Essential Fatty Acids: Omega 3 and Omega 6

Updated Nov 1st, 2021 – Written by Craig Clarke

Although the human body can manufacture most of the fats it needs from other fats, carbohydrates, and protein, there are two groups of fatty acids which cannot be manufactured in the body — omega-3s and omega-6s. We refer to these as “essential fatty acids,” and they help regulate body composition, cell function, immune response, and can also increase overall health and well being. In fact, we can’t survive without crucial roles that omega-3s and omega-6s play in the body, which is why it’s vital to be aware of how much omega 3 & 6 should be achieved each day.

However, before we explore the differences between the two essential fatty acids, let’s establish clear understanding of the underlying purposes of essential fatty acids as a whole.

What Do Essential Fatty Acids Do?

What Do Essential Fatty Acids Do?

Both omega-3 and omega-6 fatty acids are important components of cell membranes and are precursors to many other substances in the body. Altogether, these essential fatty acids help:

  • Transport oxygen throughout our bloodstream
  • Promote cardiovascular health
  • Promote brain development
  • Keep saturated fats mobile
  • Regulate the immune system
  • Reduce blood pressure
  • Maintain fluidity in cell membranes
  • Maintain proper kidney functions
  • Prevent blood cells from clotting
  • Repair and grow cells
  • Prevent various chronic diseases

The general recommendation for minimum essential fatty intake to get these benefits and reduce the risk of chronic disease is 0.6-1.2% of energy (1.6 g/d for men and 1.1 g/d for women aged 19-50).

However, it is much more important to focus on eating each essential fatty acid in the appropriate amounts to avoid any issues that can be caused by eating too many or too few omega-3s or omega-6s. For example, if you eat too few omega-3s and too many omega-6s, you will increase the risk of developing many chronic diseases, chronic inflammation, and mental health disorders. On the other hand, if you eat too many omega-3s and not enough omega-6s, you will increase your risk of developing skin disorders, chronic infections, and an ineffective immune system.

To figure out how to keep both hypothetical scenarios from turning into reality, let’s learn more about each essential fatty acid, starting with the one that most people aren’t getting enough of — Omega-3s.

Omega 3s — Their Purpose and Recommended Intake

Omega 3s — Their Purpose and Recommended Intake

Omega-3 fatty acids are a type of polyunsaturated fat. The term “polyunsaturated” refers to their structure — “poly” means many and “unsaturated” refers to double bonds. Together, they mean that omega-3 fatty acids have many double bonds.

“Omega-3” refers to the position of the last double bond in the fatty acid’s structure, which is three carbon atoms from the “omega” end (tail end) of the molecular chain.

There are many types of omega-3 fats, which differ based on the number of carbon atoms and double bonds they have. Here are the three most common:

  • Eicosapentaenoic acid (EPA) — This 20-carbon fatty acid’s main function is to produce signaling molecules called eicosanoids, which help reduce inflammation. EPA also helps reduce symptoms of depression.
  • Docosahexaenoic acid (DHA) — DHA is a 22-carbon fatty acid that makes up about 8% of our brain weight and is extremely important for healthy brain development and function.
  • Alpha-linolenic acid (ALA) — This 18-carbon fatty acid can be converted into EPA and DHA, although the process is not very efficient. In fact, the conversion is so inefficient that it is not recommended that you try to meet you EPA and DHA needs with ALA consumption. The body mainly uses ALA for energy, but this omega-3 has also been found to reduce the risk of fractures, heart disease, and type 2 diabetes as well.

Other than being a crucial part of human cell membranes, omega-3s (specifically DHA and EPA) have a number of other important functions including:

  • Reducing weight and waist size. Omega-3 fats play a helpful role in weight management and can help reduce waist circumference by decreasing fat storage and stimulating the use of fat for fuel.
  • Improving heart health. Omega-3 fatty acids can increase “good” HDL cholesterol. They can also reduce triglyceride levels, improve blood pressure, and decrease the formation of arterial plaques.
  • Promoting mental health. Taking omega-3s can reduce symptoms of chronic stress, depression, schizophrenia and bipolar disorder.
  • Fighting inflammation and reducing oxidative stress. Omega-3 fats are anti-inflammatory. In other words, they suppress the production of pro-inflammatory compounds and prevent free radical damage in a way that reduces your likelihood of developing various chronic diseases.
  • Preventing dementia. People who eat more fish, which is high in omega-3 fats, tend to have a slower decline in brain function as they age. Omega-3s may also help improve memory in the elderly.
  • Improving insulin function. Studies have shown that omega-3 intake helps decrease insulin resistance, making it an important factor it helping people with type 2 diabetes. Omega-3 supplementation and the ketogenic diet may be a great complementary treatment for these patients.
  • Promoting bone health. People with higher omega-3 intake tend to have better bone mineral density.
  • Decreasing liver fat. Consuming omega-3s can help decrease the amount of fat in your liver and prevent future liver fat accumulation.
  • Supporting infant brain development. Omega-3s are remarkably critical for brain development in babies.
  • Preventing asthma. Omega-3 intake can help reduce symptoms of asthma, especially in early life.

