The importance of the Omega 3 / Omega 6 ratio in nutrition

Today we recommend an Omega 3/Omega 6 ratio of 1/5, i.e. 1 molecule of Omega 3 for 5 molecules of Omega 6. Today in France, current epidemiological data are still very far from official recommendations.

• The average ratio is around 1/10.
• Barely 50% of ANC covered for omega 3.
• Only 1.2% of the adult population meets the recommendations for ALA (vegetable Omega 3);
• 14.6% for DHA and 7.8% for EPA (animal Omega 3).

Since the 1960s, our Western diet (that of humans and that of the animals on which they feed) has been significantly enriched in sources of omega 6 and depleted in omega 3. Here are some key figures to understand the evolution of this balance throughout the history of humanity:

• From 1/1 to 1/2 (Omega 3/Omega 6) in Cro-Magnon Man
• Around 1/5 in the Neolithic with the development of agriculture
• Increasing with the industrial era and the agri-food industry to 1/15 in Europe today (1/17 in the USA) and 1/30 in certain cases.

Why this preference in our modern diet for Omega 6? This is particularly linked to the fact that Omega 6 goes rancid less than Omega 3. The food industry has therefore gotten into the habit of using oils rich in Omega 6 in order to favor the preservation and taste of food. The best example is Sunflower oil, very stable, with a mild taste, very rich in Omega 6.

Omega-3 and omega-6 compete in our body. It is therefore necessary to select oils that are both rich in omega-3 but relatively low in omega-6, which is the case for rapeseed (ratio around 4/1): 2 tablespoons of rapeseed oil per day covers the ANC in ALA.

Like olive oil, rapeseed contains a large quantity of omega-9 which interferes with the metabolism of omega-6. Michel de Lorgeril therefore advises combining rapeseed and olive oils on a daily basis, the latter being, moreover, rich in protective antioxidants.

If you are unable to change your daily habits sufficiently (seasonings, cooking oils, etc.), you can also choose to ingest a teaspoon per day of these vegetable oils particularly rich in Omega 3: Flax, Camelina, Perilla or Hemp. These vegetable oils contain up to 50-60% Omega 3! 

It is of course possible to increase your intake of plant Omega 3 (ALA) in forms other than with pure vegetable oils. This is particularly true with oilseeds and fruits.

• nuts provide an excellent intake of ALA: six or seven nuts per day cover our needs. They also provide other valuable nutrients, such as phosphorus or magnesium.

• squash and pumpkin seeds, flax, hemp, chia, soy also contain a lot of them.

• details regarding flax seeds (a heaped tablespoon per day is enough to cover the daily omega-3 needs): before eating them, they must be soaked, crushed, crushed, ground. Chew them well if you don't have time... Otherwise, they will be evacuated intact, because the stomach cannot dissolve the seed coat, whether it is brown or blond (even if the blond is less thick) . Grinding at the last moment allows you to only use what you really need, as ground seeds do not keep long (a few days in the refrigerator). On the contrary, intact seeds keep very well and for a very long time, in a dry and cool place.

To a lesser extent, you can find ALA in vegetables like purslane, pumpkin, chard, cabbage.

As we explained above, the body cannot be satisfied with a single intake of ALA (plant), there must also be intakes of EPA and DHA (animal). You can find animal Omega 3 in quantity in the following foods:

• small fatty fish (sardines, mackerel, herring, anchovies): 1 to 2 times per week to cover your EPA and DHA needs. This is by far the most "reliable" method.

• the salmon, but ! If it's a farmed salmon, it's a safe bet that its own diet is very unbalanced in omega 3/6. If it is wild salmon, you may more and more often be faced with concerns about heavy metal toxicity... Trout is therefore often favored over salmon.

• eggs, milk, meat. Once again, an important nuance is necessary. If you are not careful about the diet of the animals from which these products are produced, you are almost certain to be dealing with a very poor level of Omega 3/6. No more than humans, animals are not capable of producing Omega 3: if you don't give it to them, they won't give it to you!

Animal nutrition is therefore very important to restore the right balance because a diet rich in omega 6 based on sunflower, soya and corn is then found in everyday consumer products such as meat, eggs or milk. Dare Plants rich in Omega 3, such as rapeseed, alfalfa and linseed, have been reintroduced into the diet of certain livestock to rebalance this situation.

