Fish oil's support for heart health primarily comes from its rich content of Omega-3 fatty acids (mainly EPA and DHA), which work through multiple mechanisms. Here are the core benefits supported by scientific evidence:
1. Lowering Triglycerides: The most clearly defined and significant benefit. High doses of Omega-3 (especially EPA) can significantly lower blood triglyceride levels (by 15%-30%), a major risk factor for atherosclerosis.
2. Anti-inflammatory Effects: Chronic inflammation is a key driver of atherosclerosis. Omega-3 fatty acids are converted in the body into active substances with anti-inflammatory effects (reductin and protective agents), helping to reduce inflammation in the blood vessel walls.
3. Improving Blood Pressure: Moderate supplementation may have a mild auxiliary effect in lowering blood pressure, especially for people with hypertension.
4. Stabilizing Heart Rhythm and Reducing the Risk of Arrhythmias: Omega-3 helps stabilize the electrical activity of myocardial cells, potentially reducing the risk of certain types of arrhythmias (such as atrial fibrillation) and offering some protection against sudden cardiac death.
5. Antithrombotic Effect: Slightly reduces platelet aggregation and the tendency to form thrombi, but its effect is weaker than drugs like aspirin.
6. Improves Vascular Endothelial Function: Helps maintain vascular dilation and elasticity, which is crucial for maintaining healthy blood flow.
7. Slows the Progression of Atherosclerotic Plaques: Some studies suggest that high-purity fish oil may slow the progression of arterial plaques, but the effect is not absolute.
Important Evidence and Suitable Population:
Confirmed Cardiovascular Disease: Numerous studies have confirmed that high-dose prescription-grade fish oil (especially pure EPA formulations) can reduce the risk of cardiovascular events (such as myocardial infarction and stroke) in patients with coronary heart disease or myocardial infarction. Over-the-counter fish oil is also beneficial as an adjunct treatment.
High-Risk Groups (Hypertriglyceridemia): The American Heart Association recommends it as one of the treatment methods.
Prevention in Healthy Individuals: Beneficial through dietary intake, but evidence for the preventive effect of supplements is relatively weak.
How to Obtain Fish Oil/Omega-3?
Preferred Food Sources:
Fat Fish: Eat twice a week (approximately 150-200 grams per serving) of salmon, mackerel, sardines, herring, trout, etc.
Supplements (when dietary intake is insufficient):
Choose high-concentration, high-purity products: Focus on the total EPA+DHA content on the label, not the total weight of the fish oil. Choose products certified by third parties (such as IFOS, GOED) to ensure purity (free from heavy metals and contaminants).
Dosage: The usual maintenance dose is 500-1000 mg of EPA+DHA daily; higher doses may be needed to treat high triglycerides (under a doctor's guidance, such as 2000-4000 mg/day).
Note: Fish oil is different from cod liver oil, which is rich in vitamins A and D but low in Omega-3. Do not confuse them.
Precautions and Potential Risks:
Drug Interactions: Fish oil has a mild anticoagulant effect. Concomitant use with anticoagulants such as warfarin and aspirin may increase the risk of bleeding. Use under the guidance of a doctor.
Side effects: High doses may cause gastrointestinal upset, fishy odor, and belching. These can be relieved by choosing enteric-coated capsules or taking it with meals.
Purity is crucial: Inferior fish oil may contain contaminants (such as mercury and PCBs). Choose a reliable brand.
Summary recommendations:
For heart health, a balanced diet (including fish) is the cornerstone. If supplementation is needed:
Prevention/Health maintenance: Consider supplementing with 500-1000 mg of EPA + DHA daily.
Treatment of specific conditions (such as high triglycerides): Always consult a doctor. Prescription-grade high-dose products may be required, along with lifestyle changes and medication.
