Miracon Science

Alpha-linolenic acid

Synonym(s): hempseed oil, linseed oil, oil extract
Nutrient group: fatty acids

Sources and physiological effects

Dietary sources

Alpha-linolenic acid (ALA) - also called linolenic acid - belongs to  of polyunsaturated omega-3 fatty acids group. The name linolenic acid is derived from the Greek word „linos“ for flax. Linolenic acid is a natural component of triglycerides in many vegetable oils. Linseed oil contains a particularly high proportion of linolenic acid (> 50 % linolenic acid content). But other vegetable oils such as hemp oil, walnut oil, rapeseed oil and soybean oil also contain considerable amounts of linolenic acid.

Vegetable sources of linolenic acid are a good alternative for vegetarians, vegans and people with fish aversion for the supply of omega-3 fatty acids.
 
Physiological effects
Fat metabolism
  • Alpha-linolenic acid is the precursor of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
  • It has a positive influence on cholesterol levels by lowering LDL cholesterol and increasing HDL cholesterol .
  •  
Cardiovascular system
  • Cardioprotective through reduction of vascular inflammation and plaque formation.
Immune system
  • Improvement of immune competence by modulation of the immune response.

Detailed information

Alpha-linolenic acid from linseed oil – a traditional substance in modern medicine
Linseed oil is obtained from the mature seeds of flax (Linum usitatissimum). It was once a popular household remedy for cough, burns and stomach complaints, but today it is used in naturopathy and holistic conventional medicine because of its high content of the essential omega-3 fatty acid alpha-linolenic acid. Linseed oil should always be bought fresh and in small quantities and stored in a dark and cool, place to help retain its fine nutty taste. Due to its preventive and therapeutic properties it is used in complementary micronutrient therapy.
The biosynthesis of essential fatty acids
The human organism cannot synthesize polyunsaturated fatty acids in sufficient quantities or sometimes at all. They are therefore essential, i.e. they must be supplied exogenously from food. In terms of fat, the human body requires two types of basic building blocks, the omega-3 and omega-6  fatty acid compounds. Linoleic acid is serves as the essential starting compound for the omega-6 series and alpha-linolenic acid (ALA) is the starter for the omega-3 series. Linoleic acid (omega-6) can be converted in the body into gamma-linolenic acid and further into arachidonic acid, while alpha-linolenic acid (omega-3) serves as a precursor of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Depending on total energy intake, an exogenous supply of 5-8 g of omega-6 and 1-2 g of omega-3 fatty acids is recommended.
An increased supply of alpha-linolenic acid in food leads to a significant increase in serum concentrations of both alpha-linolenic acid and eicosapentaenoic acid and docosahexaenoic acid (1).
The fatty acid pattern
The fatty acid pattern is the percentage distribution of the different fatty acid types – saturated, monounsaturated and polyunsaturated - in dietary fat intake. In a healthy, balanced diet, the intake of polyunsaturated fatty acids (omega-3 and omega-6) should account for over 7% of the total energy balance. Neither in Austria nor in Germany are these values are reached (2) (3).
If the overall supply of polyunsaturated fatty acids is insufficient, more saturated fatty acids are incorporated into biological membranes. This changes the membrane properties in terms of fluidity and permeability and can manifest itself in a number of clinical symptoms. In addition  to changes in composition of the fat fractions in the blood and liver, skin function disorders with skin rashes, impairment of the immune system and wound healing as well as neurological deficits such as visual disturbances or disturbed surface and depth sensitivity are also evident (4).
High saturated fat content increases cancer risk
Cancer risk is also affected by insufficient intake of polyunsaturated fatty acids. For example, the risk of cancer increases by up to 20% if saturated fatty acids are supplied predominantly. Conversely, an increase in the supply of polyunsaturated fatty acids can significantly reduce the risk of malignant tumors such as breast cancer or prostate cancer (3).
Even more important than the total intake is the ratio of the two different types of polyunsaturated fatty acids, i.e. the quotient from the intake of omega-6 to omega-3 fatty acids.
Multiple unsaturated fatty acids and  their ratios
Both linoleic acid (omega-6) and alpha-linolenic acid (omega-3) are essential dietary components. However, the ratio of these fatty acids to each other must also be taken into account, as they displace each other from the cell membranes and compete in metabolism for the same enzyme systems.
In the modern diet there is a relative excess of omega-6 fatty acids and too little omega-3 fatty acids. This is directly related to the occurrence of many chronic diseases of modern civilisation (5).
The intake of omega-6 fatty acids such as linoleic acid and omega-3 fatty acids such as alpha-linolenic acid should be in a ratio of 5: 1, but is on average 8: 1 (2) in Austria and 7: 1 (3) in Germany. Substitution with alpha-linolenic acid can significantly improve this ratio, increase the overall intake of polyunsaturated fatty acids and reduce the risk of secondary diseases.
Depending on the amount of fatty acid added, different eicosanoids with opposing physiological and biochemical effects are produced from the omega-3 and omega-6 compounds. Omega-6 fatty acids form prostaglandins and leukotrienes of series 2 and 4, which have vasoconstrictive, immunosuppressive, coagulatory and inflammatory properties. Omega-3 fatty acids are precursors of prostaglandins and leukotrienes of series 3 and 5, which show antithrombotic, anti-inflammatory and vasodilatory effects (4).
Linseed oil in prevention and therapy
The high proportion of alpha-linolenic acid and the favorable ratio of unsaturated fatty acids enable linseed oil to be used in a wide range of preventive and therapeutic measures. Several scientific studies show significant results from supplementation with linseed oil. It can reduce the production of inflammatory cytokines (6), help to control total plasma cholesterol and LDL levels (7) and reduce atherogenic plaque formation (8). Linseed oil supplements have also shown a significant improvement in immune competence (9).
Recent studies suggest that the fatty acid pattern could also influence a person's psychosocial behavior. People with low omega-3 and high omega-6 status demonstrate different behaviors than people with high omega-3 and low omega-6 status(10).

