Millions of arthritis sufferers in the UK have been cautioned about two everyday fruits that could exacerbate their condition. Arthritis, which can cause pain, swelling, inflammation and mobility issues, currently has no cure, but symptoms can be managed.

Diet can significantly impact the condition, either alleviating or worsening it. The Physicians Committee has highlighted certain foods as “pain triggers”, including apples and tomatoes.

The report stated: “While genetic factors are important, studies show that lifestyle factors, including diet, play a role. If you have rheumatoid arthritis, a diet change could help you, and perhaps even eliminate your pain entirely. In research studies, many people who cut out certain trigger foods find that their pain improves or goes away. When those foods are gone, so is the inflammation. A survey of more than 1,000 arthritis patients revealed that red meat, sugar, fat, salt, caffeine, and nightshade plants most commonly worsen the condition.”

Both apples and tomatoes contain solanine, a glycoalkaloid poison found mainly in nightshade family species. A study published in the Arab Journal of Nuclear Sciences and Applications in 2013 explored the link between solanine and arthritis.

The study suggests: “Solanine is a toxic compound produced in nightshades family such as potato, tomato and eggplant when exposed to light. The current study was carried out on 18 female postmenopausal albino rats to investigate the effect of solanine on the symptoms of rheumatoid arthritis. The data of the present study showed that old age and postmenopausal suffering from arthritis and joint swelling must eliminate or avoid the nightshades plants to alleviate the joint pain and also decrease the destruction of the tissues.”

However, the validity of this claim has been disputed by other health organisations. The Arthritis Society Canada advised monitoring personal reactions to foods that contain solanine, reports the Mirror.

In related news, researchers have recently discovered that a medication which controls blood sugar levels in type 2 diabetes can also benefit patients with certain autoimmune diseases. The drug, Canagliflozin, affects T-cells – which are typically involved in fighting infections but can erroneously attack healthy tissue in autoimmune conditions.

Therefore, Canagliflozin’s action on these cells could help over 400,000 people in the UK who suffer from rheumatoid arthritis and another 50,000 with lupus.