Thursday, September 8, 2011

Omega-6 vs. omega-3 fatty acids

Everyone who has written one of the famous paleo books or is interested in nutrition and health otherwise, has probably heard about omega-3 and omega-6 fatty acids. So what is the difference and what influence do they have on your health?

By Ben Mills (Own work) [Public domain],
 via Wikimedia Commons
Chemical definition
Omega-3 and omega-6 fatty acids both belong to the group of unsaturated fatty acids. Fatty acids are composed out of variably long chains of hydrocarbon molecules and a carboxylic acid (-COOH). Unsaturated fatty acids have at least one double bond between to carbonate molecules in the chain. The numbers 3 and 6 define the position of this doble bond in the chain. Both omega-3 and omega-6 fatty acids are essential, which means that they cannot be produced by your own body and therefore need to be taken up over food.

Omega-3 fatty acids
There are 3 known omega-3 fatty acids. Docosahexaenoic acid (DHA), eicosapentaenoic acis (EPA) and alpha-linolenic acis (ALA). DHA is a part of the cell membranes of nerve cells and is therefore mainly found in the brain and the retina. EPA is the chemical precursor for producing eicosanoids. Eicosanoids are signaling molecules which control may bodily systems like inflammation and act as messenger in the central nervous system. ALA can be converted over EPA to DHA, but the efficiency of this process is only 5%.

Omega-6 fatty acids
To this date we know 11 different omega-6 fatty acids, the most prominent being linoleic acid. Linoleic acid is part of the human skin and involved in producing components which regulate inflammation in the body.

Omega-6 to Omega-3 ratio
Omega-6 and omega-3 fatty acids on their own are no problem for the human body. In fact the human body needs both of them for the mentioned functions. The critical factor for health is the ratio between the two fatty acids. Natural folks had a ratio between 1:1 and 2:1 (n-6:n-3). In our modern western culture this ratio went up to 20:1. And that's where the problem lies. While the eicosanoids produced from the omega-3 fatty acid EPA lower inflammation, there are eicosanoids produced out of omega-6 fatty acids which boost inflammation. Omega-6 fatty acids for example produce prostaglandins which are associated with pain, blood clotting and inflammation. As long as omega-6 and omega-3 fatty acids are in balance, they also equilibrate inflammation processes in the body. If we eat food with too many omega-6 fatty acids, we get sick.

By Bill Branson (photographer) (National Cancer Institute: page, image)
[Public domain], via Wikimedia Commons

Increased occurence of omega-6 fatty acids can be found in vegetable oils and processed food but also in nuts and convetional, grain-fed meat. It's best to avoid vegetable oils and processed foods completely. Nuts do also have some positive nutritional values and should be consumed in moderation. If possible, it's best to only eat grass-fed meat because it has much less omega-6 fatty acids. Since this is not possible for everyone, one can supplement with fish oil to get more omega-3 fatty acids. They are supposed to balance the overintake in omega-6 fatty acids which happens when you eat mostly onventional meat. A reasonable amount, which only applies if your generally healthy and fit, are 1-3g per day. Fish oil is mainly made out of EPA and DHA and can be bought in liquid form or as capsules. I myself do supplement with 3 tea spoons of this fish oil every day. How do you keep your fatty acid ratio in balance? Do you just eat gras-fed meat or do you supplement?


  1. Good article. I suggest you learn what Ray Peat has to say about the so-called essential fatty acids.

  2. Thanks for the reading tip. I'm always happy to further educate myself.

  3. Hi Steffi, I did a post earlier this year and collated the amounts of omega 6 and 3 in many fats, oils, nuts, meats and seafoods, and made up charts of each, so I could make better choices. Cron-o-meter is a programme that you can enter your food in and it will tell you if your diet is balanced. There is a link in my post here: