Response to an Intervention With Omega-3 (RIO - Study) (RIO)

Response to an Intervention With Omega-3 Fatty Acids on Lipid and Inflammatory Profiles in Overweight and Obese Individuals With Hypertriglyceridemia in Valdivia, Chile (RIO - Study)

The RIO-Study project is a randomized, controlled, double-blind, crossover trial aimed at determining the effectiveness of omega-3 fatty acids at nutritional doses on lipid metabolism and inflammation in overweight and obese individuals with hypertriglyceridemia in Chile.

Study Overview

• Status: Completed
• Conditions: Overweight; Hypertriglyceridemia
• Intervention / Treatment: Dietary supplement: Omega-3; Dietary supplement: HOSO

Detailed Description

The study will include 40 participants (each participant will serve as their own control) aged 18-65, with 25-34.9 kg/m2 BMI and fasting triglycerides (TG) of 100-215 mg/dL. The intervention consists of 250 mg EPA from algae oil versus high oleic sunflower oil (HOSO) for 6 weeks each, after a 10-week washout period, the treatments will be switched for another 6 weeks, considering four visits during the whole study. The main outcomes to be evaluated are serum triglyceride levels, expression of target genes in peripheral blood mononuclear cells (PBMCs), low-grade inflammation biomarkers, and very low-density lipoprotein (VLDL) atherogenic properties. The study also analyzes background diet, chrononutrition, and physical activity aspects. Results are expected to provide new insights into the effects of nutritional doses of omega-3 in the Chilean population, particularly on fasting and postprandial triglyceride metabolism and cardiovascular disease risk reduction.

Before and after each intervention period, fasting blood samples will be collected. On each visit day, participants will consume a standardized breakfast (three slices of white bread with butter and jam), and postprandial blood samples will be taken at 0, 2, 4, and 6 hours to measure triglycerides and other lipid parameters.

The study will assess:

1. Serum triglyceride levels in fasting and postprandial states
2. Expression of target genes Peroxisome proliferator-activated receptor alpha (PPARα) and Sterol regulatory element binding protein-1 (SREBP1c) in peripheral blood mononuclear cells (PBMCs) at fasting (0h) and postprandial (4h) states
3. Levels of low-grade inflammation biomarkers Tumor Necrosis Factor-Alpha (TNFα) and Interleukin 6 ( IL-6) at fasting (0h) and postprandial (4h) states
4. Very low-density lipoprotein (VLDL) atherogenic properties in the fasting state Additionally, the investigators will collect data on chrononutrition, physical activity, and energy drink intake to understand their impact on lipid metabolism. Anthropometric measurements and bioimpedance analysis will be performed at each visit.

The study will collaborate with international partners for specialized analyses, including gene expression studies and VLDL atherogenic properties assessment.

This comprehensive approach aims to provide new insights into the effects of nutritional doses of omega-3 fatty acids on lipid metabolism and inflammation in the Chilean population, with a particular focus on postprandial triglyceride metabolism and cardiovascular disease risk reduction.

• Study Type: Interventional
• Enrollment (Actual): 40
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Chile
  • Los Ríos Region
    • Valdivia, Los Ríos Region, Chile, 5090000
      • Universidad San Sebastián

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Adults between 18 and 65 years old, male and female.
• Body mass index (BMI) between 25 - 34,9 kg/m2.
• Fasting triglycerides between 100-215 mg/dL (1.13-2.43 mmol/L).