Reference values

Parameter Substrate Reference value Description
Alpha - linolenic acid EDTA 5.4 - 18.9 mg/l Omega - 3 - Index

Deficiency symptoms

Impact on Symptoms
Cardiovascular system Additional risk of atherosclerosis
Immune system Increased production of inflammatory cytokines, favors susceptibility to infections and occurrence of atopic dermititis

Administration

 

General mode of administration
 When Alpha-linolenic acid should be taken with meals.

Notes:

Intake should be regular and long-term. The combination with antioxidants is recommended as undesirable lipid peroxidation can limit the biological effectiveness. Administration in persons taking anticoagulants should be under medical supervision.
Side effects 
When taken over a long period of time, omega-3 fatty acids reduce platelet aggregation, the formation of thrombocyte aggregation-promoting thromboxane platelet aggregation promoting platelet formation and lower the level of plasma factor VII and fibrinogen. This moderately prolongs blood coagulation, which may reduce the need for warfarin or phenprocoumon and require dose adjustment.
Contraindications
Acute pancreatitis, cirrhosis, gall bladder inflammation, coagulation disorders

Interactions

Drug interactions
Anticoagluants (e.g. Phenprocoumon, ASS) Can prolong bleeding time and reduce platelet aggregation in high doses with vitamin K–antagonists or ASA (control INR values).
NSAIDs (e.g. ibuprofen, ASS, diclofenac) The anti-inflammatory and immunomodulating effect of omega-3 fatty acids can reduce the need for NSAIDs.
Psychostimulants (methylphenidate) Omega-3 fatty acids can improve the effectiveness of methylphenidate.
Cholesterol-lowering drugs (statins) Support of statin therapy by cardioprotective and lipid modulating effects of omega-3 fatty acids.
Nutrient interactions
Glucosamine Omega-3 fatty acids and glucosamine complement each other in their anti-inflammatory effect in the therapy of inflammatory diseases of the locomotor system.

Description and related substances

Description 
Omega-3-type polyunsaturated fatty acids 
Related substances
Vegetable omega-3 fatty acids:
  • Linseed oil (alpha-linolenic acid)

References

References

1) Tarpila, S. et al. 2002. The effect of flaxseed supplementation in processed foods on serum fatty acids and enterolactone. European Journal of Clinical Nutrition 56(2):157–165. doi:10.1038/sj.ejcn.1601298.

2) Bundesministerium für Gesundheit und Frauen: Österreichischer Ernährungsbericht 2003.

3) Deutsche Gesellschaft für Ernährung: Ernährungsbericht 2004

4) Hahn, A. et al. 2005. Ernährung. Physiologische Grundlagen, Prävention und Therapie.

5) Gröber, U. 2002. Orthomolekulare Medizin. ein Leitfaden für Apotheker und Ärzte. Stuttgart (Wiss. Verlag-Ges.).

6) Calder, P. C. 2012. Omega-3 polyunsaturated fatty acids and inflammatory processes: Nutrition or pharmacology?. British Journal of Clinical Pharmacology. doi:10.1111/j.1365-2125.2012.04374.x.

7) Bloedon, L. T. et al. 2004. Flaxseed and Cardiovascular Risk. Nutrition Reviews 62(1):18–27. doi:10.1111/j.1753-4887.2004.tb00002.x.

9) Kelley, D. S. et al. 1991. Dietary alpha-linolenic acid and immunocompetence in humans. Am J Nutr. 53(1):40-6.

10) Emanuele, E. et al. 2009. Serum omega-3 fatty acids are associated with ultimatum bargaining behavior. Physiology & Behavior 96(1):180–183. doi:10.1016/j.physbeh.2008.09.020.


References Interactions:
Stargrove Mitchell Bebel, Treasure Jonathan, McKee Dwight L.: Herb, Nutrient, and Drug Interactions: Clinical Implications and Therapeutic Strategies. 2008
Gröber Uwe: Mikronährstoffe. Metabolic Tuning – Prävention – Therapie. 3. Auflage, 2011
Gröber Uwe: Arzneimittel und Mikronährstoffe. Medikationsorientierte Supplementierung. 2. Auflage, 2012

 

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