Brown Seaweeds Effect on Glucose Tolerance and Appetite Response

Effect of Brown Seaweeds on Glycaemia, Gastric Emptying, and Appetite: A Randomized, Controlled Crossover Meal Study

The project is a randomized, 3-way, blinded crossover trial in which 20 healthy, fasted participants consume meals with 30 g of a linear corn starch and 5 g of one of the seaweeds, Laminara digitata or Undaria pinnatifida or a pea protein control. The primary aim is to investigate whether the brown seaweeds affect the postprandial glucose Area Under the Curve (AUC). Stomach emptying, insulin, C-peptide, appetite-regulating hormones (oxyntomodulin, glucagon, GLP-1 and PYY), and specific metabolites from the seaweeds in the urine and plasma as well as subjective satiety are also analyzed.

Study Overview

• Status: Completed
• Conditions: High Blood Glucose
• Intervention / Treatment: Other: LD; Other: UP; Other: CTR

Detailed Description

Brown seaweeds may contain bioactive compounds as they contain secondary plant metabolites, including flavonoids and other phenolic compounds as well as carotenoids. Dietary fibre is the major component of brown seaweeds, mainly composed from laminarans, alginates, fucans and cellulose. Several dietary fibers and secondary plant metabolites have been shown to have an impact on health and more specifically on glycemic control. Therefore, the aim of this study was to investigate whether two selected brown seaweeds have an effect on the postprandial glucose response to a starch load as well as several secondary measures, including appetite responses.

In a controlled crossover trial, 20 healthy fasted participants consumed 5 g of either Laminaria digitata (LD) or Undaria pinnatifida (UP) or 1 g of pea protein (CTR). The volunteers concomitantly ingested 200 mL of a drink with corn starch. Blood samples were drawn at baseline, as well as 20, 40, 60, 90, 120 and 180 min after the meal. Differences in glucose, insulin, C-peptide, plasma incretin concentrations, and insulin sensitivity index (ISI) were analyzed and appetite was scored by a visual analogue scale and a subsequent ad libitum test meal.

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Denmark
  • Frederiksberg, Denmark, 1958
    • Department of Nutrition, Exercise and Sports, University of Copenhagen

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 50 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

BMI 20-25 kg/m2. Waist circumference < 102 cm. Non-smoking. Like (can tolerate) seaweed, pasta, meat sauce as these foods are part of the test meal.

Can tolerate paracetamol (Pinex, Actavis, Denmark).

Exclusion Criteria:

Systemic infections, psychiatric or metabolic diseases, and any clinical condition, chronic or frequent use of medication (including blood thinners, excluding contraceptives), smoking (throughout the trial and 12 months before the start of the experiment), blood donations during or in the month leading up to the study period, elite athletes (> 10 hours of hard exercise / week, self-reported), high intake of alcohol (defined as a weekly intake of > 7 units for women and > 14 units for men), have or have had a drug addiction, participation in other scientific studies during the study period, lactating, pregnancy or ongoing planning of pregnancy, and vegetarianism or veganism.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

6

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Sequence A; The meal study was performed with Laminaria digitata (LD), Undaria pinnatifida (UP) or pea protein drink (CTR) in the sequence LD-UP-CTR	Other: LD; Participants ingested 5 g of Laminaria digitata followed by 30 g of corn starch mixed with 200 mL of water.; Other: UP; Participants ingested 5 g of Undaria pinnatifida followed by 30 g of corn starch mixed with 200 mL of water.; Other: CTR; Participants ingested 30 g of corn starch and 1 g of pea protein powder mixed with 200 mL of water.
Experimental: Sequence B; The meal study was performed with Laminaria digitata (LD), Undaria pinnatifida (UP) or pea protein drink (CTR) in the sequence LD-CTR-UP	Other: LD; Participants ingested 5 g of Laminaria digitata followed by 30 g of corn starch mixed with 200 mL of water.; Other: UP; Participants ingested 5 g of Undaria pinnatifida followed by 30 g of corn starch mixed with 200 mL of water.; Other: CTR; Participants ingested 30 g of corn starch and 1 g of pea protein powder mixed with 200 mL of water.
Experimental: Sequence C; The meal study was performed with Laminaria digitata (LD), Undaria pinnatifida (UP) or pea protein drink (CTR) in the sequence UP-LD-CTR	Other: LD; Participants ingested 5 g of Laminaria digitata followed by 30 g of corn starch mixed with 200 mL of water.; Other: UP; Participants ingested 5 g of Undaria pinnatifida followed by 30 g of corn starch mixed with 200 mL of water.; Other: CTR; Participants ingested 30 g of corn starch and 1 g of pea protein powder mixed with 200 mL of water.
Experimental: Sequence D; The meal study was performed with Laminaria digitata (LD), Undaria pinnatifida (UP) or pea protein drink (CTR) in the sequence UP-CTR-LD	Other: LD; Participants ingested 5 g of Laminaria digitata followed by 30 g of corn starch mixed with 200 mL of water.; Other: UP; Participants ingested 5 g of Undaria pinnatifida followed by 30 g of corn starch mixed with 200 mL of water.; Other: CTR; Participants ingested 30 g of corn starch and 1 g of pea protein powder mixed with 200 mL of water.
Experimental: Sequence E; The meal study was performed with Laminaria digitata (LD), Undaria pinnatifida (UP) or pea protein drink (CTR) in the sequence CTR-LD-UP	Other: LD; Participants ingested 5 g of Laminaria digitata followed by 30 g of corn starch mixed with 200 mL of water.; Other: UP; Participants ingested 5 g of Undaria pinnatifida followed by 30 g of corn starch mixed with 200 mL of water.; Other: CTR; Participants ingested 30 g of corn starch and 1 g of pea protein powder mixed with 200 mL of water.
Experimental: Sequence F; The meal study was performed with Laminaria digitata (LD), Undaria pinnatifida (UP) or pea protein drink (CTR) in the sequence CTR-UP-LD	Other: LD; Participants ingested 5 g of Laminaria digitata followed by 30 g of corn starch mixed with 200 mL of water.; Other: UP; Participants ingested 5 g of Undaria pinnatifida followed by 30 g of corn starch mixed with 200 mL of water.; Other: CTR; Participants ingested 30 g of corn starch and 1 g of pea protein powder mixed with 200 mL of water.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Plasma glucose Area Under the Curve (Glucose AUC)	The area under the plasma glucose concentration curve was calculated from 0-180 min after 30 g of corn starch was ingested.	0- 180 min

