Are you eating enough Omega-3s?

The other day, I started thinking about seeds and how I push my oncology patients to add them to their smoothies as a source of healthy fat and protein.

Then I started thinking specifically about flax & chia seeds as well as their omega-3 content.

Every week, I teach a “Nutrition During Chemotherapy “class and in last week’s class, I asked the audience what are the best sources of omega-3 fatty acids?  There are only 4 really good sources!

No one really knew, which is totally fine.

But the answer is… fatty fish, walnuts, flax & chia seeds.

This led me to think, is the 1 tbsp of flaxseed meal that I add into my oatmeal every morning even giving me enough omega-3’s daily?

And now this brings me here, to this article and the reason why I wanted to write about omega-3 fatty acids.

I did a lot of research and I learn new things every day as a dietitian, partly because nutrition is always changing and partly because there is just so much to know!

Let’s start off with our omega-3 basics.

Omega-3 fatty acids are a type of polyunsaturated fatty acid that is essential for us, meaning we need to obtain them from the diet in the foods listed above.

According to the National Institute of Health (NIH), there are several omega-3 fatty acids but the ones that have been researched extensively include alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

ALA is the only omega-3 fatty acid that is essential. Our bodies can convert ALA to EPA & DHA.

Omega-3 fatty acids are an important part of the membranes that surround all of our cells and also function in our immune system, heart, blood vessels, and lungs.

EPA & DHA are two omega-3 fatty acids that seem to provide the most benefits, with current on-going research.  EPA & DHA are involved in lowering triglyceride levels, decreasing cholesterol, modulating inflammation, reducing the risk of heart attack and even preventing depression (Memorial Sloan Kettering Cancer Center).

ALA, the other omega-3 fatty acid, is not biologically active in the body until it is converted to EPA and/or DHA.  According to the NIH, the human body is inefficient at this, the conversion is around 10-15%, which is really little!

ALA, when not converted to EPA & DHA, is just stored or used as energy like other fats in the body.

Think about it, if EPA & DHA are the best omega-3 fatty acids, then we want more of this in our diet! 

Stay with me, it’s about to get even juicer.  

Remember the four main food sources of omega-3’s?  The ones no one in my class knew?

Yes, yes…fatty fish, walnuts, chia & flax seeds. 

Well, it’s pretty much the fatty fish that have the highest EPA & DHA.

Flax seeds, chia seeds & walnuts have a good amount of the omega-3 in them but this is mostly ALA and remember the conversion from ALA to EPA & DHA is quite low. 

For example, 1 oz of chia seeds (2 tbsp) has about 5.06 g of ALA.  At a 10% conversion, this gives us 506 mg of EPA & DHA. 

So hold up, something else I found that was pretty dang confusing was the amount of omega-3’s we need in our diet.

According to the National Academy of Medicine, there is an established Adequate Intake (AI) for omega-3’s.  AI is the amount that ensures nutritional adequacy, not the recommended dietary allowance (RDA).  AI’s are usually developed when research is insufficient to create an RDA.

The AI’s for omega-3 fatty acids are:

1.6 gm for males aged 19+

1.1 gm for females aged 19+

But, this AI only includes the amount of omega-3 fatty acid for ALA because only ALA is essential.

So even though EPA & DHA are the stars of the show, we do not have sufficient evidence to give a daily requirement.

Some organizations agree that 250-500 mg of combined EPA & DHA is a good amount to maintain overall general health. 

Back to fatty fish.  Remember how I said fish is a great source of omega-3, particularly EPA & DHA? 

If there is anything you need to take away from this article, then it’s exactly this!

Eat more fish!

3 oz of cooked wild Atlantic salmon has 1.22 g of DHA and 0.35 g of EPA. 

Try to make a goal of eating fish such as herring, trout, and Atlantic mackerel at least twice per week. 

The last thing I want to add is the omega-3, which is ALA, in flax & chia seeds are still very important to our bodies. As mentioned earlier, 2 tbsp of chia seeds will give us about 506 mg of EPA & DHA, which is the value most organizations agree is currently sufficient for our bodies based on current evidence.

Chia & flax seeds are also a great source of protein and fiber in the diet.  They also have other different nutritional components that can aid in health promotion and disease prevention.

It’s a lot easier to add chia & flax seeds to our smoothies, oatmeal, cereal, yogurt, etc. and grab a few walnuts as a snack than eating fish consistently each week for most people.

With this said, I shall continue with my flaxseed meal in my oatmeal every morning, remembering to add an amount closer to 2 tbsp!


Memorial Sloan Kettering Cancer Center

National Academy of Medicine


Leave a Reply