Nutrition Basics 2: Omega-3 Fatty Acids


Salmon: a source of omega-3s
By now, I think most people have heard at least something about Omega-3s, which are a type of fat. But I'm going to delve a little deeper..

Omega-3s Basics
Omega-3s are a type of unsaturated fat, the "good" fat.

You may have also heard of Omega-6s or Omega-9s. They are also unsaturated fats. 

If you want to get into science, Omega-3s have a double bond between two carbon atoms at the omega-3 position (which means that the third carbon from the end of the fat chain not attached to a glycerol backbone).

When talking about Omega-3s, you may have heard of specific fats, like alpha-linolenic acid (ALA), Eicosapentaenoic Acid (EPA), and Docosahexanoic Acid (DHA)

These are different molecules, but they are grouped together because they all have a double bond in the omega-3 position. However, one Omega-3 fat is not the same as another Omega-3; you don't need to eat all of them... 

Essential Fats
As I mentioned in my Macronutrients post, there are two essential fats: alpha-linolenic acid (ALA) and linoleic acid. Alpha-linolenic acid (ALA) is an Omega-3 fat and linoleic acid is an Omega-6.

They are called essential fats because they are the only 2 fats that your body cannot make but that it needs to eat. 

EPA & DHA often get a lot of talk in the media, but they are not considered essential. Your body may be able to make EPA and DHA from ALA, if your body has enough ALA.

Sources of Omega-3s
Most people have heard fish is a good source of Omega-3s,but there are plenty of vegan sources. In fact, vegan sources are more likely to contain essential ALA, whereas fish contain more EPA and DHA.

For example, ¾ cup of cooked black-eyed peas contains 0.11 g ALA. 3 ounces of tilapia contains just 0.04 g ALA.  The peas contain no EPA or DHA, but the tilapia contains 0.12 g DHA. 


Other vegan sources of Omega-3s include soy (tofu, soymilk, edamame), beans, almonds, chia seeds, flax seeds, pumpkin seeds, pecans, walnuts, canola oil, wheat germ, and winter squash. Silk also makes a soymilk with extra Omega-3s from algal oil. 


If you’re vegetarian, eggs contain small amounts of Omega-3s. Some brands sell eggs with higher levels of Omega-3s depending on what they feed the chickens. 

The Dietitians of Canada put together this great chart with Omega-3 sources. 

Omega-3 Supplements
If you don't eat foods that contain ALA, you may want to take an omega-3 supplement. There are vegan omega-3 supplements available from flax seed oil (ALA), walnut oil (ALA), and algal oil (EPA and/or DHA Omega-3s). 

It's relatively safe to take an omega-3 supplement. The most common side effect is burping up a fishy taste (for a fish oil supplement). Another potential side effect is diarrhea, but was seen in <7% of people studied. 

That said, it's always good to talk to a healthcare professional who knows you and your situation before starting any new supplements. 

Potential Benefits of Omega-3s 
There is a lot of research on the use of Omega-3s to prevent or treat diseases, such as asthma, heart disease, and depression. However, the National Institute of Health says the results are still "not completely clear."

For example, this article looked at multiple studies on treating depression with Omega-3 supplements. One study found patients felt better after 4 months of 10 grams of EPA and DHA a day. Another study found only 2 grams per day was enough, but a third study found 2 grams didn't work. 

Again, you should discuss it with your doctor. Your doctor can help you discuss the pros and cons. Taking 10 grams of Omega-3s may relieve your depression, but adding those 10 extra grams of fat might also make you gain weight.


Readers, what's your favorite Omega-3-containing food?

Comments

Popular posts from this blog

Understanding the Alphabet Soup of Nutrition Credentials

FAQs about Intuitive and Mindful Eating