Impact of low iodine diets on ablation success in differentiated thyroid cancer: A mixed-methods systematic review and meta-analysis

source extracted confidence: high 2026-04-09
#humans #iodine #iodine-radioisotopes #thyroid-neoplasms #diet

Impact of low iodine diets on ablation success in differentiated thyroid cancer: A mixed-methods systematic review and meta-analysis

Herbert et al., 2022 | Clin Endocrinol (Oxf) | Meta Analysis

Citation

Herbert Georgia, England Clare, ... Atkinson Charlotte. Impact of low iodine diets on ablation success in differentiated thyroid cancer: A mixed-methods systematic review and meta-analysis. Clin Endocrinol (Oxf). 2022-Dec;97(6):702-729. doi:10.1111/cen.14751

Abstract

BACKGROUND: Debate remains regarding whether to recommend a low iodine diet (LID) before radioactive-iodine treatment and its duration and stringency. This mixed-methods review aimed to determine if iodine status affects treatment success, the most effective diet to reduce iodine status, and how LID impacts wellbeing. METHODS: Five electronic databases were searched until February 2021. An effectiveness synthesis (quantitative studies) and views synthesis (qualitative, survey, and experience-based evidence) were conducted individually and then integrated. Quality assessment was undertaken. RESULTS: Fifty-six quantitative and three qualitative studies were identified. There was greater ablation success for those with an iodine status of <50 mcg/L (or mcg/gCr) compared with ≥250 (odds ratio [OR] = 2.63, 95% confidence interval [CI], 1.18-5.86, n = 283, GRADE certainty of evidence very low). One study compared <50 mcg/L (or mcg/gCr) to 100-199 and showed similar rates of ablation success (OR = 1.59, 95% CI, 0.48-6.15, n = 113; moderate risk of bias). People following a stricter LID before ablation had similar rates of success to a less-strict diet (OR = 0.67, 95% CI, 0.26-1.73, n = 256, GRADE certainty of evidence very low). A stricter LID reduced iodine status more than a less strict (SMD = -0.40, 95% CI, -0.56 to -0.24, n = 816), and reduction was seen after 1 and 2 weeks. The main challenges were a negative impact on psychological health, over restriction, confusion, and difficulty for sub-groups. CONCLUSIONS: Although a LID of 1-2 weeks reduces iodine status, it remains unclear whether iodine status affects treatment success as only a few low-quality studies have examined this. LIDs are challenging for patients. Higher-quality studies are needed to confirm whether a LID is necessary.

Key Findings

Fifty-six quantitative and three qualitative studies were identified. There was greater ablation success for those with an iodine status of <50 mcg/L (or mcg/gCr) compared with ≥250 (odds ratio [OR] = 2.63, 95% confidence interval [CI], 1.18-5.86, n = 283, GRADE certainty of evidence very low). One study compared <50 mcg/L (or mcg/gCr) to 100-199 and showed similar rates of ablation success (OR = 1.59, 95% CI, 0.48-6.15, n = 113; moderate risk of bias). People following a stricter LID befo

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size 283
Age Range See abstract
Condition See abstract

MeSH Terms

  • Humans
  • Iodine
  • Iodine Radioisotopes
  • Thyroid Neoplasms
  • Diet
  • Treatment Outcome

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Meta-Analysis, Systematic Review, Journal Article, Research Support, Non-U.S. Gov't
  • Vertical: iodine

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09