inflammatory process. There’s inflammation in the joint that affects the muscles, the lining of the joints, the ligaments and nerves.

“One of the body’s responses to that inflammation is to make new bone, which can contribute to pain and stiffness. You can sometimes see people with knobbly finger bones or swelling of the knee because of new bone formation.”

That’s not to say that other factors don’t play a role in the development of osteoarthritis. “Sometimes it’s brought on by trauma, when something goes wrong with the mechanics of the joint due to an injury, for example, during football or skiing.

“Other times, it’s due to increased weight bearing – more load on the joints – which is why it’s a problem for people that are overweight, especially [for] their knees and hips.”

If it is healthy, the gut microbiome – the trillions of bacteria, fungi and viruses that live in our digestive system – can help bring down the inflammation that is known to trigger arthritis.

“Your microbiome talks directly to the immune system,” Holden explains. “They’re very, very close together – there is just a fraction of a millimetre between the microbiome and the immune cells in the gut.”

The immune system regulates inflammation in the body and takes cues from the microbiome. “If the microbiome is healthy, there are anti-inflammatory molecules that are released within the gut,” she explains. These are called short-chain fatty acids, which are known to bring down inflammation and have also been linked with easing pain.

“So by eating healthy food, you encourage the good bacteria which feed on that food, and then they release those anti-inflammatory substances that will help regulate the immune system that can drive inflammation.”

Leeks, bananas and oats

Leeks, bananas and oats may sound like a disparate list of food, but they are united by the fact that they’re a good source of inulin, a type of prebiotic fibre.

The body can’t absorb fibre in the same way it absorbs carbohydrates and protein, but the microbiome feeds on it as it passes through our digestive system. “The gut microbiome loves it,” Holden says.

One study, from researchers at the University of Nottingham, recruited 117 adults with knee osteoarthritis who tried different remedies. One group, given daily supplements containing inulin for six weeks, reported less knee pain and also improved grip strength.

“It’s really interesting,” Holden says. “That pain reduced and grip strength increased suggests inulin has an anti-inflammatory effect in general, which would affect the hand joints, as well as the knees.”

However, she urges people to consume a variety of sources of inulin. “Eating one of these foods is no good, you need a whole broad balance of them to encourage different bacteria.” Other inulin-containing foods include chicory, Jerusalem artichokes, garlic, onions, asparagus and barley.

Blueberries, peppers and tomatoes

“It’s all about eating a colourful diet, really,” Holden says. It’s no secret that fruit and vegetables are good for us, but ensuring you’re including plenty in your diet, including a variety of colours, may ease osteoarthritis.

“They can be good for inflamed joints, especially those with antioxidants in them – colourful foods like blueberries, red cabbage, peppers, tomatoes,” she says.

In particular, research has suggested that cherries may help, as they contain anthocyanins, a type of antioxidant with anti-inflammatory properties, while studies have also linked broccoli with reducing pain and improving function.

“There’s a lot of nonsense written about avoiding tomatoes because they are nightshades,” she notes. “Lots of people used to think they were bad for inflamed joints, but it’s actually the opposite.”

Mackerel, salmon and herring

“Omega-3 fatty acids are very important for joint health,” Holden says. “They are present in fish.” While they have been more extensively studied for their role in improving heart health, research suggests they ease pain and improve stiffness.

The NHS recommends eating at least two portions of fish per week, one of which should be oily. Mackerel, salmon and herring all count as a type of oily fish and are potent sources of omega-3s.

Holden recommends sticking to the NHS-recommended intake. “We don’t want too much fish because you might get too much mercury,” she says. “It’s all about balance.”

If you’re struggling to get enough fish in your diet, there are omega-3 capsules, she continues. “However, dietary sources are better than anything you get in pill form.”

Biscuits, cakes and cereal

“If you’re eating a lot of refined or processed food made with sugar and white flour, that’s not brilliant for the microbiome,” Holden says. Unfortunately, biscuits, cakes, pastries and many breakfast cereals fall into this category.

“It’s not going to do any harm to have them occasionally,” she says. “But if you constantly have what we would think of as junk, it’s not going to be good for us.”

“The problem is that, unlike fruit, vegetables and wholegrains, these foods are not anti-inflammatory. They’re not going to encourage the healthy bacteria that we need.”

Sugary foods are also easy to over-consume – they are tasty and calorie-packed – so can lead to weight gain, which is known to exacerbate osteoarthritis, she says.

Processed meat, butter and pies

Osteoarthritis patients are more likely to have raised cholesterol levels, and research suggests that this is linked to the development of the condition, while lowering cholesterol is thought to improve osteoarthritis.

“Lots of people with osteoarthritis who are overweight will have high cholesterol and they’re often eating unhealthy diets,” Holden says.

“Moving away from more saturated food [such as processed meat, butter and pies] and going towards fish and plant-based eating is the best way to go.”

Turmeric capsules

Turmeric is the top-selling supplement in the UK, and research has suggested it could ease arthritis because it contains curcumin, a polyphenol with anti-inflammatory and antioxidant properties.

“But you need to eat absolutely masses of it to get an anti-inflammatory effect,” Holden says. “You cannot possibly get that enormous amount in a capsule.” However, there’s no harm in adding turmeric to meals like homemade curries, she explains. Grinding in black pepper will boost the amount of curcumin the body can absorb.