Seaweed Iodine Delivered Via Food or Supplementation (INNOVATE)

Iodine From Seaweed - a Randomised Controlled Trial of Food Versus Supplementation in Women With Marginal Habitual Iodine Intake

In this project, the investigators propose an intervention design testing the efficacy of a food reformulated with seaweed as an ingredient in meal, capsules against placebo and no intervention controls. The randomised control trial (supplementation) will last 24 weeks. The aim is to study the effect of the food matrix on variables associated with iodine nutrition: iodine status and thyroid function.

Study Overview

• Status: Completed
• Conditions: Iodine Deficiency
• Intervention / Treatment: Dietary supplement: Reformulated pizza; Dietary supplement: Control pizza; Dietary supplement: Seaweed capsule; Dietary supplement: Control capsule

Detailed Description

This study is a randomized, double-blind, placebo-controlled trial conducted in Glasgow, United Kingdom. Inclusion criteria are as follows: healthy premenopausal women aged 18 - 60 years who would remain a resident in Glasgow for 24 weeks; who were self-reported low iodine consumers consuming milk less than once per day and non-oily fish less than once per week. Those with a history of thyroid dysfunction, taking medications other than the contraceptive pill or smoking, as well as pregnant or lactating women and those planning to conceive, were excluded. Those taking dietary supplements containing iodine would also excluded and there was no restriction related to body mass index (BMI).

Participants are recruited via social media and advertisements displayed around the Greater Glasgow area. Interested parties are screened and, if eligible, invited to a 30-minute appointment at which participants were randomly assigned through a web-based randomisation service to one of four groups after consent is obtained; reformulated pizza, control pizza, iodine capsules, or placebo capsules. During this initial meeting anthropometric measurements, blood pressure and a venous blood sample are collected, and participants are also asked to complete a sociodemographic questionnaire and an iodine specific food frequency questionnaire (FFQ). Participants are provided with instructions and equipment to record a 3-day estimated food diary and to collect 12 spot urine samples at different times of day over 2-7 days. Upon returning the spot urine samples, participants were given either the pizzas or supplements to begin the intervention. Participants are asked to consume one pizza or supplement three times a week for 24 weeks. Participants are asked to collect a further 10-12 sample spot urine samples at week 2 of the intervention. Participants are asked to attend another 30-minute appointment at 12 and 24 weeks in which baseline measurements are repeated along with a change to diet questionnaire.

• Study Type: Interventional
• Enrollment (Actual): 96
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Glasgow, United Kingdom, G31 2ER
    • University of Glasgow

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 60 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

• self-reported healthy women
• aged 18 to 60
• pre-menopausal
• with no history of thyroid dysfunction
• without any known allergic reactions to foods
• not on medication that impact on absorption of nutrients from the gut
• not currently taking dietary / multivitamin supplements (must have discontinued usage 2 weeks prior the start of the study)

Exclusion Criteria:

• pregnancy
• lactation
• habitual consumption of seaweed-based products (>once per week), milk (>once per day), sea fish, non-oily, e.g. cod (>once per week)
• veganism (as food products contains cheese)
• Involvement in another research study where diet is restricted, modified, or dietary habits are studied.
• women who have reached menopause.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Reformulated pizza; Participants must consume a nutritionally balanced pizza reformulated with seaweed (Ascophyllum nodosum) as an ingredient 3 times a week for 24 weeks	Dietary supplement: Reformulated pizza; Reformulated food with 400ug of iodine per meal, three times per week (to achieve 122% of weekly recommended intakes - average 140ug/day).
Placebo Comparator: Control pizza; Participants must consume a nutritionally balanced pizza without seaweed, 3 times a week for 24 weeks	Dietary supplement: Control pizza; Control (placebo) meal to consume thrice weekly (no iodine supplementation).
Experimental: Seaweed capsule; Participants must consume a capsule containing powdered Ascophyllum nodosum 3 times a week for 24 weeks	Dietary supplement: Seaweed capsule; Capsules containing seaweed extract, the iodine-rich ingredient in the reformulated pizza, 400ug iodine per capsule, to be consumed three times per week (122% of weekly recommended intake).
Placebo Comparator: Control capsule; Participants must consume an empty capsule 3 times a week for 24 weeks	Dietary supplement: Control capsule; Empty capsules (placebo)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in urinary iodine concentration (UIC)	Change in UIC assessed in pooled spot urine samples at 12 weeks, from baseline	0, 12 weeks
Change in urinary iodine concentration (UIC)	Change in UIC assessed in pooled spot urine samples at 24 weeks, from baseline	0, 24 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in body weight	Changes in body weight assessed from baseline at 12 and 24 weeks	0, 12, 24 weeks
Changes in body mass index	Changes in body mass index assessed from baseline at 12 and 24 weeks	0, 12, 24 weeks
Changes in waist circumference	Changes in waist circumference assessed from baseline at 12 and 24 weeks	0, 12, 24 weeks
Concentration of thyroid stimulating hormone	measured by immunoassay	0, 12, 24 weeks
Concentration of thyroglobulin	measured by immunoassay	0, 12, 24 weeks
Concentration of Free Triiodothyronine	measured by immunoassay	0, 12, 24 weeks
Concentration of Thyroxine	measured by immunoassay	0, 12, 24 weeks
Dietary iodine intake	estimated by food frequency questionnaire (FFQ)	0, 12, 24 weeks
Change in urinary iodine concentration (UIC)	Change in UIC assessed in pooled spot urine samples at 2 weeks, from baseline	0, 2 weeks

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
concentration of triglycerides	measured in blood	0, 12, 24 weeks
concentration of total cholesterol	measured in blood	0, 12, 24 weeks
concentration of HDL/LDL cholesterol	measured in blood	0, 12, 24 weeks
glucose concentration	measured in blood	0, 12, 24 weeks

Collaborators and Investigators

• Sponsor: University of Glasgow
• Investigators: Principal Investigator: Emilie Combet, University of Glasgow

Study record dates

Study Major Dates

• Study Start (Actual): February 12, 2018
• Primary Completion (Actual): September 5, 2019
• Study Completion (Actual): September 5, 2019

Study Registration Dates

• First Submitted: April 27, 2021
• First Submitted That Met QC Criteria: April 29, 2021
• First Posted (Actual): May 6, 2021

Study Record Updates

• Last Update Posted (Estimate): January 9, 2023
• Last Update Submitted That Met QC Criteria: January 6, 2023
• Last Verified: January 1, 2023

More Information

Terms related to this study

• Keywords: supplementation; iodine; thyroid function; seaweed; reformulation; food matrix
• Other Study ID Numbers: 133109

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No