Rheumatoid Arthritis: Whole-Food Diet May Be Protective

TOPLINE:
Middle-aged adults who consume more ultra-processed foods have an elevated risk for rheumatoid arthritis (RA) that is mediated in part through circulating biomarkers.
METHODOLOGY: 
Investigators conducted a retrospective cohort study of 207,012 middle-aged adults without RA from the UK Biobank who completed 24-hour dietary recalls.
Foods and beverages were classified as (1) unprocessed or minimally processed foods, (2) processed culinary ingredients, (3) processed foods, or (4) ultra-processed foods (eg, soft drinks, sweet or savoury packaged snacks, reconstituted meat products, pre-prepared frozen dishes).
The main outcome was the incident RA based on hospital diagnoses.
TAKEAWAY:
Overall, 0.9% of participants received an RA diagnosis during a median follow-up of about 12 years.
Relative to peers in the lowest quintile of ultra-processed food consumption, participants in the highest quintile had a 17% greater adjusted risk for RA.
The risk rose across quintile (P < .05) and increased by 6% with each standard deviation increase in ultra-processed food intake.
Mediation analyses suggested that inflammatory, lipid, and liver enzyme biomarkers explained 3.1%-14.8% of the association between ultra-processed food intake and RA risk.
Findings were similar regardless of participants’ age, sex, body mass index, smoking status, household income, and healthy diet score.
IN PRACTICE: 
“Lower [ultra-processed food] consumption is recommended to reduce RA incidence,” the authors wrote, noting that up to half of the food consumed in the United Kingdom now falls into the ultra-processed category. “Dietary guidelines should prominently feature the detrimental effects of [ultra-processed foods], and recommendations to curtail their consumption should be integrated into public health initiatives, to mitigate the risk of RA,” they added.
SOURCE:
The study was led by Haodong Zhao, Soochow University, Suzhou, China, and was published online in the American Journal of Clinical Nutrition. 
LIMITATIONS:
Limitations included possible recall and social desirability biases, potential residual confounding, and uncertain causality of the observed associations.
DISCLOSURES:
The study was funded by grants from the National Natural Science Foundation of China and other institutions. The authors reported no conflicts of interest.
 
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