Generality
In articles on essential fatty acids in the omega six and omega three series , one often comes across the generic term linolenic acid .
In reality, when talking about linolenic acid it is very important to specify whether it is:
- Alpha linolenic acid , an omega three contained in fish and some vegetable oils , particularly in canola , hemp , soy , walnut , sage , kiwi and flax oil
- Gamma linolenic acid , an omega six found in some vegetable oils, especially blackcurrant oil and borage oil
In fact, both the chemical structure and the metabolic role of the two fatty acids in the body are different.
We also recall how the term linolenic acid should not be confused with the term linoleic acid (LA; 18:2, ω6).
Let’s go into detail to understand better.
Alpha linolenic acid
Alpha linolenic acid (ALA) is an essential fatty acid known as the progenitor of the omega threes .
It is considered the most important of the omega 3 family since it is the only truly essential; in fact, starting from alpha linolenic acid, the human body synthesizes two metabolically active semi-essential fatty acids: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
This transformation is not always completely effective (it can remain compromised with old age , pharmacological therapies, alcoholism , malnutrition, etc. ).
EPA and DHA are especially important for their structural ( cell membrane and nervous tissue as well as ocular) and metabolic ( anti-inflammatory , hypotriglyceride-lowering , hypotensive, ” blood thinner ” etc.) activity.
The nutritional source of these two semi-essential fatty acids is made up of foods that fall into the category of fishery products and related oils.
Gamma linolenic acid
Gamma linolenic acid (GLA) is a semi-essential omega 6 fatty acid . It is produced by the body using the progenitor molecule of the same group, called linoleic acid , as a substrate (the conversion is enzymatic and uses the same catalyst as the omega 3). Also the production of gamma linolenic acid is not always completely effective, for the same reasons we mentioned in the previous chapter. This lipid is also present in foods , for example: hemp seeds , oats and barley , in spirulina algae
, in borage oil, evening primrose oil , blackcurrant seed oil and obviously hemp oil.
Gamma linolenic acid is in turn the precursor of dihomogamma linolenic acid (DGLA), the third direct source of eicosanoids (together with arachidonic acid – AA – and EPA). Specifically, DGLA appears to exclusively produce one type of prostaglandin and one type of thromboxane with an anti-inflammatory and immunomodulatory action.
However, we must not forget that from the DGLA the body can further obtain AA acid, which in turn has a proinflammatory function .
Linoleic acid
Linoleic acid (LA) is an essential fatty acid with 18 carbon atoms, progenitor of the omega six, of which seed oils in general and olive oil are rich .
For some years it was hypothesized that an excess of linoleic acid, typical of the Western diet , in the face of a reduced intake of alpha linolenic acid, could be considered a risk factor for the development of inflammatory diseases, such as atherosclerosis and cardiovascular ( heart attack , thrombosis , arrhythmia ), rheumatoid arthritis , osteoporosis , mood disorders, cancer , diabetes and obesity.
In reality, this effect is more attributable to the excess of other omega 6s, in particular of arachidonic acid (AA – partially synthesized by the body from LA), which represents the most abundant polyunsaturated fatty acid in foods of animal origin .
To cancel the risks of an excess of omega 6 and a lack of alpha linolenic acid, it is sufficient to regularly consume 2-3 portions of sea fish , both fresh and frozen, a week. Particularly rich in alpha linolenic acid are the meats of fatty fish that populate cold marine waters, such as cod , salmon , tuna and mackerel, but also herring , sardines and oily fish in general; other excellent sources are fish oil , cod liver oil , krill oil and algae oil .
Directions
When to use alpha linolenic acid?
Supplements should be used especially when the diet is unable to compensate for nutritional needs .
Furthermore, it may be useful to increase the intake of linolenic acid, EPA and DHA to normalize some excess metabolic values, such as: blood pressure , triglyceridemia , damage inflicted by hyperglycemia and type 2 diabetes mellitus , etc.
Statistically, the deficit mainly affects EPA and DHA, which are even more important in the diet of the pregnant woman , the nurse and the young childup to two years of life.
To ensure the intake of ALA, it is sufficient to consume the right portions of cereals , legumes , fruit and vegetables , prefer unprocessed wholemeal forms , eat at least 50% of raw fruit and vegetables and, scrupulously, partially replace the extra virgin olive oil with another oil rich in omega three (such as chia , flax, kiwi, etc.) to be used raw.