Unfortunately, If you don’t eat fatty fish every week and/or supplement with DHA and EPA, you probably are not meeting your omega-3 needs. This can result in an omega-3 deficiency, which can contribute to chronic diseases like obesity, diabetes, heart disease, as well as mental health disorders like depression and increased aggression.

Although I couldn’t find any universally agreed upon recommendations for omega-3 intake that will allow you to prevent deficiency and reap its benefits, here are some general suggestions:

  • The World Health Organization recommends an omega-3 fatty acid intake of 0.5–2% of energy per day.
  • The American Heart Association suggests that you should be consuming at least two servings of fatty fish per week or 500 mg EPA + DHA per day.
  • People who have heart disease are generally advised to consume approximately 1 gram per day of EPA + DHA preferably from fatty fish or to consider taking EPA + DHA supplements under a physician’s supervision.
  • Patients who need to lower their triglyceride levels would benefit from taking 2–4 grams per day of EPA + DHA supplements under a physician’s care.

How to Meet Your Omega-3 Needs

How to Meet Your Omega-3 Needs

Arguably the healthiest way to meet your omega-3 needs is by consuming fatty fish. However, you can also obtain omega-3s from omega-3 supplements, shellfish, algal oil, nuts, and seeds. (Keep in mind that nuts and seeds only contain ALA, which isn’t converted into EPA and DHA efficiently.)

Here is a list of keto-friendly foods that contain the most omega-3s:

  • Salmon: 3 ounces has ~1.8 grams of EPA and DHA
  • Sardines: 3 ounces has ~1.2 grams of EPA and DHA
  • Mackerel: 3 ounces has ~1 gram of EPA and DHA
  • Rainbow Trout: 3 ounces has ~0.8 grams of EPA and DHA
  • Sea Bass: 3 ounces has ~0.7 grams of EPA and DHA
  • Chia seeds: 1 ounce has 5 grams of ALA
  • Walnuts: 1 ounce has 2.5 grams of ALA
  • Flaxseeds: 1 ounce has 2.3 grams of ALA

By using this chart and the recommended omega-3 intakes from the previous section, you will be able to figure out how you can meet your needs every day.

If you don’t eat the foods on this list very often, there is no need worry. You can always take a supplement.

However, don’t just buy and take any random omega-3 supplement. There a couple of things that you must be aware of first:

  • Only purchase supplements that have DHA and EPA. ALA supplementation is not necessary.
  • Fish oil, krill oil, cod liver oil, and algal oil are the most popular DHA and EPA supplements, and they all seem to have similar bioavailability. Some research suggests that krill oil is a bit more bioavailable than fish oil.
  • Omega-3s can be found in supplements as re-esterified triglycerides, natural triglycerides, free fatty acids, and ethyl esters. Ethyl esters seem to have a somewhat lower bioavailability than the others, but each form will significantly increase plasma EPA and DHA levels.
  • The FDA suggests not to exceed 3,000 mg of EPA and DHA per day, as this dosage can cause blood thinning and excessive bleeding in some people.
  • Make sure you are not consuming too much vitamin A with your omega-3 supplements. Cod liver oil, for example, typically contains high levels of vitamin A, which can be potentially toxic for some people.
  • Select a supplement that comes with antioxidants (like vitamin E or rosemary extract), is processed at low temperatures, and has the highest omega-3 content (more than 0.3 grams of EPA + DHA per serving is good).
  • Store your supplement at a temperature that is below 39 degrees Fahrenheit. (The shelf life of omega-3s is only about six months when stored at ~39 degrees Fahrenheit. When it is stored at higher temperatures and exposed to excess light, the omega-3s tend to oxidize more rapidly.)

With the help of fatty fish and omega-3 supplements, you will be able to meet your omega-3 needs without a problem. Fortunately, this is the only essential fat that you may need to supplement with. This is because most of us are already getting more than enough omega-6s in our diet.

Omega 6s — Their Purpose and Recommended Intake

Omega 6s — Their Purpose and Recommended Intake

Like omega-3 fatty acids, omega-6 fatty acids are polyunsaturated fatty acids as well.

There are two main differences between these two fatty acids: (1) The last double bond is in a different place, and (2) they both serve distinct purposes in the body.

