By now, omega 3 fats are a household term…but how much do you really know about them? What are they, and should you be consuming omega 3 fat rich foods on a daily basis? What about a supplement…do you need it?
As a dietitian who does anti-inflammatory nutrition, omega 3 fatty acids are an important part of my practice. So let’s take a deep dive into what they are…and what they can do for you.
What is an Omega 3 fat?
There are three different types of fatty acids: monounsaturated fatty acids, or MUFAs, polyunsaturated fatty acids, or PUFAs, and saturated fatty acids. We don’t have a nickname for that one! Saturated fatty acids are called saturated because fatty acid structure is saturated with hydrogen molecules and therefore, has no double bonds. This makes saturated fatty acids solid at room temperature – think butter and coconut oil. MUFAs and PUFAs have double bonds that cause crinkles in their structure that don’t allow the molecules to line up tight, so they are liquid at room temperature instead of solid. Monounsaturated fatty acids have just one double bond and polyunsaturated fatty acids – you guessed it – have more than one. Omega 3 fatty acids (FA) are a polyunsaturated fatty acid. The Omega 3 comes from the placement of the first double bond in the structure – it comes at the 3rd position. SCIENCE!
Omega 3’s are considered an essential nutrient, essential means that the human body can’t make them, so you have to eat them.
The three most common types of omega-3’s include:
- alpha-linolenic acid (ALA)
- eicosapentaenoic acid (EPA)
- docosahexaenoic acid (DHA)
ALA is the most common form of omega 3 found in plant food. ALA can be converted into its biologically active cousins EPA and DHA, however for some this conversion is not efficient enough. However, EPA and DHA can be directly obtained from food and supplements.
How much Omega 3 Fat do I need in a Day?
We know that we absolutely need to eat omega 3 fats, so how much we you actually need? Adult men require 1.6 g/day of ALA, while women require slightly less at 1.1 g/day. Technically, only ALA is considered an essential nutrient as ALA can be converted into EPA and DHA. However, as I mentioned, this conversion sometimes isn’t the most efficient.
It’s worth noting that pregnant women require more ALA at 1.4 g/day. What’s more, the American Pregnancy Association recommends that pregnant women consume a supplement containing at least 300 mg of DHA. While most pregnant women know about their prenatal vitamin requirements, not everyone is aware that they need omega 3 fatty acids!
Some research shows that men convert only 8% of ALA to EPA and 0-4% to DHA, while women may be able to convert 21% of ALA to EPA and 9% to DHA. This difference between men and women, is thought to be due to the effects of estrogen on the body.
Is there any way this conversion rate is altered? Well, consuming more omega 6 FA can alter the conversion of ALA to EPA and DHA. Omega 6 FA compete with ALA, as they use the same pathway in metabolism. So, more omega-6 may mean less conversion of ALA to EPA and DHA. On the other hand, consuming more omega-3 FA may increase the production of EPA and DHA.
Omega 3 Fat Rich Foods (list)
What are some examples of foods that contain omega-3’s? ALA typically comes from plant sources, while EPA and DHA come from sources such as fatty fish and algae. The following is a list of foods that are a good source of omega-3’s:
- Flax seeds (1 tbsp/15ml) 35 g ALA
- Chia seeds (1 tbsp/15ml) 2.53 g ALA
- Hemp seeds (1 tbsp/15ml) 0.86g ALA
- Flaxseed oil (1 tbsp/15ml) 7.26 g ALA
- Walnuts (1/4 cup/60ml) 5.14 g ALA
- Canola oil (1 tbsp/15ml) 1.28 g ALA
- Fatty fish
- 3 ounces (85g) wild salmon = 1.22 g DHA and 0.35 g EPA
- 3 ounces (85g) mackerel = 0.58 g DHA and 0.43 g EPA
- 3 ounces (85g) herring = 0.94 g DHA and 0.77 g EPA
Benefits of Omega 3 polyunsaturated fats
Omega-3 FA have many roles in the body, but one important function includes membrane structure. Each cell has a membrane, like we have skin. The membrane holds everything in place and acts as a barrier between the inside and outside of the cell. Once integrated in the membrane, omega-3 FA can affect the fluidity, permeability, flexibility and signaling pathways of the cell. In fact, DHA is important in the cell membranes of the retina and brain. DHA is high in the retina of the eye and even protected when levels of omega-3 decrease in the body, suggesting that DHA is important for the function of the retina and our eyesight.
