Will nightshade foods make my arthritis worse?

I've recently been diagnosed with rheumatoid arthritis and am on medication to dampen my immune system. A friend says nightshade foods can make the inflammation worse. What's your view?

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A The nightshade family contains over 2,000 varieties of plants, but only a few of them are eaten as food. Some such as belladonna (or deadly nightshade) are poisonous.

The edible ones include potatoes, tomatoes, peppers, and aubergines, also several spices are derived from them such as chili powder and paprika. They are generally very nutritious, containing vitamins A and C, and are also a good source of fibre.

But they all contain very small amounts of alkaloid chemicals, which some have suggested can promote inflammation, and may worsen symptoms of auto-immune illnesses, such as rheumatoid arthritis.

Many people with these illnesses stop nightshade foods and claim their symptoms improve yet there isn't good research to back this up, and no evidence that nightshades can make arthritis worse.

That said though, some people do react to foods, and if you think that eating nightshade foods could be making your joints worse you could try excluding them from your diet for four weeks and keep a diary to see if there is any change in symptoms.

After this, start re-introducing them one at a time, and again, keep a symptom diary. If the nightshade foods did make your pain worse, you can continue avoiding them, but make sure you eat other foods that provide the nutrients they contain, such as citrus fruits for vitamin C, and sweet potatoes for A, together with lots of green leafy vegetables.