Fish Oil – Benefits and Side Effects

Fish Oil – Benefits and Side Effects

Fish oil is on a roll.

It’s difficult to open up a health or fitness magazine, browse the Internet or turn on the TV without seeing yet another piece on this “wonder” supplement. The health claims made in the media and online are often as amazing as the idea that we can distill down the oil of hundreds of fish into a single capsule: Reduce heart disease! Prevent cancer! Stave off depression! Stop arthritis! Improve your mood!

Not since Linus Pauling published his work on the benefits of Vitamin C (which has come under increased scrutiny by scientists in the past few decades), has there been so much buzz around a single supplement.

So before we dig into some of the possible benefits (and the potential side effects) of fish oil, let’s take a look at how we got here in the first place.

A Brief History of Fish Oil

The whole fish oil story started with a simple observation: People who had diets high in certain types of fatty, cold-water fish appeared to have lower rates of heart disease than other populations who ate less fish. The traditional Japanese diet, for example, contains large amounts of fish, as do certain Norwegian and arctic populations (like the Inuit.)

Scientists were intrigued enough with this correlation that they started to conduct studies to see if whether including more cold-water fish in the diets of people who don’t normally eat fish, could produce a similar benefit. Their results, while not conclusive, did find a strong correlation between the consumption of certain fats contained in fish, and decreased risk for certain form of heart disease.

So what’s so great about fish?

Aside from being high in protein and low in cholesterol, most species of fish are high in three kinds of essential, non-saturated fatty acids called Omega-3s: α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). “Essential” means that you’re body can not create these fatty acids on it’s own — you have to include them in your diet.

It’s these fatty acids that scientists believe contribute to the health benefits of fish consumption. As research around Omega-3s and their health benefits began to emerge, fish joined the ranks of olive oil as a source of “healthy fats” that may have protective qualities for the body. In fact, results were encouraging enough that in 2004, the U.S. Food and Drug Administration gave a “qualified health claim” to EPA and DHA, saying that “supportive, but not conclusive” research had shown that consumption of EPA DHA may reduce the risk of coronary heart disease.

Fish oil as a medicinal treatment has actually been around for centuries. Cod liver oil has been a folk remedy for all kinds of aches and pains. However, fish liver oils are also relatively low in Omega-3s and high in Vitamin K, which can be toxic in high doses.

In the past 20 years, manufacturers have gotten much better at purifying and distilling down fish oil, to the point where they can actually standardize and control the amount of Omega-3s in the finished product. This has allowed people to get more Omega-3s in their diet, even if their actual fish consumption is relatively low. It’s also replaced cod liver oil as a safer, more concentrated form of the healthy fats in fish.

Understanding Omega-3s

Omega-3

Omega-3s are interesting because there are only a few sources of these fatty acids in nature. Fish by far has the highest concentrations, and then flaxseed and then smaller amounts in things like walnuts and almonds.

Omega-3 is an essential unsaturated fatty acid, meaning that along with Omega-6 fatty acids, your body requires a certain amount of it, in the proper ratio to other fatty acids, for proper cellular function. The problem is that because the typical Western diet is so high in grain and corn (which is rich in Omega-6 fatty acids), the ratio of Omega-6 to Omega-3 is often between 10:11 to 30:1, when it ideally should be 5:1. Your body needs Omega-6s, just not in the large quantities that are typically characteristic of modern, Western diets.

There is some research to indicate that this high Omega-6-to-Omega-3 ratio could be contributing to a whole host of health issues, especially inflammatory disease like arthritis and auto-immune disorders like allergies.

Even societies (like the Japanese) that have traditionally included large amounts of fish in their diet seem to be experiencing some of the negative effects of this imbalance of Omega-3s-to-Omega-6s as they have shifted toward a more Western diet, that contains higher amounts of grain and corn-fed beef.

