The Study
Ultra-processed food consumption and incident autoimmune-related hypothyroidism: A sex-stratified prospective analysis from the UK Biobank.
This study found that people who ate more ultra-processed foods were more likely to later get a thyroid problem, but it didn’t prove that the food caused the problem. It’s like noticing that people who wear red shoes often get colds — maybe red shoes are linked to colds, but maybe they just go outside more in winter.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
This study looked at what people ate and whether they later got a thyroid problem caused by their immune system attacking their own thyroid.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 567 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — for every 10 people eating lots of processed foods, about 1 extra person might develop this thyroid condition over 11 years, especially if they're a woman on hormone therapy.
- 2People who ate more than 20% of their calories from ultra-processed foods had a 31% higher chance of getting autoimmune hypothyroidism over 11 years.
- 3Kidney and cholesterol-related biomarkers explained about one-third of this link.
- 4Women on hormone therapy had an even higher risk.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
The American journal of clinical nutrition
Year
2025
Authors
Dong Liu, Yunnan Zhang, Z. Chen, Yan Hong, Tong Liu, Li-Hua Chen
Related Content
Claims (6)
Higher levels of apolipoprotein A and HDL cholesterol, which reflect cholesterol transport efficiency, are linked to part of the connection between consuming ultra-processed foods and developing autoimmune hypothyroidism, suggesting that disruptions in lipid metabolism are involved in the development of autoimmune thyroid disease.
Adults aged 40–69 who consume more than 20% of their daily calories from ultra-processed foods have a 31% higher rate of autoimmune-related hypothyroidism over 11.2 years compared to those who consume less, even after accounting for other lifestyle and dietary factors.
People who eat more ultra-processed foods have a higher rate of autoimmune-related hypothyroidism compared to those who eat less, and this pattern is seen in both men and women.
Higher intake of ultra-processed foods is linked to autoimmune hypothyroidism, and this link is partly explained by reduced kidney function, measured by elevated cystatin C levels, with a stronger effect in women than in men.
Women using hormone replacement therapy who consume more ultra-processed foods have a 6% higher relative risk of developing autoimmune-related hypothyroidism for each additional unit of ultra-processed food intake compared to women not using hormone replacement therapy.
In people with autoimmune thyroid conditions, eating certain foods causes measurable negative changes in bodily functions.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.