Omega 3 Supplements and Oils Part 1 - Overview
What are the purpose and scope of this project?
We have allocated one month to carry out research into omega 3 supplements.
We aim, using published scientific research, to answer a series of questions relating to the purpose and effectiveness of different types of omega 3 supplements that are widely available.
We are not generally researching, or presenting information about, individual supplement products or specific brands. We do, however, discuss specific products briefly where they are relevant to the context. We may in the future evaluate specific products and brands and, if appropriate, we may recommend some of those products.
What types of omega 3 supplements are available?
We shall consider three types of omega 3 supplements. Firstly, we shall deal with fish oil supplements, which contain both EPA and DHA. Secondly, we shall look at algae supplements, which typically contain either EPA or DHA, but in some cases contain only ALA in significant quantities. Finally, we shall consider the small group of seed oils that contain high levels ALA, but not EPA and DHA.
Functional foods, enriched during the manufacturing process with n
-3 fatty acids or other nutrients, could be viewed as a vehicle for supplementation. We are excluding such foods from our analysis on the basis that they are essentially processed foods and it is difficult to assess their overall impact on nutrition.
When we talk about omega 3 supplements we often mean fish oils, which contain high levels of EPA and DHA and which are by far the most popular n
As explained elsewhere, we treat EPA and DHA as essential to the human diet. A number of prominent lipid scientists, including the omega 3 pioneer William E M Lands, support this view. The study by Muskiet et al, published in The Journal of Nutrition in 2004, concluded that DHA is "likely to be essential".
The body can convert ALA into EPA, but only at a low rate. It can also convert EPA into DHA, but at an even lower rate. These two important fatty acids are therefore best obtained directly through our diet.
Go to Part 2 - Fish Oil Supplements
Algae have been proposed as an alternative to fish oil supplements as they contain EPA and DHA (although most algae do not have significant quantities of both) and are acceptable to vegetarians. In fact microalgae or microphytes are the single source of the n
-3 PUFAs found in fish, which do not make n
-3 but obtain it through their food.
, a type of seaweed used in Japanese recipes, is a good source of EPA while other algae, such as Schizochytrium
, are good sources of DHA. Both are available in supplement form.
Microalgae such as spirulina
are widely marketed as nutritional supplements. Spirulina
is a member of the blue-green algae family, more strictly classified as a type of bacteria in recent years. Although it contains a range of valuable nutrients, spirulina
does not contain significant quantities of EPA and DHA.
Go to Part 3 - Algae Supplements
Some seed oils, unlike most that are widely used in cooking, contain high levels of ALA and can therefore help to improve our n
-3 to n
The benefits of EPA and DHA to human health are clear but the case for ALA, although ultimately compelling, is harder to establish. That is because ALA does not perform the same sort of specialized physiological functions delivered by EPA and DHA.
ALA nevertheless has an important functional role and also most likely has a direct impact on DHA status (see below), especially when supplied in the context of a reduction in the n
-6 PUFAs LA and AA. ALA is also effectively converted by the body into EPA, which has an important role controlling inflammation via the eicosanoids that are derived from it.
Go to Part 4 - Seed Oils
What research material have we consulted for this project?
We have listed the research article citations and books on a separate page.
Go to Part 5 - Research Material
Return to the Omega 3 Supplements and Oils Introduction