The earliest association between fish and human health was noted in 1944 when Sinclair observed that coronary artery disease was very rare among the Greenland Eskimos. The diet of the Eskimos consisted of a large amount of fat from fish, seals, and whales, which are rich sources of omega-3 fatty acids. Subsequent research revealed that consuming these fatty acids not only benefits cardiovascular health but also helps reduce cancer, aids in weight loss, alleviates rheumatoid arthritis, prevents osteoporosis, manages diabetes, and addresses various other harmful bodily disorders.
The relationship between Fish Oil and Omega-3:
Fatty acids in food are classified into two main groups: saturated fatty acids (where carbon atoms are connected by single bonds) and unsaturated fatty acids (where carbon atoms are connected by at least one double bond). Omega-3 fatty acids are a type of unsaturated fatty acid with the first double bond located at the third carbon atom. The most important omega-3 fatty acids are ALA (alpha-linolenic acid), EPA (eicosapentaenoic acid), and DHA (docosahexaenoic acid).
Fish oil is derived from the fat of fatty fish and is rich in omega-3 fatty acids, specifically EPA and DHA.
Effects of Fish Oil:
Research data to date have demonstrated several potential benefits of omega-3 fatty acids for cardiovascular and metabolic health. Specifically, EPA and DHA in fish oil omega-3s may help:
- Improve cardiovascular health: Studies have shown that omega-3s play a role in maintaining low blood cholesterol levels, reducing arrhythmias, and lowering blood pressure. Large clinical trials have demonstrated the benefits of omega-3 fatty acid supplementation in the secondary and primary prevention of coronary artery disease.
- Enhance inflammatory conditions: Omega-3s can improve conditions such as rheumatoid arthritis, systemic lupus erythematosus, Raynaud’s disease, and other autoimmune disorders.
- Improve depression and mental health symptoms: The brain contains a significant amount of fat, with 60% of the brain’s weight being fat. Omega-3 fatty acids are essential for maintaining proper brain function and can help alleviate symptoms of depression and other mental health conditions.
- Prevent and support cancer: Omega-3 fatty acids help maintain healthy breast tissue and may prevent breast cancer. Recent studies indicate that individuals who include fish oil in their diet have fewer carcinogenic substances in their colon compared to those who do not use fish oil.
Dosage:
Fish oil supplements on the market vary widely in purity and omega-3 fatty acid content (often expressed as EPA and DHA).
Research indicates that consuming fish at least once a week can reduce the risk of cardiovascular disease by 16%, and eating fish 2-4 times a week can further lower the risk of stroke by an additional 6% compared to eating fish less than once a week. Therefore, the American Heart Association recommends that adults eat fish, particularly fatty fish, at least twice a week. If adequate omega-3 intake from fish is not possible, fish oil supplements can be used. Fish oil is considered safe for most people at a supplemental dose of approximately 2-3 grams per day.
For individuals with coronary artery disease, the recommended fish oil dosage is approximately 1 gram (EPA + DHA) per day.
For individuals with elevated triglyceride levels, the recommended dosage is approximately 2-4 grams (EPA + DHA) per day to help reduce triglycerides by 20-40%.
Side effects:
In small clinical trials, fish oil doses up to 12 grams per day (containing 6 grams per day of omega-3 fatty acids) have been used for over two years without any serious adverse effects. However, the U.S. Food and Drug Administration (FDA) recommends not exceeding 3 grams per day of combined EPA and DHA (higher doses should only be used under clinical supervision).
The most common side effects of fish oil include a fishy aftertaste and digestive disturbances, especially at high doses, such as nausea, belching, vomiting, bloating, diarrhea, and constipation.
Omega-3 fatty acids have antithrombotic properties, so caution is needed when using fish oil in patients with bleeding disorders or those taking medications that affect blood clotting. The risk of bleeding is only associated with very high doses (>7 grams of omega-3 fatty acids per day).
Concerns about contamination from environmental pollutants, particularly mercury, are addressed by the fact that fish oil capsules are typically free of mercury. Mercury is water-soluble and binds to proteins, so it is present in the flesh of the fish rather than in the fish oil.
Specialist level 2 doctor. Nguyen Chi Thanh
References:
- Decision No. 5333/QĐ-BYT dated December 23, 2020, by the Ministry of Health on the issuance of specialized documentation “Primary Prevention of Cardiovascular Diseases.”
- Hồ Huỳnh Quang Trí (2010), “Omega-3 Fatty Acids and Cardiovascular Diseases,” Ho Chi Minh City Cardiology Journal, electronic edition published on April 26, 2010.
- Guo, ‘Chapter 5 – LIPIDS AND LIPID RELATED FUNCTIONAL FOODS’, in Functional Foods, M. Guo, Ed., in Woodhead Publishing Series in Food Science, Technology and Nutrition, Woodhead Publishing, 2009, pp. 161–196. doi: 10.1533/9781845696078.161.
- Fish oil: Physiologic effects and administration- UpToDate. Accessed: July 21, 2024.
- Micromedex – Monograph on Omega-3 Fatty Acids. Accessed on July 25, 2024.
- Usage information approved by the Ministry of Health for Omesoft fish oil capsules (180 mg EPA, 20 mg DHA). https://cdn.drugbank.vn/1557117313932_131(8).pdf
