Fish Oil Supplements

By Ruth Trickey and Cara Tanner | August 2, 2011 | 1 Comment

Topics covered in this article

Essential fatty acids - EPA vs DHA
Understanding the label
        • ‘High potency’ fish oils
        • Enteric coating
Quality Standards for fish oils
Rancidity and fish oils
Fish – size really does matter
Environmentally friendly fish oil

Fish oils are becoming one of the most commonly prescribed supplements in the developed world. With increased incidence of cardiovascular disease, diabetes and mental health amongst the population, more individuals are seeking fish oils as a therapeutic agent. With hundreds of different types, strengths and brands of fish oils, it can be difficult to navigate the market and identify good quality fish oils at a reasonable price.
In the following article, we have tried to outline key features that distinguish one fish oil supplement from another and provide you with the tools to make educated decisions on which fish oil supplements are more suitable for you. We have also included information on what fish oils we stock at the clinic and the reasons why we have chosen to stock those brands.

Essential fatty acids – EPA vs. DHA

Fish oil supplements contain omega-3 fatty acids (also called essential fatty acids). These are a family of polyunsaturated fatty acids, called ‘essential’ because our bodies cannot produce them from other fats. We must therefore rely on dietary sources and supplementation in order to meet our daily requirements.

There are two main types of omega-3 fatty acids that are important for good health: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and each has a specific role.
The ratio of EPA to DHA in a fish oil supplement is often varied by the manufacturer to achieve different therapeutic actions in the body. This means that a consumer can choose or be prescribed the appropriate EPA and DHA concentration to achieve a targeted therapeutic outcome.

Fish oil supplements with a higher concentration of EPA have been shown to have a more anti-inflammatory action in the body, and at the clinic we will often prescribe this type of fish oil for a multitude of inflammatory conditions.
These include joint pain and arthritis, cardiovascular disease, hypertension and menstrual pain (dysmenorrhoea). They are also used to increase ‘good cholesterol’ (HDL), to decrease the incidence of and to reduce the complications of diabetes, assist in weight loss, and to maintain cognitive function and decrease the risk of developing dementia and Alzehimer’s disease.

DHA has a central role in brain health, mood and cognitive function. DHA is a major structural component in the phospholipid membranes of neurons and plays an important role in modulating neurotransmitters, which are chemicals that can influence mood, memory and learning, sleep and behaviour. DHA has also shown to influence neuron growth and regeneration.

Based on DHA’s role on brain health, practitioner’s in our clinic will often prescribe fish oils that at have higher concentrations of DHA for expectant mothers and during breastfeeding. During gestation, there is a higher requirement for omega-3 fatty acids because the developing baby is reliant on its mother for essential fatty acids for healthy brain, nervous system and eye development. Breast milk is also the primary source of the baby’s omega-3 fatty acids. The brain continues to develop rapidly from infancy through to adulthood, and supplementation during this time has shown to not only enhance learning in children and adolescents, but assist with mood and behavioural disturbances and patients with attention deficit hyperactivity disorder (ADHD). High DHA concentrated fish oils are also used for normal brain function in adults and for people with anxiety, depression and sleep disturbances.

Although in this article we have briefly outlined a few key differences between EPA and DHA, their therapeutic actions are very broad and are not limited to those listed above. For example, DHA also plays an important role in vascular health and reducing risk of cardiovascular disease. This is why most fish oil supplements with a high concentration of EPA will also contain a significant amount of DHA as well.

All fish oil prescriptions in the clinic are based on each patient’s clinical presentation and/or the underlying pathological changes associated with their condition.

Understanding the label

‘High potency’ fish oils
With an increasing number of fish oils available to consumers, it can be difficult to identify high-strength fish oils that are of high quality. Most fish oils will advertise that they are high potency containing 1000mg or 1500mg of fish oil per capsule, but what does this really mean?
The milligrams (mgs) of a fish oil supplement tells you the quantity of fish oil in the capsule but in no way can be used to determine the quality or the potency of the fish oil. It is the levels of EPA and DHA in the fish oil that determines its potency. Thus a 1500mg fish oil capsule may actually contain less EPA and DHA than a 1000mg capsule.

