A new study reported in Nutrients has identified some of the potential food triggers of arthritis, while an unrelated study published in Immunity has revealed a cell type that could help predict or prevent flares of the disease.
In Nutrients, researchers analyzed thirty different studies conducted between 2000 and 2024 that included a total of about 10,000 rheumatoid arthritis patients. This work showed that low to moderate alcohol consumption, and increased consumption of cereals, fruit, and oily fish were associated with a reduced risk of rheumatoid arthritis. The intake of tea and coffee, however, was linked to an increase in arthritis risk.
Oily fish and vitamin D could have some protective effect against arthritis. Previous researchers have also shown that low levels of vitamin D have been associated with an increase in arthritis risk. But the results are also nuanced. For example, while moderate alcohol intake may help prevent arthritis, excess alcohol consumption can increase it, and those findings may not hold true for every person. In other words, the anti-arthritic influence from alcohol consumption disappeared once a person consumed at least four pints of beer or cider every week, or around three and a half glasses of wine.
The overall increase in risk from tea or coffee drinking was also small at about four percent, but that increased by an additonal four percent for every extra cup per day.
"More research will help us pinpoint exactly why these foods have the effect we have observed and develop tailored nutritional advice for people living with rheumatoid arthritis and other autoimmune diseases," said senior study author Professor Janet Cade of the University of Leeds.
In the journal Immunity, scientists assessed tissue samples from rheumatoid arthritis patients with a technique called spatial transcriptomics. This can reveal when and where genes are being expressed in tissues, whether healthy or diseased. The video below outlines the spatial transcriptomics technique.
The work showed that dendritic cells are different in arthritis patients who are having arthritis flares, and those who are not having flares. Those at risk of flares have dendritic cells in their blood weeks prior to the flare; this may indicate that dendritic cells in the blood work as a biomarker of oncoming flares, or a potential treatment target that may reduce arthritis flares.
Dendritic cells can help control the activity of other cells. In arthritis patients who are in remission and not experiencing flares, dendritic cells help suppress the inflammatory effect of T cells. But during active arthritis, the dendritic cells seem to move from the blood to the joints, leading to inflammation and joint damage, as the T cells are free to attack the tissue.
"We hope this research is the first step to find new ways to help more arthritis patients and to optimize their management, letting them stay symptom free and remain in remission after their therapeutic journey," said co-senior study author Professor Stefano Alivernini of the Fondazione Policlinico Gemelli IRCCS, among other appointments.
Sources: University of Leeds, Nutrients, University of Glasgow, Immunity
