The NIN study found a strong link between diet quality and rheumatoid arthritis

Adults suffering from rheumatoid arthritis (RA) tend to have less varied diets, lower adequacy of micronutrients and eating habits that may promote inflammation compared to healthy individuals, researchers from the ICMR-National Institute of Nutrition (ICMR-NIN) here in Hyderabad said.

Rheumatoid arthritis is a long-term autoimmune disorder in which the body’s immune system mistakenly attacks healthy tissues, especially joints, leading to pain, swelling and reduced mobility. Although genetic and environmental factors are known to contribute to the disease, the role of dietary habits in the Indian population has not been extensively studied.

In this case-control study involving 615 adults aged 18 to 55 from Hyderabad, including 301 newly diagnosed RA patients and 314 healthy controls, researchers assessed participants’ eating habits using a validated 131-item food frequency questionnaire.

The study examined three key indicators of diet quality: dietary inflammatory potential, as measured by the Dietary Inflammatory Index (DII); dietary diversity, assessed through the Dietary Diversity Score (DDS); and micronutrient adequacy, assessed using mean probability of adequacy (MPA).

The results revealed that participants with RA had a significantly higher mean DII score of 2.18 compared to 0.37 in healthy controls, suggesting that their diet had greater inflammatory potential. Dietary diversity was also poorer in people with the disease.

Only 50.2% of RA patients had a high dietary diversity score compared to 74.2% of healthy participants. Similarly, micronutrient adequacy was significantly lower in the RA group, with a median MPA of 18.9%, versus 32.9% among controls.

Each one-unit increase in the dietary inflammatory index was associated with a 17% increase in the odds of having RA after adjusting for age, sex, and body mass index. In contrast, each one-unit increase in dietary diversity was associated with a 27% reduction in the odds of the disease, while each 10% increase in micronutrient adequacy was associated with a 12% lower odds of RA.

The findings point to the importance of looking at overall diet quality rather than individual nutrients when understanding chronic inflammatory conditions,” said study leader Devraj J. Parasannanavar. Dietary diversity and adequate intake of essential micronutrients are important components of a healthy diet and warrant further investigation in relation to inflammatory diseases, he added.

ICMR-NIN Director Bharati Kulkarni called for long-term intervention-based studies to determine whether dietary improvements can help prevent or modify RA. The researchers also emphasized that while the study does not prove that a poor diet causes RA, it highlights a significant association that deserves further research, according to the press release. The study was published in the international peer-reviewed journal – Nutrients.

Published – 06 Oct 2026 20:29 IST