Fish oil capsule commonly contain 180mg EPA and 120mg DHA per 1000mg fish oils and are known as 18:12 fish oil. More concentrated forms are available and are usually around 300-400mg EPA and 200mg DHA per 1000mg fish oils.
Liquid fish oils generally contain relatively high concentrations of EPA and DHA per dose, however, taste and texture can be an issue for many people.

Enteric coating

1. We normally purchase capsulated fish oil supplements that are enteric coated for our patients 

Many fish oil supplements available to Australian consumers have an enteric coating, which will always be printed on the front of the fish oil container. Enteric coating is important in fish oil supplements, because it delays the breakdown of the fish oil capsules until it reaches the small intestine which is the primary site of fat digestion. This not only promotes optimal absorption, but also reduces the incidence of gastric reflux and ‘fishy burps’ after ingestion.

2. How enteric coating works

The breakdown of enteric coated supplements is primarily influenced by the variable pH within the gastrointestinal tract. The gastric environment (stomach) is highly acidic and has a pH of approximately 0.8, whereas the small intestine has a relatively alkaline pH of 7.0.
Enteric coating is designed to stay intact in the stomach, but become more soluble and break down when it is exposed to a more alkaline environment of the small intestines.

Quality standards

When looking at purchasing a fish oil, some of the most important questions you need to ask are, how are the fish oils manufactured and what are the quality standards that the manufacturer is using?
There are several quality standards that exist for fish oils, including Norwegian Medicinal Standard, the European Pharmacopoeia Standard, the United States Pharmacopoeia, and the voluntary standard established by the Council for Responsible Nutrition (CRN). These standards guarantee a certain level of quality by outlining the maximum level of toxins and contaminants (including heavy metals and pesticide residues), and oxidation markers (indicates how rancid the oil is) in a fish oil.
However, there is a considerable difference between each of the above standard guidelines, with some being significantly more stringent than others.

CRN realised the importance for purity of fish oils and released a voluntary quality standards monograph for EPA and DHA. At MHHG, we choose to buy only from companies that conform with, or exceed the voluntary quality standards for fish oils outlined by the CRN and we are particularly concerned that those patients who are pregnant, have serious medical conditions such as cancer, or those who are prescribed fish oils for long periods of time are prescribed fish oil supplements that are the cleanest and best quality that we can source. The CRN standards are more stringent than any single regulation in the world and help to ensure that consumers have access to products of highest quality.

Currently companies here in Australia that sell over-the-counter products are required to comply with the compositional guidelines outlined by the Commonwealth Government regulatory body that is responsible for the safety and quality of therapeutic agents, Therapeutic Goods Administration (TGA). These guidelines are based on the US and European Pharmacopoeia standards. The maximum levels set by the TGA for fish oil contaminants, such as heavy metals (e.g. lead, mercury, cadmium and arsenic), oxidation markers, and pesticides, are notably higher than those outlined in the CRN standards. This means that the majority of over-the-counter products, which do not comply with the CRN standards, contain considerably higher levels of toxins and contaminants.

Most reputable companies, when contacted, will disclose what quality standard their fish oils comply with, and can provide details of the levels of heavy metals, oxidation markers, pesticides and dioxin residues in their fish oils.

The following table gives a comparison between the TGA guidelines and the specifications as supplied by the companies that the supply fish oils that we currently use at the clinic. We routinely check with our suppliers to confirm that there have been no changes in fish oil sources or quality control.

Purity standards Comparison Chart

Rancidity and fish oils

Fish oils are particularly sensitive to oxidation. Oxidation products are not naturally found in fish oil, but are formed if the oil is handled incorrectly. Oxidation is a chemical process which indicates that the fish oil is becoming rancid. Many factors can cause fish rancidity. These include exposure to oxygen, heat and sunlight; or the process can occur because of improper handling and storage. Because fish oils are so sensitive to oxidation, every step of the manufacturing process needs to be highly controlled. Low oxidative parameters also ensure a long shelf life of the fish oil.

1. How do you know whether your fish oils are oxidised (rancid)?

Sometimes you can determine the level of oxidation from the smell and taste of your fish oils. To check the smell, taste and consistency of your fish oil, chew one of your fish oil capsules.
The fish oil should not have a strong fish or rancid odour, nor should they have a strong fishy taste. Fresh fish oil has a fresh aroma that is not overly fishy.

