A new Indian study has found a significant association between overall diet quality and rheumatoid arthritis (RA), with people diagnosed with the autoimmune condition showing less varied diets, lower micronutrient adequacy and greater dietary inflammatory potential than healthy participants. The research was conducted by scientists from the ICMR-National Institute of Nutrition (ICMR-NIN), Hyderabad, and collaborating institutions.
The findings come from a case-control study involving 615 adults, including 301 people with newly diagnosed rheumatoid arthritis and 314 healthy controls. Researchers assessed participants' eating patterns using measures covering dietary inflammation, food-group diversity and the adequacy of important micronutrients.
Higher inflammatory potential seen among RA patients
One of the study's key measures was the Dietary Inflammatory Index (DII), which estimates the inflammatory potential of an individual's diet.
The median DII score was 2.18 among participants with rheumatoid arthritis, compared with 0.37 in the healthy control group. Researchers found that every one-unit increase in the DII was associated with a 17% increase in the adjusted odds of rheumatoid arthritis.
The results suggest that dietary patterns with greater inflammatory potential may be associated with RA risk. However, the study design cannot establish that such diets directly cause the disease.
Dietary variety was lower
Researchers also examined dietary diversity, which reflects how many different food groups are included in a person's diet.
Only 50.2% of participants with rheumatoid arthritis had a high dietary diversity score, compared with 74.2% of healthy controls. A one-unit increase in the diversity score was associated with a 27% reduction in the adjusted odds of rheumatoid arthritis.
The researchers also observed differences in overall micronutrient adequacy. Median adequacy was 18.9% among the RA group, compared with 32.9% among controls. A 10% increase in micronutrient adequacy was associated with a 12% reduction in the odds of rheumatoid arthritis.
What the findings mean
Rheumatoid arthritis is a chronic autoimmune disease in which the immune system attacks the body's own tissues, particularly the joints. Diet is only one potential factor among several that can influence health and disease risk.
The researchers emphasise that their findings should be interpreted as an association rather than evidence of a direct cause-and-effect relationship. Longer-term studies and controlled dietary interventions would be needed to determine whether improving diet can actually reduce the risk of developing rheumatoid arthritis or alter its progression.
Why dietary diversity matters
The findings add to growing research examining overall dietary patterns rather than focusing only on individual nutrients. A varied diet can help provide a broader range of essential nutrients, while dietary quality may also influence inflammatory processes in the body.
The ICMR-NIN has separately highlighted dietary diversity as an important part of nutrition research and public-health strategies in India.
For now, the study's main message is not that a particular food causes or prevents rheumatoid arthritis, but that overall nutritional quality may be an important factor worth investigating further in relation to autoimmune health.