Exclusion Criteria:

• Unable to give informed consent.
• If you consume Omega-3 (you must stop consumption at least 10 weeks prior).
• Normal or Obesity Nutritional Status. Large weight variation (>10%) in the last 3 months.
• Triglycerides > 215 mg/dL.
• Blood pressure > 140/90 mmHg.
• Uncontrolled metabolic and chronic diseases (reference parameters for the disease in question will be considered).
• Pregnant women or those who are breastfeeding.
• Allergy or intolerance to gluten, milk protein and/or lactose, or any ingredient in the capsules (omega-3, oleic acid oil).
• Use of medications that affect lipid metabolism: Fibrates. (Statins will be allowed only if the treatment has been ongoing for over 3 months).
• Blood donation two months before or during the study period.
• Excessive alcohol consumption (>3 cans of beer per day)
• Taking anticoagulants.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Marine Omega-3 fatty acid supplement; Participants will be randomized to either star to receive a capsule/day with omega-3 fatty acid from 1g Nannochloropsis sp. microalga (250 mg of EPA) for 6 weeks. Followed by a wash-out period of 10 weeks.	Dietary supplement: Omega-3; Dietary Supplement: Omega-3 In the marine Omega-3 fatty acid period, the participants will receive a capsule with 250 mg of EPA per day during 6 weeks.
Placebo Comparator: High-oleic sunflower oil (HOSO) containing no EPA or other omega-3 fatty acid; Participants will be randomized to either star to receive a placebo capsule/day with the same weight of high oleic sunflower oil -HOSO (with no EPA or other omega-3 fatty acid content), for 6 weeks. Followed by a wash-out period of 10 weeks.	Dietary supplement: HOSO; Dietary Supplement: HOSO In the HOSO period, the participants will receive a capsule with the similar weight of HOSO per day during 6 weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fasting TG (mg/dL)	Baseline serum levels of circulating triglycerides	up to 6 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postprandial TG (mg/dL)	Triglyceride concentration (mg/dL) measured by enzymatic colorimetric assay at baseline (fasting) and at 2, 4, and 6 hours after consumption of a standardized 50 g fat meal.	up to 6 weeks
Change in mRNA expression levels of lipid metabolism genes in Peripheral Blood Mononuclear Cells (PBMCs)	Fold change in mRNA expression of genes of lipid metabolism in PBMCs at 0h and 4h, measured by RT-qPCR	up to 6 weeks
Change in concentrations (pg/mL) of pro-inflammatory cytokines TNF-α and IL-6	Serum concentrations (pg/mL) of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) measured by enzyme-linked immunosorbent assay (ELISA) at fasting (0h) and 4 hours postprandial following a standardized test meal	up to 6 weeks
Fasting plasma glucose concentration (mg/dL)	Fasting levels before and after intake of omega-3 or HOSO	up to 6 weeks
Fasting serum Low-Density Lipoproteins, High-Density Lipoproteins, Very Low-Density Lipoproteins (mg/dL)	Fasting levels before and after intake of omega-3 or HOSO	up to 6 weeks

Collaborators and Investigators

• Sponsor: Universidad San Sebastián

Publications and helpful links

Helpful Links

• RIO-Study web site

Study record dates

Study Major Dates

• Study Start (Actual): July 30, 2024
• Primary Completion (Actual): June 30, 2025
• Study Completion (Actual): June 30, 2025

Study Registration Dates

• First Submitted: July 10, 2024
• First Submitted That Met QC Criteria: August 1, 2024
• First Posted (Actual): August 5, 2024

Study Record Updates

• Last Update Posted (Estimated): September 25, 2025
• Last Update Submitted That Met QC Criteria: September 21, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Keywords: Omega-3 fatty acids; Lipid profile; Postprandial TG response; Inflammatory profile
• Additional Relevant MeSH Terms: Nutrition Disorders; Metabolic Diseases; Overnutrition; Body Weight; Hyperlipidemias; Dyslipidemias; Lipid Metabolism Disorders; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Overweight; Hypertriglyceridemia; Fatty Acids; Lipids; Fatty Acids, Unsaturated; Oils; Dietary Fats; Fats; Fatty Acids, Omega-3; Dietary Fats, Unsaturated; Fish Oils; Docosahexaenoic Acids
• Other Study ID Numbers: CEC -USS N°42-24

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No