Another way to determine the level of oxidation of the fish oil is the oxidation markers. These are not included on the label of the fish oils, but can be obtained if you contact the fish oil manufacturer. Higher quality fish oils will have much lower peroxide, p-Anisidine and acid values. You can use the above quality standards chart to use as a guideline. Ideally, peroxide values should not be greater than 5meq/kg. Most reputable companies will provide you with these details.

2. What is added to stabilise fish oils?

High quality fish oil manufacturers will also add vitamin E during production to improve the stability of the fish oil and reduce the risk of oxidation. Added vitamin E will often be listed on the fish oil label. Adding vitamin E to fish oils, particularly mixed tocopherols (blends of different types of vitamin E), has shown to increase oils stability by up to 50%. Vitamin E can be added to fish oil, but may not necessarily be written on the label, therefore you might need to contact the manufacturer for these details.

3. What can you do to prevent your fish oils from going rancid?

  • Keep all fish oil liquid (non-encapsulated) refrigerated once opened and ensure cap is well sealed to reduce exposure to oxygen
  • If you have a liquid fish oil, use within 3 months of opening the bottle
  • Refrigerate fish oil capsules if your home reaches temperature above 30 degrees Celsius
  • Never put fish oil containers in direct sunlight, and always store them in a cool cupboard
  • Always check the expiry date and never consume expired fish oils
Fish – size does really matter

When considering fish oil, it is important to know what type of fish is being used to manufacture the oil. At the clinic, we primarily focus on sourcing fish oils which are manufactured using only small fish, such as anchovies and sardines.

Small fish like anchovies and sardines naturally contain lower levels of contaminants. This is because they are at the bottom of the aquatic food chain and therefore do not accumulate heavy metals (e.g. mercury) and other contaminants as much as more carnivorous fish. In addition, they have a short life span and their exposure to these heavy metals is significantly less.

Environmentally friendly fish oil

In 2009, the combined total of fish oil produced by the five main exporting countries (Peru, Chile, Iceland, Norway and Denmark) was approximately 530 000 tonnes. It is hard to look at this figure and not question what kind of impact this is having on the environment.
When deciding on a fish oil supplier, our priority was to find a company that not only sourced their fish from sustainable fisheries but were also committed to making the entire manufacturing process environmentally friendly from fish harvesting to the finished omega 3 products.

After researching fish oils available on the market, we have decided to stock oils from two leading fish oil suppliers; EPAX and Ocean Nutrition Canada. These companies are not only industry leaders in terms of product purity, but they also have a strong commitment to environmental sustainability.

What makes these companies unique?

1. Source their crude fish oil (raw material) from Peruvian Fisheries.

The Peruvian coastal waters are not only known for having one of the world’s richest marine habitats, but Peru is credited with having a highly regulated governmental fishery surveillance system. The Peruvian fisheries are regulated and protected to ensure bio-diversity and sustainability of their marine waters. They regulate the minimum fish size, the number of juvenile fish caught, and limit their catch to two times a year and suspend fishing during spawning season to prevent over-fishing.

2. They use 100% of their crude fish oil (raw material)

Any oil that is not used to manufacture fish oil concentrates for supplements are used for biofuel and fertiliser products. These companies are so committed to environmentally sustainable practices, that they use these byproducts to run their facilities and offices.

For more information on these companies’ environmental commitment, please click one of the below links.

Ocean Nutrition Canada

MHHG is not responsible for the content of external Internet sites

Contact you naturopathic practitioner for more information on fish oil supplements, and which fish oil may be more suitable for you.


Other articles on fish oils:

Impact of fish oils on learning and behaviour in children 

Posted in Fish Oils

1 Comment

Ang Gen (8 months ago)
Having just bought Ruth's book on Women, Hormones & the Menstrual Cycle pubished 2011 in order to use as reference for my studies in herbal medicine i shall treasure it forever & feel it well worth the money paid using the Book Depository and with free postage from Aus to UK was brilliant. I just would like to add that in UK i buy my pure Omega 3 liquid fish capsules in from and no fishy after taste as it's got peppermint flavour and is free from pesticides.

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