Foods for joint health: what helps and what does not

Which foods help your joints?

No single food can strengthen a joint on its own. What helps is an overall pattern: protein spread throughout the day, fruit and vegetables every day, oily fish regularly, olive oil and pulses. And an amount of food that allows you to maintain a healthy weight. In essence, this is the anti-inflammatory diet, an eating pattern you can sustain over time. You can try it for three months to see whether it helps you.

Within that set, three pieces carry more weight when you are concerned about your joints. They are weight, protein with vitamin C and omega-3.

How much does weight affect knees and hips?

A lot, and it is what has the most backing. Knees and hips bear body weight with every step. When climbing stairs, jumping or running, that load multiplies.

That is why osteoarthritis guidelines include weight management through diet among the core treatments for knee osteoarthritis, alongside education and exercise [1]. The UK NICE guideline adds that, with osteoarthritis and overweight or obesity, any weight loss probably helps [2]. And that losing 10% of weight probably helps more than losing 5% [2]. See “Osteoarthritis and diet”.

This does not mean crash dieting. It means eating a little less than you use, consistently, with enough protein and strength exercise. This way you do not lose muscle, which supports and protects the joint. If you do sport, excess weight adds to the impact of every jump and stride.

Protein and vitamin C to care for tendons and cartilage

Tendons, ligaments and cartilage are made largely of collagen, a protein your body makes with amino acids from what you eat. To make it, it needs enough protein and vitamin C. In fact, the European Union permits claiming that vitamin C contributes to normal collagen formation for the normal function of cartilage and bones [3].

Protein is found in fish, eggs, meat, dairy products, pulses, tofu and nuts. It does not need to come mainly from meat. Combining several sources across the week covers the same and leaves room for more fish and more pulses. If you train regularly, needs are between 1.2 and 2.0 g of protein per kilogram of body weight per day, spread across meals [4].

Vitamin C is easy to cover with an orange, a couple of kiwifruits, a handful of strawberries or raw red pepper in a salad. As it is lost with heat, it is best to eat part of the day’s fruit and vegetables raw.

For the bones that form the joint, calcium and vitamin D matter. Calcium is in dairy products, small fish eaten with their bones and pulses, and vitamin D is made with some sun outdoors. The same European regulation states that both help maintain bones in normal conditions [3]. From age 25, EFSA sets the general calcium reference for adults at 950 mg a day.

Does oily fish help with joint inflammation?

The omega-3 in oily fish is part of an anti-inflammatory eating pattern and has a place in yours. It is best not to ask more of them than they give, because they do not switch off an injury or replace a treatment. Which fish and seeds provide more, and how many times a week to have them, you have in our guide to foods rich in omega-3.

Do collagen, gelatine or bone broth help?

This is one of the questions that reach us most often in clinic, and the honest answer is that they help less than advertising promises. The collagen you eat does not travel whole to your knee. It is digested like any other protein, and the body uses its pieces wherever it needs them.

A review analysed fifteen trials in which collagen was given alongside exercise, mainly to recreational athletes [5]. It saw improvements in pain and in joint function. But its authors recognise that groups were small and mechanisms unclear, and call for larger studies [5]. They are interesting signals, with still limited evidence.

Gelatine, bone broth or ham hock provide protein with the same components as collagen. They can be part of your diet if you enjoy them, but there is no reason to force them or spend on collagen products before covering the basics.

What mistakes do we see in clinic?

These pitfalls come up often, and nearly all stem from looking for a shortcut.

• Starting with the tub. The NICE osteoarthritis guideline asks not to offer glucosamine to treat osteoarthritis, because there is no solid evidence that it works [2]. If you are considering this or another supplement, discuss it beforehand with your doctor or a dietitian-nutritionist.
• Looking for the food that fixes everything. Neither onion, nor garlic, nor pineapple, nor papaya repair a joint. They are good foods, and that is enough.
• Drinking a larger amount of water to ‘lubricate’. Staying well hydrated matters. According to EFSA, total daily water, including that from food, is 2 L in women and 2.5 L in men. But there is no evidence that drinking more than you need improves joint fluid.
• Eating too little when you are off training due to an injury. It is a frequent gesture to ‘compensate’ for not training. Repairing tissue also needs energy and protein.

If the pain comes from arthritis

If the pain is due to rheumatoid arthritis, psoriatic arthritis or another inflammatory disease, nutrition has other priorities. We explain them in the diet for rheumatoid arthritis. In osteoarthritis and sports injuries, what you have read here is the starting point. In any case, nutrition accompanies the treatment prescribed for you and does not replace it.