The demand for omega 3 increases with caloric expenditure and overall metabolic effort; usually it is not necessary to use supplements based on alpha linolenic acid, while it seems useful to increase EPA and DHA (especially in the case of a vegetarian or vegan diet , intolerance to fish- flavored supplements, etc.).
When to use gamma linolenic acid?
Currently, no morbidities related to GLA deficiency are known, except those related to linoleic acid (LA).
In natural medicine, considering it useful for its anti-inflammatory action, gamma linolenic acid is prescribed against autoimmune diseases , arthritis , atopic dermatitis (classic indication) and premenstrual syndrome .
Gamma linolenic acid exerts an anti-inflammatory function mainly linked to the formation of DGLA; on the other hand, from the latter the cellular metabolism is also capable of obtaining AA with an inflammatory action.
It is likely that it is because of this promiscuity that supplementation with gamma linolenic acid does not offer clearly describable results.
Properties and Efficacy
What benefit has alpha linolenic acid shown during studies?
Due to the reduced ability to synthesize EPA and DHA in the body, the health benefits of a supplementation based on vegetable oils rich in alpha linolenic acid are much lower than those obtainable through the consumption of fish oil or other supplements rich in EPA and DHA.
The functions of these last two semi-essential fatty acids make their nutritional contribution a real panacea for the prevention and therapy of cardiovascular diseases, for the nervous and ocular development of the fetus and the child, for the maintenance of the integrity and brain function in the geriatric age, for the fight against certain types of depression, etc.
For more information, see the dedicated article.
What benefit has gamma linoleic acid shown during studies?
The usefulness of supplementing with gamma linolenic acid does not rely on scientifically proven evidence.
Doses and Method of Use
How much alpha linolenic acid to take?
The minimum amount of alpha linolenic acid, essential to maintain health, is not well defined.
Taking into account the recommendations of the LARN, alpha linolenic acid and other omega 3 should represent about 0.5-2.0% of total calories .
In the diet of an average adult, this percentage corresponds to 2-3 g per day.
Using a supplement (in liquid form or in capsules or capsules), it would be advisable not to exceed 3 g per day (which is added to the food content).
We remind you that it is important to store these products in an appropriate manner, shielding them from light, oxygen and heat, to keep their nutritional functions intact.
How much gamma linolenic acid to take?
As it is not totally essential and has no obvious metabolic impact, there are no specific recommendations regarding the minimum and maximum intake of GLA.
Side effects
The side effects of taking ALA and GLA are few and far between.
Some are: gastrointestinal discomforts such as belching , nausea , abdominal cramps , dyspepsia and diarrhea (more frequent in the supplement with EPA and DHA).
Impaired blood coagulation has been observed very rarely.
Metabolic peroxide is considered even more infrequent (connected above all to overdoses of any polyunsaturated fat), as are serious alterations of certain systems.
Contraindications
When should alpha linolenic acid and gamma linolenic acid not be used?
Products based on ALA and GLA must be absolutely avoided in case of allergy or intolerance to the ingredients that compose them.
Moreover, it is not recommended to combine them with certain pharmacological therapies (see below).
Drug interactions
What drugs or foods can modify the effect of alpha linolenic acid and gamma linolenic acid?
The intake of ALA and GLA must be avoided in case of pharmacological therapies based on:
- Anticoagulants ( coumadin , sintrom , acenocoumarol ), aspirin , non-steroidal anti-inflammatory drugs , garlic and ginkgo biloba : they would increase the risk of bleeding due to the double antiplatelet effect .
- Oral hypoglycaemics : it is advisable to consult your doctor before starting alpha-linolenic acid-based supplementation, even if the hypoglycaemic power, mainly linked to the function of EPA and DHA, is not well defined and sometimes seems not very relevant.
Precautions for Use
What do you need to know before taking alpha linolenic acid and gamma linolenic acid?
First of all, it is advisable to consult a nutrition professional to evaluate the real need for supplementation based on ALA and GLA.
Secondly, it is imperative that you carefully read the composition, side effects, contraindications and drug interactions.
Finally, although the integration of essential fatty acids plays a beneficial role in many situations ( pregnancy , breastfeeding , metabolic disorders, etc.) it is essential to consult your doctor before taking it.
