Omega-3 and omega-6 fats are getting more and more hype in the nutrition arena, and for good reason. These fatty acids influence many health factors in the body, from inflammation to cardiovascular disease to brain neurodegenerative diseases - which are actually many of the reasons people use the ketogenic diet. If you're really interested in improving your health on the ketogenic diet, or any diet for that matter, understanding omega-3 and omega-6 fats will be vital.
What are Omega-6 and Omega-3 Fatty Acids?
Omega-6 and omega-3 fats are types of polyunsaturated fatty acids, also known as PUFA's. PUFA's in general have been incorporated under a "good fat" label in the food industry; but that's a wrong assumption to make. While omega-3 polyunsaturated fats have exceptional health benefits, omega-6 fatty acids can be detrimental in large quantities, and here's why...
Omega-6 fatty acids compete with omega-3 fatty acids in the body, therefore lessening the effects of omega-3's. Therefore, it's not only important to incorporate omega-3's into your diet, but you need to have an awareness of the ratio of omega-6 to omega-3 fatty acids you are consuming.
The omega-6/omega-3 ratio has health effects on inflammation, weight loss and brain function. If you're on the ketogenic diet for any of these reasons, then eating the correct ratio will be important for your health goals.
There are two main reasons the ratio is important:
- EPA, an omega-3, directly competes with AA, an omega-6, to either reduce (EPA) or promote (AA) inflammatory mediators in the body.
- The amount of omega-6 fatty acids in the body directly effects the amount of ALA (most common omega-3) that can be converted to DHA and EPA. While ALA is more abundant and easier to get from dietary sources, EPA and DHA can be difficult to consume in enough quantities without supplementation. EPA and DHA have been shown to have the most significant health benefits out of all the omega-3 fats.
The typical American diet has an omega-6/omega-3 ratio between 17:1 and 22:1. The ideal ratio of omega-6:omega-3 in recent studies has been found to be between 1:1 and 2:1. That's a huge difference between what people are typically eating!
Omega-6 fats creep into people's diet through fried foods, fast foods and packaged foods containing soybean oil. peanut oil and even peanut products. Even a few servings of some "healthy" keto foods like almonds contain enough omega-6 fatty acids to increase the omega-6/omega-3 ratio to an unhealthy number.
A high ratio of omega-6 to omega-3 fatty acids causes increased inflammation in the body which is associated with atherosclerosis, obesity, and diabetes. A high ratio can also cause inflammation in the brain which is associated with Alzheimer's and other neurodegenerative diseases.
Although up to now we've been talking about omega-3's in general, don't be fooled into thinking that the individual omega-3 fatty acids don't each have a different effect on health. Each omega-3 fatty acid is important to the body in its own way.
Types of Omega-3's
There are 4 main types of omega-3 fatty acids: ALA, DHA, EPA and DPA. ALA, DHA and EPA are more common and can be found readily in fish oil supplements and in food. The health research on DHA and EPA is abundant. Research on DPA is limited and while it is very positive, we will not discuss DPA further.
ALA Omega-3 Fatty Acid
The most commonly occurring omega-3 is ALA, also known as alpha-linolenic acid. ALA is an essential omega-3 fatty acid, meaning you must consume it in your foods or supplements because your body cannot make it.
Increasing studies are coming out with benefits of alpha-linolenic acid. ALA has been noted in some studies to reduce inflammation by way of reductions in C-reactive protein and pro-inflammatory cytokines. This has been associated with reduced risk of cardiovascular disease. ALA has also been associated with antioxidant function and insulin sensitivity. While these benefits are great, the health impact of ALA does not come close to those of EPA and DHA.
Alpha-linolenic acid is found easily in some popular foods. Walnuts contain a decent amount, while flaxseeds and chia seeds are very high in ALA. In only a tablespoon you can get in the range of 2000 mg of ALA. Since chia seeds and flaxseeds can be easily found in grocery stores and are decently affordable, getting ALA in your diet is pretty easy.
DHA and EPA Omega-3 Fatty Acids
DHA, also called docosahexaenoic acid, and EPA, eicosapentaenoic acid, are not as prevalent in foods or easy to get as ALA. This is a problem because DHA and EPA have been shown to have the greatest positive impacts on health out of the omega-3's.
Docosahexaenoic acid is the most prevalent omega-3 in the brain. In fact, it is 300 times more prevalent than eicosapentaenoic acid. It has been noted to be most helpful in conditions of the brain like Alzheimer's disease. Increased DHA has neuro-protective and anti-inflammatory benefits.[i]
EPA can be anti-inflammatory as well, but for cells throughout the body. EPA is also good for the brain, but in a different way than DHA: it is good for parts of the brain that deal with mood disorders like depression.
In addition, both EPA and DHA have been shown to help improve insulin resistance, cardiovascular disease risk, and even breast and prostate cancer risks.
So how do you get DHA and EPA?
Both DHA and EPA are primarily found in fish and algae food products like seaweed. Fatty fish like salmon, tuna and trout contain high amounts of DHA and EPA.
