The cell membrane forms a “fluid mosaic” in which each component can move more or less freely. This membrane fluidity is the basis of the cellular balance, including exchanges between the inside and the outside of the cell.
A rigid membrane rich in saturated fatty acids causes little exchange. A flexible membrane rich in polyunsaturated fatty acids facilitates exchanges between the inside and the outside of the cell.
- SFA saturated fatty acids (butyric acid, myristic acid, Palmitic acid, stearic acid,…) are made largely by butter, cold cuts, cheese… the animal fat.
- Monounsaturated fatty acids MUFAs (oleic acid…) are brought by the olive oils, rapeseed, peanut, avocado… but also duck fat.
- Polyunsaturated Fatty acids PUFAs (omega 6: Linolenic acid, acid γ-linolenic, arachidonic acid, omega 3: α-linolenic acid, acid meiosis EPA, DHA Docosahexaenoic acid) are brought by the oils of sunflower, corn, grape seed… Rapeseed, soy, hemp, flax… for the omega 3. Regarding the long chained PUFA, EPA and DHA, the main sources are fish from cold seas (herring, mackerel, sardines, anchovies…).
Steps of transformation of the omega 3 and 6 series fatty acids
- Line Omega 6 : Linoleique acid = > Acid γ-linolenic = > Arachidonic acid.
- Line Omega 3 : Acid α-linolenic = > Meiosis EPA acid = > DHA Docosahexaenoic acid.
Linoleic and α-linolenic acids are called “essential” because the body of the animal (including human) does not synthesize them. So they must be provided by the diet. An imbalance of omega 6 (proinflammatory activity) / omega 3 (anti-inflammatory activity) with too much omega 6 regarding omega 3 encourages inflammation phenomena, aggregation and vasoconstriction with risk for our lungs (asthma…), cardiovascular (angina, myocardial infarction…), articular (arthritis…), musculotendinous (tendinitis…) …
For example in the cardiovascular level, EPA acid has an action on the reduction of triglycerides (Hyperlipidemia), on the Fibrinogen rate of the blood and consequently, on the platelet aggregation and the risk of heart attack.
DHA acid’s action is located at the level of the development of the brain. It has an impact on the retina, the integrity of brain functions, the activity of the adrenal glands, the formation of sperm… This last fatty acid represents 95% of the omega 3 brain fatty acids, which is why it is called cervonic acid.
The effects of omega 3
The Omega 3, as the other PUFAs, are essential to cell membranes constituents and provide them with fluidity and stability. It is the keystone of the cellular mechanism, of the organs (heart, liver, kidney, brain…) and consequently of the entire body. The loss of membrane fluidity promotes the occurrence of pathology (= disease). They improve the nervous balance (memory, concentration,…), help to reduce stress, promoting optimism and serenity, decrease the lipemia (cholesterol, triglycerides), platelet aggregation…
Omega 3 are indicated in the following cases:
- Dermatology (eczema, itch, psoriasis…),
- Pneumology (asthma, particularly in children…),
- Gastroenterology (ulcer colitis, Crohn’s disease),
- Gynecology (dysmenorrheas,…).
- Rheumatology (inflammatory field, joint problems,…),
- Internal medicine (migraine, diabetes, viral diseases…).
If the needs are not covered, there are direct consequences at various levels of the bodiy, and especially in the brain.
The loss of membrane fluidity at the level of the synapses promote synaptic anxiety and ultimately neurotransmission abnormalities which creates risks of depression, dementia, behaviour disorders, violence… Note: alcohol, nicotine or anxiolytics, which dissipate the stress and anxieties, have the property of temporarily thin cell membranes.
The loss of membrane fluidity at the level of myocardial cells promote the anomalies of the ionic exchanges and depolarization, discrepancy of deformability (systole-diastole), cardiomyopathy, HTA, high cholesterol…
Atherosclerosis : loss of membrane fluidity at the level of cells stiffens the membrane which cannot absorb no more the LDL-cholesterol circulating (at the blood level) for lack of place. This phenomenon causes atherogenesis and hyperagregability.
The loss of membrane fluidity at the level of the bone cells (osteoblast/osteoclast) and cartilage (chondroblast /chondroclast) promotes osteoarthritis and osteoporosis…
The loss of membrane fluidity at the level of bronchial epithelial cells promotes a deficiency in the phagocytosis of dust and bacteria causing asthma, emphysema, bronchitis, chronic respiratory failure…
The loss of membrane fluidity at the level of the cells in the cochleovestibular promotes hearing disorders (hypoacusia, tinnitus), vertiginous syndromes…
- The loss of membrane fluidity at the level of the intestinal cells (enterocytes) promotes the reduction of nutrient capture, the phenomenon of malabsorption, deficiencies in vitamins, minerals, micronutrients…
- The loss of membrane fluidity at the level of cells in the liver (hepatocytes) promotes disorders of the detoxification and synthesizing metabolism, causing a risk of poisoning, liver failure, liver metabolism disorders of triglycerides (hypertriglyceridemia) and cholesterol (hypercholesterolemia with hyper-LDL-cholesterolemia)…
The loss of membrane fluidity at the level of renal cells promotes a deficiency in plasma, troubles of osmotic pressure filtration, or even a risk of kidney failure…
Needs in omega 3
Contributions recommended in omega 3 are between 2 and 3 g per day for adults (including = 500 minimum mg EPA + DHA intake). As seen previously, the precursor of the omega 3 is the acid alpha linolenic of which desaturation and elongation lead to two fatty acids, EPA and DHA. They are the two fatty acids we’re talking about when it comes to omega 3.
Omega 3 intake
Omega 3 are mainly present in fatty fish from cold seas as in nuts and vegetable oils like rapeseed, soy, nuts… The cooking method, the origin of the fish, the geographical origin of the animal, its food, the temperature of the water… can change the input. Fatty acids are fragile to cook.
Special case of DHA acid (acid cervonic)
The DHA is preponderant in the brain and represents 95% of the omega 3 brain fatty acids, hence its name cervonic acid. It brings the fluidity necessary for good circulation of electrical impulses. Without sufficient DHA the brain cannot function normally.
Disruption of the Omega 3/6 report in favor of the omega-6 promotes the production of inflammatory molecules (prostaglandins). A reduction in DHA acid destabilizes the production of prostaglandins, creating inflammation at the origin of the “syndrome of irritation of the brain” whose mental illness is the consequence.
Low levels of DHA have been linked to low levels of serotonin, even in correlation with an increase in trends to depression, the risk of suicide, violence…
The issue of omega 3 must be integrated into a global vision, in interaction with other nutrients (carbohydrates, protein, fat, vitamins, minerals, trace elements,…), and not taken in an isolated manner as part of the nutritional schemes of the sportsman. Omega 3 are not a myth, it is a reality, and their daily consumption is far too low. So, to your plates…
Sports Dietitian Nutritionist