Omega-3 fatty acids (Ω3) have been known to be good for the heart and brain. Among Ω3, EPA is especially good for the heart and blood vessels, and DHA is mainly good for the brain. EPA is involved in blood coagulation, constriction and relaxation of arteries, and reduces LDL cholesterol and triglycerides. It also has the effect of relieving inflammation. DHA is a main component of cell membranes and nerve cells. EPA and DHA cannot be synthesized in the body, so they must be consumed externally. EPA and DHA are contained in large quantities in green fish.
There is controversy over whether Ω3 supplementation has the effect of reducing cardiovascular disease (CVD) risk. In particular, research results on patients with a history of CVD or high-risk groups are inconsistent. In 2019, the U.S. Food and Drug Administration recognized the somewhat conflicting but “reliable evidence” that EPA+DHA intake reduces high blood pressure and coronary heart disease (CHD). In the same year, the American Heart Association (AHA) guidelines recommended EPA+DHA supplementation for patients with hypertriglyceridemia to prevent CVD. It is said that 2-4g per day can lower neutral fat by 20-40%. However, in 2023, six organizations, including the AHA, jointly announced new guidelines. “The use of supplements including fish oil, Ω3, and vitamins is not recommended for patients with chronic coronary artery disease.” It is difficult to accept the premise that Ω3 supplementation has cardioprotective effects.
What made the AHA guidelines different? This is because evidence suggests that Ω3 supplementation increases the risk of atrial fibrillation (AF). AF is the most common cardiac arrhythmia (2014 paper). The atrium is where the blood flows into the heart, and AF is a phenomenon in which the atrium beats abnormally fast. AF increases the risk of blood clots, stroke, heart failure, and heart attack. Looking at the results of recent large-scale, long-term randomized controlled trials (RCTs), intake of 4 g of EPA per day in high-risk patients (2020 paper) and intake of 1.8 g of Ω3 per day in patients with myocardial infarction (2021 paper, 2023 paper) reduce the risk of AF. reported to be significantly increased. Four meta-analyses published in 2021 found that Ω3 supplementation increased the risk of AF by 25% to 31%.
The latest research results do not mean that Ω3 itself is harmful to the heart. Research results showing a significant increase in AF risk are mostly related to high doses (2022 paper). In a meta-analysis that subdivided the dose, the increased risk of AF due to intake of less than 1g per day was as low as 12%. In people without a history of CVD, intake of 840 mg of EPA+DHA per day slightly increased the risk of AF (2021 RCT) or was not related to the occurrence of CVD (2018 RCT). Considering that EPA+DHA is effective in lowering blood pressure, heart rate, and reducing triglycerides (2018 meta-analysis), the risk of AF is negligible in healthy people. When healthy adults consume 566 mg of EPA+DHA per day, the risk of CHD death decreases by 37% (2008 meta-analysis). In particular, Ω3 in fish oil is effective in preventing ventricular arrhythmia, which is a relatively rare cause of sudden death (1997 paper).
It is best to consume Ω3 through natural foods rather than supplements. A healthy diet includes eating oily fish along with vegetables and fruits at least twice a week (AHA guidelines). Then we can consume the EPA+DHA we need (2008 paper).
Attorney Seungdeok Ko (Chairman of Korea Youth Shelter Council)
2023-10-20 23:25:00
#Omega #good #bad #heart
