High iodine dietary intake is associated with type 2 diabetes among women of the E3N-EPIC cohort study

[helvella]

There has always been quite a lot of interest in and controversy about the idea of taking iodine in thyroid disorders.

The opinions range from actively avoiding foods known to be among even the slightly higher range of iodine content (e.g. some fish and shellfish), through simply eating without making any adjustment, to actively consuming very large doses of iodine as a supplement.

This paper sets the high intake range at 190.6-596.8 μg/day. This is far less than many active iodine supplementers take with anything from 5 to 30 milligrams being reported. (Possibly eight to fifty or more times the high range - depending how you calculate it.)

Even at this level, they report an association with type 2 diabetes.

Does something completely different happen with very high doses of iodine?

Clin Nutr. 2018 Aug 25. pii: S0261-5614(18)32386-0. doi: 10.1016/j.clnu.2018.08.015. [Epub ahead of print]

High iodine dietary intake is associated with type 2 diabetes among women of the E3N-EPIC cohort study.

Mancini FR1, Rajaobelina K1, Dow C1, Habbal T1, Affret A1, Balkau B2, Bonnet F3, Boutron-Ruault MC1, Fagherazzi G4.

Author information

1 CESP, INSERM U1018, Univ. Paris-Sud, UVSQ, Université Paris-Saclay, Villejuif Cedex, F-94805, France; Gustave Roussy, Villejuif, F-94805, France.

2 CESP, INSERM U1018, Univ. Paris-Sud, UVSQ, Université Paris-Saclay, Villejuif Cedex, F-94805, France; University Versailles, Saint Quentin, University Paris-Sud, Villejuif, France.

3 CESP, INSERM U1018, Univ. Paris-Sud, UVSQ, Université Paris-Saclay, Villejuif Cedex, F-94805, France; CHU Rennes, Université de Rennes 1, France.

4 CESP, INSERM U1018, Univ. Paris-Sud, UVSQ, Université Paris-Saclay, Villejuif Cedex, F-94805, France; Gustave Roussy, Villejuif, F-94805, France. Electronic address: [e-mail].

Abstract

BACKGROUND:

Iodine is an essential micronutrient needed for the production of thyroid hormones. Consequently, iodine insufficient and excessive intakes are associated with thyroid disorders. Despite the increase in diabetes prevalence worldwide and the close relationship between thyroid function and the risk of diabetes, the relationship between iodine intake and diabetes has been overlooked. The objective of the present study is to investigate the link between iodine intake and the risk of type 2 diabetes.

METHODS:

Cox proportional hazards regression models adjusted on potential confounders were used to calculate the hazard ratios and 95% confidence intervals for the associations between dietary iodine intake and type 2 diabetes risk among 71,264 women of the E3N-EPIC cohort.

RESULTS:

The average iodine intake in the study population was 155.6 μg/day (±47.1 μg/day). After adjusting for the main risk factors for diabetes, for hypo/hyperthyroidism, as well as for phosphorus intakes and consumption of dairy products and seafood, the hazard ratios (95% CI) for type 2 diabetes of women in the 4th (160.7-190.5 μg/day) and 5th (190.6-596.8 μg/day) quintiles groups of iodine intake were 1.27 (1.10-1.47) and 1.28 (1.07-1.53), respectively, compared to women with iodine intake below the 1st quintile (29.3-116.9 μg/day).

CONCLUSION:

This is the first study to investigate the relationship between dietary iodine intake and the risk of developing type 2 diabetes. More studies are warranted to further investigate the health effects of chronic high iodine intake, and in particular to investigate the biological mechanisms that underlie the association between iodine intake and type 2 diabetes.

Copyright © 2018 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

KEYWORDS:

Cohort study; E3N-Epic; Iodine; Type 2 diabetes

PMID: 30193875

DOI: 10.1016/j.clnu.2018.08.015

ncbi.nlm.nih.gov/pubmed/301...

European Prospective Investigation into Cancer and Nutrition

The European Prospective Investigation into Cancer and Nutrition (EPIC) study is a Europe-wide prospective cohort study of the relationships between diet and cancer, as well as other chronic diseases, such as cardiovascular disease. With over half a million participants, it is the largest study of diet and disease to be undertaken.[1]

EPIC is coordinated by the International Agency for Research on Cancer (IARC), part of the World Health Organization, and funded by the "Europe Against Cancer" programme of the European Commission as well as multiple nation-specific grants and charities.

en.wikipedia.org/wiki/Europ...

[LouiseRoberts]

Thanks for posting. : )