ALA is a precursor to EPA and DHA, meaning that it can form EPA and DHA in the body. The only problem is that only a very small percentage of the ALA can be transformed to EPA and DHA. In fact, the International Society for the Study of Fatty Acids and Lipids (ISSFAL) recently stated the conversion of ALA to DHA in adults is considerably lower than 1%.[ii] The amount of EPA converted actually depends on the amount of omega-6 vs omega-3 in the body, but it can be upwards of 10% of ALA consumed.[iii]
How much Omega-3 should someone on the keto diet get?
The FDA has set a recommended daily intake value for omega-3's of no more than 3 grams (3,000 mg) per day. However, they did not specify how much of each kind of omega-3, nor do they take into account high fat diets like the ketogenic diet.
Someone on the ketogenic diet who eats high amounts of almonds or pecans to meet their fat macros may consume more omega-6 than a standard American. If you are on the keto diet, you may need to go above the FDA's recommended amount of omega-3's. Remember, it is the ratio of omega-6 to omega-3 fats that's important.[iv]
We've done some calculations, and if you're eating only a few servings of pecans, peanuts or almonds during the day and not eating any omega-3 foods or taking any supplements, then your ratio could be anywhere from 12:1-70-1! Yep, only a few servings of peanuts will take your omega-6:omega-3 ratio up to the 70's. That's way above the average of the standard American!
The table below shows our quick calculations on possible omega-6/omega-3 ratios on the keto diet. For these calculations we will assume you eat mostly coconut oil, butter and avocado as your fats - which have minimal amounts of omega-6 or 3, so therefore minimal impact on your ratio.
|No Omega-3 Supplement||1000 mg Omega-3||2000 mg Omega-3||3000 mg Omega-3|
|1 serving peanuts||29:1||5:1||2.8:1||1.9:1|
|1 serving almonds||26:1||4.5:1||2.5:1||1.7:1|
|2 total serving nuts, 1 peanuts + 1 almonds||45:1||7.9:1||4.3:1||3.0:1|
So in this theoretical situation, eating only 1 serving of peanuts per day requires 3,000 mg of omega-3 to get to the recommended ratio!
If you are eating any high omega-6 foods we recommend either limiting your in-take or figuring from the above table the proper amount of omega-3 you need to counter your omega-6. As you can see from our table, each serving of peanuts or almonds requires about 3,000 mg of omega-3 to get to the recommended ratio of between 1:1-2:1.*
How much of ALA, DHA and EPA do you need?
That all comes down to a few key points. Remember when we said that...
- EPA competes with AA - and they have direct effects on inflammation?
- There's almost 300 times more DHA than EPA in the brain?
- At most around 10% of ALA consumed is made into EPA, while almost no DHA is made
- EPA and DHA have significantly more positive impacts on a range of health factors than ALA
EPA and DHA will be the most important omega-3's to get in your diet.
It has been shown in studies that the best way to increase EPA and DHA in the body is to supplement (or eat food) with that particular omega-3. We recommend that most of your omega-3 consumption is made up of these. In order to do this, you should be eating fatty fish like salmon several times a week, or taking an omega-3 supplement, fish oil or krill oil supplement with high amounts of EPA and DHA.
Keep in mind there are several kinds of salmon with differing amounts of omega-3's. Pink salmon that is farmed or wild will not contain even close to the amount of omega-3's as King salmon (aka Chinook salmon); however, King salmon can be up to 3x the price of pink salmon. Unless you like the flavor of salmon (try one of our keto salmon recipes), we recommend taking omega-3 supplements to get proper amounts of EPA and DHA. It can end up being very expensive to get enough DHA and EPA from actual food.
And don't worry that supplements will be a waste: studies suggest that whether you are consuming actual high omega-3 fatty fish or fish oil supplements, both are equally effective at enriching omega-3's in the body.[v]
Remember, just because a product says omega-3 on the front, does not mean it contains any DHA or EPA! It could be entirely made up of ALA. While ALA is not bad, don't go spending a lot of money on fish oil supplements containing only ALA when you should be spending that money on EPA and DHA.
[i] Breanne M Anderson and David WL Ma* Are all n-3 polyunsaturated fatty acids created equal? Lipids in Health and Disease 2009, 8:33
[ii] alpha-Linolenic acid supplementation and conversion to n-3 long-chain polyunsaturated fatty acids in humans.
Brenna JT1, Salem N Jr, Sinclair AJ, Cunnane SC; International Society for the Study of Fatty Acids and Lipids, ISSFAL.
[iii] Kerstin Harnack1, Gaby Andersen1 and Veronika Somoza. Quantitation of alpha-linolenic acid elongation to eicosapentaenoic and docosahexaenoic acid as affected by the ratio of n6/n3 fatty acids. Nutrition & Metabolism 2009, 6:8
[iv] Artemis P. Simopoulos. An Increase in the Omega-6/Omega-3 Fatty Acid Ratio Increases the Risk for Obesity.
[v] William S Harris, James V Pottala, Scott A Sands, and Philip G Jones. Comparison of the effects of fish and fish-oil capsules on the n–3 fatty acid content of blood cells and plasma phospholipids. Am J Clin Nutr 2007;86:1621–5.