Omega-3 is a type of fat you have probably all heard about, especially with the focus shifting to including more healthy fat in the diet. Omega-3 is a sub-type of polyunsaturated fat (PUFA), along with omega-6. PUFA’s are fats that have two or more double bonds between the carbon atoms. This means that there are less hydrogen atoms than you would find in saturated fat, where all the carbon atoms are bound to a hydrogen atom1.
Omega-3 and omega-6 are essential fats, so you have to get them from your diet as your body is unable to make them. Only plants (including marine phytoplankton) are able to make these fatty acids2. You probably also know that omega-3 has numerous health benefits for all stages of the life-cycle but, what you probably don’t know is that there are different types of omega-3…
Alpha-linolenic acid (ALA):
- This fatty acid has 18 carbons2.
- ALA is found in plant-sources, such as walnuts, canola oil and chia seeds1.
- It is metabolized by animals to form EPA and DHA.
- It does not have as potent health effects as EPA and DHA, however it is still important to include sources of ALA in the diet1,2.
Eicosapentaenoic acid (EPA):
- This fatty acid has 20 carbons2.
- EPA is found in fatty fish and marine algae2.
- Only a small amount of EPA is converted from ALA in humans, so it is important to include preformed sources of this in the diet (i.e. fatty fish) in order to achieve adequate levels in the blood and avoid a deficiency2.
- EPA is precursor to many different molecules that play important roles in the functioning of various different systems in the body3.
- EPA helps to control inflammatory responses, regulates blood coagulation and plays a role in determining which genes are turned on and off3.
Docosahexaenoic acid (DHA):
- This fatty acid has 22 carbons2.
- DHA is also found in fatty fish and marine algae2.
- As with EPA, only a small amount of DHA is converted from ALA in humans, so it is important to include preformed sources of this in the diet.
- DHA forms a structural component of every cell in the body, where significant amounts are found in the heart, brain, eyes, nervous system and the testes2. The presence of DHA in the cell walls helps to make them more flexible, allowing proteins in the membrane to control the inflow and outflow of important cell components which leads to the efficient operation of the cell3.
- DHA is a precursor to many different molecules that play important roles in the functioning of various different systems in the body3.
- DHA also works with EPA to control inflammatory responses, regulate blood coagulation and play a role in determining which genes are turned on and off3.
As we are unable to make omega-3 in our bodies, we need to make sure that we include them in our diets. There are different types of omega-3 and it is important to consume sources of all of these.
1. Escott-Stump, Sylvia. Nutrition and Diagnosis-Related Care. Baltimore : Lipincott Williams & Wilkins, 2008.
2. DSM. Benefits of optimal omega-3 intake and status. August 2016.
3. Omega-3s, Always. Heart Health Benefits of EPA and DHA. September 2015