For example, omega-6s:

  • Help regulate immune system function by
  • Provoking inflammation at the right times.
  • Improve blood pressure levels, blood clotting capacity, and brain function

Furthermore, two particular omega-6 fatty acids called Gamma-linolenic acid (GLA) and Conjugated linoleic acid (CLA) have been found to have even more impressive benefits, such as:

  • Reduced rheumatoid arthritis symptoms (GLA)
  • Decreased inflammation levels (GLA)
  • Improved hormonal balance (GLA)
  • Reduced body fat mass (CLA)

However, CLA and GLA aren’t the most common omega-6s — the most common is linoleic acid (LA). LA is either burned as energy or converted into longer omega-6 fats such as arachidonic acid (ARA). This is worth knowing because ARA is used to produce eicosanoids (signaling molecules) that are more pro-inflammatory. These pro-inflammatory eicosanoids are important chemicals in the immune system, but when too many of them are produced, they can increase the incidence of inflammation and inflammatory disease.

Unfortunately, the Western diet tends to promote the production of these pro-inflammatory eicosanoids so much that it is one of the reasons why heart disease rates have been climbing in western cultures. For this reason, it is best for most people to dial down their omega-6 intake and increase their omega-3 consumption (by using the suggestions from the previous section of this article). By doing so, you will be able to avoid essential fatty acid deficiency and optimize your omega-6 to omega-3 ratio.

How to Meet Your Omega-6 Needs

Omega-6 fats are found in large amounts in refined vegetable oils and foods cooked in vegetable oils. While you are on the keto diet, you will be getting most of your omega-6s from nuts, seeds, and animal products.

According to the Food and Nutrition Board of the US Institute of Medicine, the adequate intake of omega-6s per day is 17 grams for men and 12 grams for women, for adults from 19–50 years old.

Here is a list of some keto-friendly food products with high omega-6 content that you can use to meet these needs:

  • Soybean oil: 50 grams per 100 grams
  • Corn oil: 49 grams per 100 grams
  • Mayonnaise: 39 grams per 100 grams
  • Walnuts: ~10.6 grams per ounce
  • Sunflower seeds: ~9.6 grams per ounce
  • Bacon: ~4.8 grams in every 3 ounces
  • Peanuts: ~4.1 grams per ounce
  • Almonds: ~3.8 grams per ounce
  • Chicken thighs (with skin): ~3.2 grams in every 3 ounces
  • Eggs: ~0.6 grams in every whole egg
  • Butter: ~0.3 grams per tablespoon

How to Meet Your Omega-6 Needs

As you can see, it is almost effortless to get more than enough omega-6s through your diet — even if you are on the keto diet.  In other words, you most likely will never have to supplement with omega 6s.

How to Optimize Your Health with Essential Fatty Acid Intake

How to Optimize Your Health with Essential Fatty Acid Intake

A balance between adequate omega-3 and omega-6 consumption is mandatory for optimal health. The typically recommended balance to have is a 2 to 1 ratio of Omega-6s to Omega-3s, but anywhere between 1:1 and 4:1 is good.

The typical Western diet will be between 20:1 and 40:1, to give you an idea of how many Omega-6’s we actually consume. This contributes to inflammation and oxidation in our bodies, which also leads to a number of diseases and mental disorders.

To improve your omega-6 to omega-3 ratio so that these issues don’t occur, you must do two things:

  • Consume enough omega 3s (most of them coming from DHA and EPA).
  • Cut out high omega-6 foods from your diet.

You already know how to ensure that you have adequate DHA and EPA intake, so let’s learn about how you can decrease your omega-6 consumption while you are on the keto diet (and pretty much every other diet).

Here are a few techniques to reduce your omega-6 intake while increasing your omega-3 intake:

  • Stop using cooking oils that are high in omega-6s (e.g., vegetable oil, soybean oil, and corn oil).
  • Eat more fatty fish and/or supplement with a DHA and EPA supplement.
  • Eat grass-fed meats and dairy and pasture raised eggs and pork.
  • Limit your almond, almond flour, sunflower seed, and walnut consumption.
  • Eliminate all processed foods from your diet.

By following these simple strategies to increase your omega-3 intake and decrease your omega-6 consumption, researchers have found that you will alter the inner environment of your cells and tissues and reduce your risk of heart disease and other inflammatory conditions.

So Unstable — The Bad Side of Omega 3s and Omega 6s

So Unstable — The Bad Side of Omega 3s and Omega 6s

There is still one caveat regarding both essential fatty acids that you must be aware of — They oxidize easily. Once your fats are oxidized, they become virtually useless and harmful to your body. In other words, if you are consuming high omega-6 oil or DHA and EPA supplements that have been exposed a lot of heat, oxygen, and/or light, then you will not get the benefits from eating those fats. All you will get is a concoction of toxic compounds.

