Cardiometabolic Properties of Omega-3 Functionalized With Hydroxytyrosol

The product to be tested is a combination of two key components: an oily preparation containing 97% eicosapentaenoic acid (EPA) and a natural extract (Oleacore®) with a high hydroxytyrosol content (10%). Oleacore® is naturally derived from olives using exclusively physical and mechanical methods and is commercialized by Olivenova Health SL (https://olivenova.com/es/). The EPA-97% component is supplied by Beeps Holding GMBH (https://bepsholding.com/el-holding/?lang=es). Three types of nutraceutical formulations will be prepared, and study participants will consume three capsules daily to achieve the following dosages:

• 2 g of EPA + 15 mg of hydroxytyrosol (HT) (3 Type-1 capsules, EPA+HT),
• 2 g of EPA (3 Type-2 capsules, EPA), and
• 2 g of seed oil (sunflower) as a placebo (3 Type-3 capsules, Placebo).

The daily dose of 15 mg HT was selected based on the EFSA claim for the prevention of LDL oxidation , while the 2 g EPA dose was established following EFSA recommendations for triglyceride reduction.

A chronic, randomized, controlled, crossover, double-blind, free-living study design is proposed, spanning 46 weeks. Following a two-week washout period, during which the consumption of extra virgin olive oil, and olives will be restricted, participants will be grouped based on baseline characteristics (control or hypertriglyceridemia). They will then be randomized into three groups (randomization performed using SPSS software), such that one-third of participants will receive EPA+HT, another third will receive EPA without HT, and the remaining third will receive a placebo nutraceutical containing sunflower oil with no EPA or HT.

Each intervention phase will last 12 weeks. After completing one intervention, participants will undergo a four-week washout period before transitioning to the next intervention. Before the start of each phase, participants will be provided with all necessary capsules (EPA+HT, EPA, or placebo) along with detailed consumption guidelines.Volunteers will take the capsules with lunch and dinner.

Additionally, during the study, volunteers will consume a commercial olive oil with a minimal phenol content as their culinary oil. This olive oil will also be supplied by the research team for family use (1 L/2 weeks). Participants will be instructed to maintain their usual lifestyle throughout the study but will be restricted from consuming any other culinary oils apart from the one provided by the research group, as well as olives. Furthermore, the use of dietary supplements containing antioxidants, other than vitamins, will be prohibited.

Participants will attend the Human Nutrition Unit (UNH) at ICTAN-CSIC on six occasions, corresponding to the beginning and end of each intervention phase. Once eligibility has been confirmed based on the inclusion and exclusion criteria, participants will attend the UNH for signing the informed consent, receiving olive oil for household consumption, and receiving instructions to begin the study.

During visits V1-V6 (corresponding to the start and end of each intervention with the different nutraceuticals), participants will report to the UNH at ICTAN-CSIC. Upon arrival, they will provide a fasting urine sample from their first morning void and a stool sample collected within the previous 24 hours. Additionally, a trained nurse will collect a fasting blood sample (40 mL, distributed into tubes containing various anticoagulants).

Blood pressure and heart rate will also be measured. Furthermore, participants will undergo a comprehensive anthropometric and body composition assessment. Dietary habits and physical activity levels will be monitored and evaluated during these visits.

Compliance with the intervention will be monitored through monthly telephone follow-ups, the collection of unused capsules, and the measurement of specific biomarkers, including plasma phosphatidylcholine-EPA levels as a marker of omega-3 fatty acid intake and urinary HT metabolites.

Inclusion criteria

• Age: 18 to 70 years old
• Hypertriglyceridemia (150-250 mg/dl) or normal levels of triglycerides levels (<150 mg/dl)

Exclusion criteria

• Presence of chronic illnesses
• Currently undergoing pharmacological treatment
• Smoking
• Pregnancy
• Adherence to a vegetarian or vegan diet