Health Benefits of Fish Oil and Omega-3s

While the initial focus of research around Omega-3s focused on their potential to reduce the risk of heart disease, studies over the past few years have also suggested (though not conclusively proven) a wide-range of possible additional health benefits to fish oil and Omega-3 supplementation, including:

  • Improvements in circulatory health
  • Decreased risk of stroke
  • ​Decreased blood pressure
  • ​Reduction in blood triglyceride levels
  • ​Improvements in mood and cognitive ability
  • ​Mild anti-depressant effects
  • Improved immune function in infants
  • Anti-inflammatory properties that may help reduce the symptoms of rheumatoid arthritis or neck, back and joint pain

Fish Oil and Heart Disease

Heart Disease

There is a growing body of evidence that suggests that fish oil supplementation may reduce the risk of heart disease.

The actual mechanisms are complex, since fish oil supplementation seems to reduce certain precursors to heart disease like blood triglycerides, while also improving circulation and reducing blood pressure. This may have a preventative effect, although it is not a treatment for existing heart disease. However, a 1999 study of patients with myocardial infarction, found that treatment of 1 gram per day of Omega-3 fatty acids reduced the occurrence of death, cardiovascular death and sudden cardiac death by 20%, 30% and 45% respectively. Furthermore, a 2007 study found that supplementation with EPAs from fish oil decreased the thickness of the caratid arteries in Japanese men with unhealthy blood sugar levels and improved blood flow, versus those who received a placebo.

But before you get too excited, you should also know that Omega-3s are not for everyone — especially those with certain pre-existing heart conditions. Individuals with congestive heart failure, chronic recurrent angina or evidence that their heart is receiving insufficient blood flow are advised to talk to their doctor before taking fatty acids, since they may actually aggravate, rather than treat, these conditions. In some cases, this can be fatal.

Fish Oil Health Claims That Still Require Additional Research

Although there is strong clinical evidence that suggests consuming omega-3 fatty acids can reduce blood pressure, triglyceride levels, sudden heart attack, inflammation and rheumatoid arthritis, there is also a long list of health claims of fish oil that are less conclusive and require additional clinical research. These include:

  • Age-related macular degeneration
  • Agina pectoris
  • ​Asthma
  • ​Atherosclerosis
  • ​Attention Deficit Hyperactivity Disorder (ADHD)
  • Learning and Behavioral Disorders
  • ​Bipolar Disorder
  • ​Cancer Prevention
  • ​Cardiac Arrhythmias
  • ​Colon Cancer
  • Acute Coronary Disease​
  • ​Cystic Fibrosis
  • ​Dementia
  • Depression
  • Eczema
  • Increase Energy Efficiency and Metabolism
  • ​Epilepsy
  • ​Increase Infant Body Mass/Growth Rates
  • Improved Immune Function​
  • ​Inflammatory Bowel Disease (IBD)
  • ​Lupus
  • Prostate Health
  • ​Psoriasis
  • ​Schizophrenia
  • ​Stroke Prevention
  • ​Diabetes
  • High Blood Cholesterol

Recommended Dosage of Fish Oil

In healthy adults, the American Heart Association recommends individuals eat two servings of fish a week. Fatty fish, such as anchovies, carp, bluefish, catfish, halibut, salmon, herring, lake trout, whitefish, mackerel, pompano, tuna and striped sea bass, are the best. The World Health Organization recommends consuming 0.3-0.5 grams of EPA plus DHA daily and between 0.8 to 1.1 grams of alpha-linolenic acid (ALA) per day. Women who are pregnant or nursing should consult a doctor regarding fish consumption, because of concerns around heavy metal and PCB contamination — especially if you are eating Great Lakes fish. Also, if you have fish-related food allergies, you’ll obviously want to skip the fish oil supplements.

How much fish oil is that? It really depends on the concentrations of EPA and DHA in the fish oil capsules you purchase.