The general rule of thumb for all fats is that polyunsaturated fats are the least stable. This means you should avoid all polyunsaturated fats (including omega-3s and omega-6s) that have been exposed to high heat, a lot of light, and/or oxygen.

When it comes to cooking, use oils that have a high smoke point:

  • Tallow
  • Lard
  • Avacado Oil
  • Coconut Oil
  • Palm Oil
  • Olive Oil
  • Ghee

You will find that many of these oils do contain some polyunsaturated fatty acids, but they also contain antioxidants and/or other stable fats that keep them from oxidizing to some degree.

When topping your food, go with oils that are rich in polyunsaturated fats and have a low smoke point:

  • Hemp Seed Oil
  • Flax Oil
  • Walnut Oil
  • Grape Seed Oil

However, feel free to use olive oil, avocado oil, and/or MCT oil instead because you will probably be meeting your essential fatty acid needs with other keto foods.

Fatty Acid Rankings for The Most Common Fat Sources

Here are some rankings of the most common fats/oils. Remember, you want to cook with fats that are lower in polyunsaturated fats (and higher in antioxidants), and top your food with things high in polyunsaturated fats (if you need to meet your essential fatty acid needs). The higher the content of polyunsaturated fat, the easier it will oxidize with heat. Oxidization is bad.

To optimize your health, you will want to stay away from oils that have a very high ratio of omega-6s to omega-3s like safflower oil, sunflower oil, corn oil, and sesame oil.

Type of Fat Saturated Fats Monounsaturated Fat Polyunsaturated Fat Omega-3 % Omega-6:Omega-3
Coconut Oil 92 6 2 0 0
Ghee 65 32 2 0 0
Butter 51 21 3 0.5 4:1
Macadamia Oil 13 84 4 2 1:1
Tallow 50 42 4 0 0
Palm Oil 50 39 9 1 9:1
Hazelnut Oil 7 78 10 0 0
Lard 40 45 11 0 0
EV Olive Oil 14 73 11 0 0
Avocado Oil 12 70 13 1 12:1
Cod Liver Oil 23 47 23 19 0.2:1
Peanut Oil 18 47 29 0 34:1
Canola Oil 7 54 37 10 2.6:1
Sesame Oil 17 42 45 0 45:1
Walnut Oil 9 23 63 10 5.3:1
Flax Oil 9 20 66 53 0.2:1
Grapeseed Oil 12 17 71 0.8 75:1
Safflower Oil 12 13 75 0.6 78:1

If you are unsure about the exact temperature that these fats/oils can withstand, do a quick search for their smoke points. The higher the smoke point, the more stable that fat/oil is when exposed to heat.

Once your fat/oil is exposed to the temperatures above what is indicated by the smoke point, your fat/oil will start to oxidize and become almost entirely useless and harmful to your body.

Putting It All Together — Essential Fatty Acids, Your Health, and Keto Dieting

Omega-3s and omega-6s are known as essential fatty acids because we have no way of making them ourselves. As a result, we must consume foods and/or supplements that help us meet our need for these essential fats and reap their benefits.

In general, the recommended intakes for omega 3s and omega 6s are as follows:

  • 17 grams for men and 12 grams for women of Omega 6s per day
  • 0.5–2% of energy in omega 3s  per day with at least 500 mg coming from EPA + DHA

Most people are consuming too many omega-6s and not enough omega-3s. This increases the risk of various inflammatory diseases and mental disorders, so it is best to optimize our intake of these essential fatty acids.

To do this, try implementing these strategies:

  • Stop using cooking oils that are high in omega-6s (e.g., vegetable oil, soybean oil, and corn oil).
  • Eat more fatty fish and/or supplement with a DHA and EPA supplement.
  • Eat grass-fed meats and dairy and pasture raised eggs and pork.
  • Limit your almond, almond flour, sunflower seed, and walnut consumption.
  • Eliminate all processed foods from your diet.

Also, make sure you aren’t exposing your polyunsaturated fats to high temperatures. Both omega 3s and omega 6s are highly unstable so make sure your omega-3 supplements and high polyunsaturated fat oils are stored at cool temperatures and never cooked.

For cooking, you should stick with these fats/oils:

  • Tallow
  • Lard
  • Avacado Oil
  • Coconut Oil
  • Palm Oil
  • Olive Oil
  • Ghee

By following the recommendations throughout this article, you will be able to meet your essential fatty acid needs and experience all of their benefits in a keto-friendly way. If you’d like to learn more about the fats featured in this article, check out our articles on omega-3s and omega-6s. For an overview of each type of fat that you will be eating on keto, check out our post on the importance of fats.