Fish Oil Supplement Ineffective for Heart Health

Fish oil supplement was believed to be effective in the prevention of heart problems. Clinical trials suggested that fish oil could be useful in preventing heart attacks among heart patients. It was postulated that fish oil improves heart health by resolving inflammation in the blood vessels. Besides that, fish oil also mitigates heart problems by decreasing serum triglyceride levels. Both proposed mechanism of actions of fish oil reduces the risk of having narrowed blood vessels due to plaque or fatty build-up.

Fish oil contains essential omega-3 fatty acids that are obtained through diet. These fatty acids are docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Dietary sources rich in these fatty acids are oily fishes, such as salmon, mackerel and sardines. Nevertheless, the body can convert a plant-based omega-3 fatty acid, alpha-linolenic acid (ALA), to DHA and EPA. Good sources of ALA are flaxseeds, chia seeds, walnuts, pumpkin seeds and canola oil.

Although fish oil supplement was greatly publicised for improving heart health, some researches refuted the beneficial claims of fish oil. In 2013, a study revealed that the supplements were ineffective in reducing heart attacks, strokes, or deaths from heart diseases among high risk patients. Recently, the Cochrane researchers concluded that fish oil only provided little, if any benefit, on the outcomes that were studied.

What does Cochrane Review say?

The review included 79 trials that involved over 112,000 adult subjects from North America, Europe, Australia and Asia. The subjects were randomly assigned to increase their omega-3 fatty acids or to maintain their usual intake of fat for at least a year.

It was found that increasing DHA and EPA has minimal or no effect on reducing death related to heart problems, stroke, or heart irregularities. The risk of death from any cause only reduced by 0.2 % when compared between intervention and control group, with the risk at 8.8 % and 9.0 % respectively. Nevertheless, DHA and EPA slightly decreased serum triglycerides and increased high-density lipoprotein (the good cholesterol).

The systematic review also suggested that increased ALA consumption probably has little or no effect on heart-related deaths or deaths from any cause. However, ALA appeared to provide minimal risk reduction for heart irregularities from 3.3 % to 2.6 %.

Take away

The Cochrane researchers suggested that the chance of deriving any meaningful benefit from omega-3 supplements is one in a thousand. Despite that, eating oily fish is still recommended as part of a healthy diet for heart and general health.

Reference

1. Weitz D, Weintraub H, Fisher E, Schwartzbard AZ. Fish oil for the treatment of cardiovascular disease. Cardiol Rev. 2010 Sep-Oct; 18(5): 258–263. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3217043/
2. LeWine H. Fish oi: Friend or foe? [Internet] [cited 2018 July 21] Available from: https://www.health.harvard.edu/blog/fish-oil-friend-or-foe-201307126467
3. Abdelhamid AS, Brown TJ, Brainard JS, Biswas P, Thorpe GC, et al. Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease. Cochrane Database Syst Rev. 2018 July 18; 7. Available from: http://cochranelibrary-wiley.com/doi/10.1002/14651858.CD003177.pub3/full
4. New Cochrane health evidence challenges belief that omega 3 supplements reduce risk of heart disease, stroke or death. [Internet] [cited 2018 July 24] Available from: https://www.cochrane.org/news/new-cochrane-health-evidence-challenges-belief-omega-3-supplements-reduce-risk-heart-disease
5. Fish oil supplements for a healthy heart ‘nonsense’. [Internet] [cited 2018 July 24] Available from: https://www.bbc.co.uk/news/health-44845879

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Tags

• Fish oil
• Heart health
• Supplements