Do we have sufficient and robust data for or against taking fish oil?
Should we stop taking or continue recommending fish oil consumption? This is the key question.
It’s understandable that people don’t want to waste their money and consume something without clear health benefits. Many research studies paint a very confusing picture about the benefits of fish oil to our health. That is why I decided to research the true benefits of fish oil.
If you want to know more about the basics, I suggest reading the following article “Benefits of Fish Oil” before you go any further.
Data supporting the consumption of fish oil (n-3 Fatty acids)
Heart health benefits
Researchers studied the Greenland Eskimos (Inuits) and confirmed a very low rate of heart disease, reduced platelet activity (lesser chance of getting blood clots) and improved blood cholesterol levels compared to another Danish population.
They presented the hypothesis that marine n-fatty acids might be the reason for these positive findings in this population with high consumption of fatty fish such as seal.  These findings were also confirmed in other populations with a high volume of fish consumption such as Japanese and Alaskans.
Improvement of good- cholesterol
The majority of studies in non-diabetic patients treated with n-3 fatty acids revealed a 5–10% increase in HDL cholesterol levels.
Larger bad- cholesterol particles
One study showed that consumption of more than 3 g long-chain n3 polyunsaturated fatty acids (EPA and DHA) could result in larger low density lipoprotein (LDL) or bad-cholesterol particles and consequently reduce the less favorable small LDL particles .
N-3 fatty acids found in fish oil may also reduce the inflammatory factors. Research suggests that lower inflammation in the body especially blood vessels is better to our general health.
Hypertension (high blood pressure)
Improving insulin sensitivity
Sudden death and abnormal rhythm of heart
An Italian trial, confirmed a reduced risk of sudden death by 45% after suffering a heart attack and receiving highly purified n-3 fatty acids.
In an analysis of 30 high quality trials, examining the effect of fish oil on the heart rate. Fish oil supplementation of an average dose of 3.5 g/day in trials shown to reduce the heart rate by 2.5 beats per minute. This effect was not so prominent if the fish oil was taken for fewer than 12 weeks.
Plaque prevention and stabilization
Plaque is described as a deposit of fatty material on the inner lining of an arterial wall.
These deposits are characteristic of atherosclerosis or hardening of vessels. Studies showed that omega 3-fatty acids through their anti-inflammatory effects could not only prevent the plaque development but also contribute to plaque stabilization. 
Studies looking at 794,000 individuals suggested a moderate inverse association of fish consumption and omega 3 fatty acids with stroke. 
Data from the Physicians’ Health Study showed that fish consumption greater than once per month was associated with a lower heart failure risk.
Looking at 10 studies in patients with mood disorders receiving omega-3-fatty acids showed significant antidepressant efficacy of omega-3-fatty acids. 
A study examined the rate of advanced prostate cancer in 2268 patients aged 67-96 year old and found that men consuming fish oil (once a week or more) in later life had a lower risk of advanced prostate cancer.
A small study found that omega 6 fatty acids could modestly improve the dry eyes related symptoms. Administration of at least 112 mg of linoleic acid and 15 mg of gamma-linolenic acid twice daily for 45 days to achieve a satisfactory result were recommended. 
Data questioning the benefits of fish oil (n-3 Fatty acids)
A study on almost 12,500 patients with multiple risk factors for heart disease on daily treatment with n-3 fatty acids did not show any significant reduction of heart related deaths and complications. 
However, it is worth mentioning that the majority of these patients were already on an optimal treatment regime recommended for heart disease problems such as cholesterol and blood pressure lowering medications.
Direct evidence on the effect of omega-3-fatty acids on the incidence of dementia is lacking. The available data does not support using omega-3-fatty acids supplementation in cognitively healthy older people.
Ulcerative colitis and Crohn’s disease
Current available data does not support the use of fish oil in maintaining the remission of either ulcerative colitis or Crohn’s disease.
Numerous studies examined the effects of fish oil and n-3 fatty acids on multiple diseases and medical conditions. However, only a few of these studies had an acceptable quality and design. This is why a clear recommendation for or against taking fish oil in many cases is not possible.
Stronger data is available concerning the effects of fish oil in reducing triglycerides (fatty acids), inflammation, high blood pressure and improvement of HDL (good) cholesterol.
I am still in favor of consuming 3-4 portions of fish (fatty fish) every week. As you may already know, I always support eating fresh food over taking supplements or medications, except when absolutely necessary.
This amount of fish can deliver the appropriate quantity of proteins, vitamin D, iodine and many other minerals to the body.
Patients with diabetes, uncontrolled high triglyceride levels (200mg/dl) and multiple vascular diseases may need consumption of additional fish oil capsules on top of their regular fish intake.
Clearly, I am hoping to see better designed studies examining patients at low to moderate risk for vascular disease (not already on cholesterol lowering medication) and also in other medical conditions such as depression on higher dosage of n-fatty acids.
The appropriate dosage of fish oil in each individual is different and should be discussed with a lipidologist and treating physician.
Let me know what you think!
I would like to invite your comments on fish oil consumption. What are your thoughts and perspectives as a consumer or prescriber? Join our conversation, go to my Google + page and let me know what you think!