For example, a single serving (one fish oil capsule) Nature’s Bounty Omega-3/Omega-6 Fish Oil Capsules(1200 mg) contains 216 mg of EPA and 144 mg of DHA. To reach a half gram of EPA and DHA, you’d need to consume around two capsules a day. Some capsules have higher and lower amounts of EPA and DHA, so it’s really necessary to read the label. Remember, there is 1000 mg in a gram. So 0.5 grams is about 500 mg each of DHA and EPA.

Non-Animal or Non-Fish Sources of Omega-3 Fatty Acids

If you are a vegan or vegetarian and do not consume fish, there are some alternative sources of Omega-3 fatty acids, in particular ALA.

Non-animal sources of ALA include rapeseed oil (canola), soybeans, walnuts, perilla, hemp, chia (yes, it’s more than just a pet) and the big, ALA powerhouse, flaxseed.

However, unlike the Omega-3 fatty acids in fish, ALA is a precursor to DHA and EPA. This means the body has to convert the ALA into DHA and EPA. Unfortunately, the body isn’t particularly effective at doing this, so the amounts of DHA and EPA that become available to the body from the ALA in flaxseed is substantially less than with fish oil. Therefore, you may need to consume higher amounts of ALA from flaxseed or other vegetarian sources than with fish to achieve the recommended EPA and DHA intake levels.

There is some preliminary research that has associated ALA intake with increased risk of macular degenerationand prostate cancer. However, in the case of the prostate cancer research, this was a meta-study, which examined other studies to arrive at its conclusions. Meta-studies continue to be somewhat controversial from a methodology standpoint, so you should be careful about drawing too many conclusions from them.

Potential Side-Effects of Fish Oil Supplementation

The US Food and Drug Administration (FDA) considers intake of up to 3 grams of omega-3 fatty acids from fish as generally safe. There are a few warning however. There is a slight risk of increases in blood sugar levels among diabetics. Omega-3 fatty acids may also increase the risk of bleeding (since they thin the blood), although there is little evidence of significant risk at lower doses (under 3 grams.) Extremely high levels may increase the risk of hemorrhagic stroke, and high level fish oil intake has also been associated with nosebleeds and blood in the urine.

Also, make sure your doctor knows you are supplementing with fish oil, especially if you are undergoing a surgical procedure, since fish oil can reduce blood clotting.

There may be some stomach or intestinal upset with fish oil, including diarrhea, increased burping, acid reflux and indigestion, and abdominal bloating. Taking fish oil supplements with food, versus on an empty stomach, can help prevent some of these minor — but annoying — side effects.

As always, it’s a good idea to consult with your physician before starting any supplementation program.

My Own Experience With Fish Oil

I personal supplement with 3-4 grams of fish oil a day, taken in two doses — two grams in the morning with breakfast and another two with dinner or before bed.

I started taking it primarily for the cardio-vascular benefits, but discovered that it appears to have a positive (though completely anecdotal) additional benefit. I’ve had a moderate-to-severe problem with neck pain for about eight years and tried everything from muscle relaxants to a chiropractor with mixed results. After about two months of fish oil supplementation, I found that my neck pain had nearly disappeared.

As an experiment (completely non-scientific), I stopped fish oil supplementation for about six weeks, and began experiencing a return of neck pain symptoms. When I resumed supplementation, the symptoms subsided. This could, of course, have been the result of a placebo effect, so it’s not conclusive.

However, in my case, I would prefer to take the fish oil capsules (even if they are acting as a placebo) than over-the-counter anti-inflammatories, which have never been particularly effective at reducing the neck pain in the past.

There also appears to be some clinical research to support my own experiences with reduced neck pain as a result of fish oil supplementation. A 2006 study published in the journal Surgical Neurology by researchers from the University of Pittsburgh Medical Center found that fish oil supplementation was as effective in reducing acute and chronic non-specific neck and back pain as non-steroidal anti-inflammatory drugs (NSAIDs) like ibuproben, with less serious potential for side effects.

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