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Plasma glucose concentrations	Changes in the glucose concentrations determined by a mixed model analysis and subsequently at each time point with time 0 as a co-variate.	20, 40, 60, 90, 120 and 180 min
Serum Insulin Area Under the Curve	Area Under the Curve (AUC) for serum insulin.	0-180 min
Serum Insulin concentrations	Changes in the insulin concentrations determined by a mixed model analysis and subsequently at each time point with time 0 as a co-variate.	: 20, 40, 60, 90, 120 and 180 min
ISI (0-180)	Matsuda's Insulin Sensitivity Index	0-180 min
Serum C-peptide Area Under the Curve	Area Under the Curve (AUC) for serum C-peptide.	0-180 min
Serum C-peptide concentrations	Changes in the C-peptide concentrations determined by a mixed model analysis and subsequently at each time point with time 0 as a co-variate.	20, 40, 60, 90, 120 and 180 min
Plasma GLP-1 Area Under the Curve	Area Under the Curve (AUC) for plasma GLP-1.	0-180 min
Plasma GLP-1 concentrations	Changes in the plasma GLP-1 concentrations determined by a mixed model analysis and subsequently at each time point with time 0 as a co-variate	20, 40, 60, 90, 120 and 180 min
Subjective appetite scores assessed by visual analogue scale (VAS)	Area Under the Curve (AUC) for all VAS outcomes (satiety, hunger, fullness, prospective food consumption and comfort)	0-180 min
Subjective appetite scores assessed by visual analogue scale (VAS)	Changes in VAS outcomes (satiety, hunger, fullness, prospective food consumption and comfort), determined by a mixed model analysis and subsequently at each time point with time 0 as a co-variate	20, 40, 50, 70, 100, 130 and 180 min

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Metabolic profile in urine	Untargeted metabolic profile of urine samples measured in all samples collected before the meal and postprandially from 0-90 min, 90-180 min as well as in samples collected up to 24 hours later. The totality of the profiles is used to explore for changes after baseline as detected by multivariate statistics (PLS-DA) after dividing the data into a training and test set. Contrasts between each of the treatment groups and the placebo group will be assessed using the receiver-operator characteristics (ROC curves) comparing the training and test set.	0-24 hrs
Metabolic profile in plasma	Untargeted metabolic profile of plasma measured in all samples collected before the meal and postprandially from 0-180 min. The totality of the profile is used to explore for changes after baseline as detected by multivariate statistics (PLS-DA) after dividing the data into a training and test set. Contrasts between each of the treatment groups and the placebo group will be assessed using the receiver-operator characteristics (ROC curves) comparing the training and test set.	0-180 min

Collaborators and Investigators

• Sponsor: University of Copenhagen
• Collaborators: Ministry of Education, Malaysia; Universiti Malaysia Pahang

Publications and helpful links

General Publications

• Zaharudin N, Tullin M, Pekmez CT, Sloth JJ, Rasmussen RR, Dragsted LO. Effects of brown seaweeds on postprandial glucose, insulin and appetite in humans - A randomized, 3-way, blinded, cross-over meal study. Clin Nutr. 2021 Mar;40(3):830-838. doi: 10.1016/j.clnu.2020.08.027. Epub 2020 Aug 31.

Study record dates

Study Major Dates

• Study Start: May 1, 2015
• Primary Completion (Actual): July 1, 2015
• Study Completion (Actual): August 1, 2015

Study Registration Dates

• First Submitted: November 14, 2015
• First Submitted That Met QC Criteria: November 16, 2015
• First Posted (Estimate): November 18, 2015

Study Record Updates

• Last Update Posted (Actual): August 27, 2018
• Last Update Submitted That Met QC Criteria: August 23, 2018
• Last Verified: August 1, 2018

More Information

Terms related to this study

• Keywords: Insulin; Metabolomics; Glucose tolerance; C-peptide; Seaweed; Appetide
• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Hyperglycemia
• Other Study ID Numbers: M221