This is the case, for example, for products Blue-white-heart. This is a label that you can find on many mass-market products. For example for eggs: hens whose diet is naturally rich or enriched in sources of omega 3 (flax-based supplementation) produce eggs which contain on average fifteen times more omega 3 than a standard egg.

With the preceding article, you normally have everything you need to understand why the Omega 3/6 balance is important. However, you may be frustrated to have covered the mechanisms of transformation of plant Omegas into Omegas usable by the body, as well as the impact of the latter on inflammation. That’s what we’re going to dig into here.

Plant Omega 3 (Alpha-Linolenic Acid = ALA) and plant Omega 6 (Linoleic Acid = AL) are therefore polyunsaturated fatty acids with the following characteristics:

• a size of 18 carbons;
• 2 double bonds for Omega 6 and 3 for Omega 3.

When they are ingested by a man or an animal, they will pass into the expert hands of 2 successive enzymes, called delta-6-desaturase and delta-5-desaturase, which go both extend the size of the chain, and add double bonds. Once the work of these 2 enzymes is completed: 

• ALA (omega 3) gave birth to the EPA, a so-called “animal” omega 3, of length 20 and having 5 double bonds;
• LA (omega 6) gave birth at the AA, Arachidonic Acid, of length 20 and having 4 double bonds.

It is important to emphasize this: to carry out this transformation, the two omegas therefore need the same enzymes! Hence the competition…

But the story is not over for Omega 3 since part of the EPA will once again be processed by the delta-6-desaturase enzyme (still in high demand), in order to form DHA, Omega 3 of length 22 having 6 double bonds.

If we summarize, at the beginning of the course we have the ALA and the AL. At the end of the process, if everything has gone well and your enzymes have not been overloaded (by excess sunflower oil), we have AA (Omega 6), EPA (Omega 3) and DHA (Omega 3). It is in this form that Omegas will be able to play their role in the inflammatory process., and we'll see how. 

You now understand better why a simple intake of plant-based Omega 3 can sometimes be of no use, and that it is important:

• to also bring animal Omegas to your diet: your body must in fact implement many means to change ALA into DHA, means which it does not necessarily have at its disposal (time, limited yield of enzymes, energy, etc.).
• to reduce Omega 6 intake.

Once your body, through desaturase enzymes, has lengthened your Omega 3 and 6, these new fatty acids will be able to be oxidized by other enzymes, oxidoreductases with the sweet name of "cyclo-oxygenases". These enzymes will, via a complex process (several steps, several different enzymes), produce metabolites directly used by our body in inflammatory processes.

Arachidonic Acid, or AA, Omega 6, will therefore give rise to metabolites of 3 types:

• Prostaglandins;
• Leukotrienes;
• Lipoxins.

Eicosapentaenoic acid (EPA), Omega 3, will give rise to metabolites called: Resolvins.

Docosahexaenoic acid (dha), Omega 3, will give rise to metabolites of 3 types:

• Resolvines (also);
• Protectins;
• Maresines.

We are not going to go into the precise processes of action of each of these metabolites, but here is the role of each of these metabolites in the inflammatory process.

Roles and specificities of chemical mediators from omega 6:

• When necessary, the Prostaglandins (type 2) and Leukotrienes, both “cascade” products of your Omega 6, will act directly in the acute inflammatory process. They contribute to the development of several inflammatory manifestations, particularly at the cardiovascular level (e.g. vasodilation, coagulation, blood pressure), bronchial (link with asthma) or pain, etc.

• THE Lipoxins on the contrary are pro-resolvers of inflammation, which induce the resolution phase of inflammation. They inhibit the migration of neutrophils towards the site of the inflammatory reaction and the production of inflammatory mediators. Their action does not, however, allow the resolution of the inflammation, but they “start the process”.

Roles and specificities of chemical mediators from omega 3: 

Triggered by lipoxins at the end of the acute phase of inflammation, resolvins and protectins induce the resorption of the causes and mediators of inflammation, the replacement of damaged cells, and the restoration of normal functioning.

If omega 3 is not present in sufficient quantities, the inflammation cannot be completely resolved. There can therefore be theestablishment of chronic inflammation or so-called “low-grade” inflammation, latent, diffuse and deleterious. For example, when it comes to inflammation caused by an injury, fibrosis may develop instead of healing.