This randomized, single-blind, crossover clinical trial aims to evaluate Echium oil and Ahiflower® oil as sustainable, plant-based alternatives to marine oils for omega-3 supplementation. Although fish oil is the primary dietary source of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), its use as a dietary supplementation presents several drawbacks, including high cost, potential contamination, limited global supply, and sustainability concerns. Echium and Ahiflower oils are naturally rich in stearidonic acid (SDA), a metabolic intermediate that bypasses the rate-limiting Δ6-desaturase step in the omega-3 pathway, potentially enhancing the conversion to EPA.

Fifteen participants will undergo three 8-week intervention phases-Echium oil (15 g/day), Ahiflower oil (15 g/day), or EPA capsules (2.34 g/day)-separated by four-week washout periods. Blood samples will be collected before and after each phase to measure fatty acid profiles in plasma, plasma fractions, and erythrocytes using GC-MS. Anthropometric and biochemical parameters will also be assessed. The study seeks to determine whether SDA-rich plant oils can effectively increase EPA levels in humans and potentially reduce the reliance on marine oils for cardiovascular health benefits.

Inclusion Criteria:

• Inclusion criteria will include individuals of both sexes, aged 18 to 30 years, without contraindications for using fish oil or vegetable oil supplements. Women must not be pregnant or breastfeeding.

Exclusion Criteria:

• will include vegetarianism or veganism; the use of triglyceride-lowering medications or dietary supplements; consumption of fish oil or other n-3 or n-6 PUFA supplements/drugs within one month before the trial; consumption of fatty fish (salmon, herring, mackerel, albacore tuna, or sardines) more than twice a month in the month before the trial; and unwillingness to avoid PUFA supplements and seafood throughout the study period. Additional exclusions will include severe heart failure, active severe liver disease, planned coronary intervention or surgery, history of acute or chronic pancreatitis, known hypersensitivity to fish, shellfish, or capsule ingredients, and autoimmune diseases requiring immunosuppressive therapy or current systemic corticosteroid use. Other exclusion criteria will encompass active neoplasms requiring surgery, chemotherapy, or radiation within the past 12 months (patients who underwent curative surgery without further treatment in the last 12 months may be eligible); inflammatory bowel disease or chronic diarrhea; significant non-transient hematological abnormalities; renal dysfunction; severe liver disease; inability to provide informed consent; participation in another clinical trial involving an investigational agent within the past 90 days; malabsorption syndrome; recent drug or alcohol abuse; atrial fibrillation; or bleeding disorders. Adherence to the prescribed dosage will be assessed by tracking the residual oil sachets and capsules returned by participants. If fewer than 80% of the doses over the full study period are consumed, participants will be classified as non-compliant, and their data will be excluded from efficacy analyses.