Omega 3 for Brain Health
DHA is also involved in the development of the brain. This is why it is important that pregnant women ensure they are getting enough omega 3. Most of the accumulation of DHA occurs in the last trimester of pregnancy, making this period critical for DHA intake. Maternal intakes of omega-3 FA are thought to determine a newborn’s DHA status and development of the brain and retinal functions.
Omega 3 and Inflammation
Another interesting area that omega 3 FA play a role in is inflammation. Omega 3 FA have an anti-inflammatory role in decreasing eicosanoids, cytokines and reactive oxygen species, all of which can have a pro-inflammatory effect on the body. Eicosanoids and cytokines are both signaling molecules of the immune system; eicosanoids are produced from omega-6 FA, while cytokines come from proteins. Reactive oxygen species are free radicals that contain oxygen that can wreak havoc on DNA, and even cause cell death. Normal metabolism, along with stress, pollution and poor diet can increase the reactive oxygen species produced in our cells.
So how do omega 3s decrease all these pro-inflammatory molecules? Omega-3 FA can have a direct effect by competing with omega 6 FA on their pathway to becoming eicosanoids, or an indirect effect by altering the expression of inflammatory genes. Some research has shown that the body may also produce anti-inflammatory mediators called resolvins, from the omega 3 fatty acid, EPA.
One observational study found that young adults who took an omega-3 FA supplement during a stressful period had reduced inflammation and anxiety. Supplementation with omega-3 FA was also shown to improve participants’ omega-6 to omega-3 ratio.
Other health benefits of omega 3 fatty acids
Omega-3 FA are being researched in many different areas of health including heart disease, depression and ADHD. Some studies have even shown that a higher consumption of omega-3 FA was associated with a reduced risk of developing breast cancer.
Is the ratio of Omega 3 to Omega 6 fats important?
Typically, we don’t talk about omega 3 fatty acids without also talking about omega 6 fatty acids, which are another polyunsaturated fatty acid. Omega 6 fatty acids are also essential, but in large amounts, may have a pro-inflammatory effect, or even counteract the anti-inflammatory action of omega-3 FA. As a matter of fact, a diet high in omega-6 FA is thought to contribute to increased inflammation in the body. This is where the omega-3 to omega-6 ratio comes in. As previously mentioned above, omega 6 fatty acids compete for the same pathways with omega 3 fatty acids – so more of one can block the conversion of the other.
The western diet tends to range somewhere between 15:1 and 20:1 in omega-6 to omega-3 FA. These high ratios may be linked to cardiovascular disease, cancer and inflammatory and autoimmune diseases. There is disagreement as to the ‘optimal ratio’; however, studies have shown a decrease in total mortality with an improved ratio of 4:1 omega-6 to omega-3 FA.
What does all of this mean? At the end of the day, both omega-3 and omega-6 FA are essential nutrients that must be included in the diet. But if you are currently following a typical Western diet, making some switches to lower the ratio could have some long-term health benefits.
This can be done by switching the type of oil you use from corn to olive oil, and by including some omega-3 fat rich foods that were listed above every single day. Additionally, reducing the intake of meat and soy or seed-based oils, such as safflower and sunflower, can reduce omega-6 FA in your diet.
Do you need an omega 3 supplement?
In my practice, many of my clients take an omega 3 fatty acid supplement…but that doesn’t mean everyone needs one! If you are healthy, and regularly eat omega 3 fat rich foods such as fish or seeds, then a supplement is most likely not necessary to obtain enough omega-3 FA. It’s also worth noting that you do not need to eat fish to get omega 3 fatty acids…seeds will do you just fine!
If you have chronic inflammation such as eczema, arthritis or heart disease, you may benefit from taking a high quality omega 3 supplement in addition to – not in place of – high omega 3 foods in your diet. Women that are pregnant should also consider supplementing with omega-3 FA, to aid in the development of their babies’ brain. If you eat fish, it is very important during pregnancy that you choose low mercury fish to protect your baby’s development.
I typically avoid recommending fish oil supplements, as algal oil is a good, sustainable option for omega 3 FA supplementation. As previously mentioned, EPA and DHA can be obtained from algae. Algal oil is produced from microalgae and is therefore a great plant-based source of EPA and DHA!
There you have it! Everything you need to know about omega-3 FA. If you are unsure whether you need to incorporate more omega-3 FA into your diet, ask a dietitian! We have an amazing team that can help you in determining your needs.
A BIG thank you to Melanie Newman, Year 5 Dietetic Student, who researched and drafted the first draft of this article for me.