Fish oil is rich in omega-3 fatty acids (omega-3s) such as Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA), which are commonly known to benefit health and can be obtained by eating fish or consuming fish oil supplements.
Over the past few years, we have been hearing more and more about fish oil. It is aggressively advertised by several companies as a wonder supplement and its sales have increased significantly in the past decade. But how effective is fish oil? How much of the so-called fish oil facts are a reality and how much is a myth or propaganda?
In this article, we have tried to talk about how effective fish oil is known to be in several disease conditions on the basis current level of research. To well inform the readers on the other side of the story, a contrary perspective to this is also discussed in a separate article.
Overall research on fish oil benefits is inconclusive or insufficient
As per the scientific community, the overall research on the benefits of fish oil conducted across several decades, geographies, and patient types is considered inconclusive or insufficient. A single opinion is lacking among researchers, clinicians, and industry professionals, as it is largely based on individual research, clinical experience, personal beliefs, and commercial interests.
However, over the last decade, fish oil supplements are most commonly used for diseases of the heart and the blood system (cardiovascular diseases). It is also used in conditions of brain, eyes, bones, joints and muscles, lungs, immune system, cancer, and kidneys of varying degrees. Out of these, existing research suggests that fish oil is likely to be effective in certain disease conditions and may or may not benefit in several others.
The chart depicts how effective is fish oil in several diseases as per the amount and quality of available scientific evidence. It is based on the information developed by Natural Medicine Comprehensive Database, US.
However, fish oil is known to be effective in cardiovascular conditions
In the US, there is a broad level of consensus among key institutes, such as the National Institute of Health (NIH), American Heart Association (AHA), the Mayoclinic, and Harvard Medical School on the benefits of fish oil in most of the below-mentioned cardiovascular conditions, such as:
- Lowering very high triglyceride levels
- Preventing clot and plaque formation
- Slight reduction in blood pressure
- Decreasing risk of abnormal heartbeats (arrhythmias)
Experts at Harvard suggest going slow on fish and avoiding supplements in case of hard-to-control angina, severe heart failure, or an implanted cardioverter-defibrillator (ICD).
However, the United States Food and Drug Administration so far has approved two pharmaceutical grade prescription supplements (Lovaza and Vascepa) only for very high triglyceride levels in adults (>500mg/dl). As depicted, this is the only condition where current research is sufficiently known to prove that fish oil was effective.
The AHA, as well as the European Society of Cardiology, recommends fish and fish oil supplements for certain cardiovascular diseases.
The AHA recommends eating fatty fish at least two times a week with each serving of about 3.5 oz. of fish baked or grilled, using low-fat, low-sodium seasonings such as spices, herbs, and lemon juice. Omega-3s from fish oil are preferred to be consumed through foods rather than in supplemental form.
As per the guidelines from the European Society of Cardiology (ESC), two portions of fish per week with at least one being oily fish should be consumed, and about 1 gram of pharmaceutical grade supplement is to be taken by those who cannot eat fish. Experts in the ESC think that eating fish is better due to vitamin D, selenium, and iodine in it and absence of final evidence that suggest benefits are due to omega-3s in fish.
The scientific acceptance and popularity of benefits of fish oil is more across several European countries than in the US, particularly in the case of cardiovascular diseases. Prescribing fish oil supplements to a patient on second day of a heart attack is a common event in some European countries and missing this is considered nearly malpractice. Doctors in the US appear to be less aggressive in prescribing it for this reason.
Fish oil would not benefit in type 2 diabetes, however in several diseases, it may or may not prove to be effective in ongoing research
As evident from the chart, the existing level of research suggests that fish oil is most likely not effective in Type 2 diabetes.
Several medical associations and respective physicians in the US and Europe continue to recommend fish oil through fish or supplements for diseases of the brain, eyes, bones, joints and muscles, lungs, immune system, cancer, and kidneys. However, in line with the chart, it may or may not finally prove to be beneficial in certain diseases according to the ongoing research.
Out of many disease conditions that may be benefited from fish oil, rheumatoid arthritis, and protection from cyclosporine drug toxicity look like two conditions with highest chances. On the other hand, chest pain due to angina is one such cardiovascular condition wherein fish oil may not prove to be beneficial.
It is widely accepted among researchers and clinicians that continued research will lead to a better consensus on how fish oil is effective in several disease conditions. Till then, the weight of scientific evidence is further towards cardiovascular disease.
There has been less than the required research in many other diseases to know if fish oil could be effective or not.
There is limited research in certain brain and psychological diseases, such as Alzheimer’s disease, cognitive function, depression, and schizophrenia. Other such key diseases include atrial fibrillation, irregular heartbeat, cancer, chronic kidney disease, cataracts, Crohn’s disease, pre-diabetes, allergies, and complications related to pregnancy.
More research in coming years could possibly let us know the extent to which fish oil is beneficial in these diseases.
Additionally, a critical viewpoint questions the need of omega-3s!
The scientific community across the world agrees that the effectiveness of fish oil has not been conclusively proven thus far. Results of various historical studies do not coincide and some recent studies continue to disapprove the originally believed effectiveness.
There are some fundamental questions, such as the overall need of the omega-3s, which are otherwise considered to be ‘conditionally essential’ for the human body. Furthermore, observations on certain traditional diets and ethnic communities indicate that omega-3s such as EPA and DHA are not present in the diets of several of these communities, which are considered to live longer and enjoy overall good health.
- American Heart Association, ‘Fish and omega-3 fatty acids’
- European Society of Cardiology, ‘A fish a day keeps the doctor away?’
- Health. Harvard, ‘Fish and fish oil: Good for most folks, but not all’
- Mayoclinic, ‘Omega-3 fatty acids, fish oil, alpha-linolenic acid’
- NIH.NLM, ‘Fish oil’
- NYTimes, ‘In Europe it’s fish oil after heart attacks, but not in U.S.’
- Raypeats.com, ‘ The great fish oil experiment’
- Weston A Price Foundation, ‘Precious yet perilous’
- Amit Khurana
Amit is a health enthusiast and believes in importance of ‘what we eat’ in maintaining it. He is an avid writer focusing on research based facts and opinions on food and nutrients. He likes to provide contrary perspectives to well inform his readers and continues to explore difference in beliefs on health and food in eastern and western part of the world. Amit is an occupational therapist and has worked in clinical settings of rehabilitation. He has extensive experience in researching and writing on scientific and commercial aspects of diseases, treatment, diagnostics, devices, and services in healthcare.