Alpha-linolenic acid, what is it?
ALA, or alpha-linolenic acid, is an essential fatty acid in the omega-3 family.
The benefits of omega-3s for cardiovascular health and the nervous system are well known.
ALA is also a precursor to the other two omega-3s, EPA and DHA.
It is therefore important to get enough of it in your diet.
Characteristics of alpha-linolenic acid (ALA)
- Essential fatty acid in the omega-3 family that cannot be synthesised by the body.
- Precursor to EPA and DHA
- Found in flaxseed, rapeseed and walnut oils
- Our omega-3 intake is currently inadequate
- ALA, EPA and DHA are involved in the prevention of cardiovascular and neurodegenerative diseases.
Benefits of a diet rich in alpha-linolenic acid
Synthesis of EPA and DHA
The body can synthesise DHA and EPA from alpha-linolenic acid (ALA).
However, ALA cannot be synthesised by the body.
It is therefore essential to get it from food, as it is an essential omega-3.
EPA and DHA have many benefits for the nervous and cardiovascular systems.
In this sense, an adequate intake of alpha-linolenic acid is a major health benefit.
Cardiovascular health
In the 1950s, during research on the Mediterranean diet, scientists discovered the role of omega-3 in the prevention of cardiovascular disease.
Indeed, omega-3s thin the blood and limit the process of atherosclerosis, one of the main causes of cardiovascular accidents.
However, it is not yet clear what role each of the 3 omegas (EPA, DHA and ALA) plays in this process.
20 foods rich in alpha-linolenic acid (ALA)
Food - Portions - g
- Linseed oil - 15ml (1 tbsp) = 7.7g
- Walnuts - 60ml (1/4 cup) = 2.7g
- Linseed - 15ml (1 tablespoon) = 2.5g
- Walnut oil - 15ml (1 tbsp) = 1.4g
- Lamb - 100g = 1.3g
- Rapeseed oil - 15ml (1 tablespoon) = 1.3g
- Cooked soybeans - 250ml (1 cup) = 1.1g
- Cooked beef - 100g = 1.1g
- Wheat germ oil - 15ml (1tbsp) = 1.0g
- Soya bean oil - 15ml (1 tablespoon) = 0.9g
- Dehydrated walnuts - 15ml (1 tablespoon) = 0.7g
- Plain firm tofu (made with calcium sulphate) - 100g = 0.6g
- Roasted soybeans - 60ml (1/4 cup) = 0.5g
- Roquefort cheese (blue) - 50g = 0.4g
- Dry roasted soybeans - 60ml (1/4 cup) = 0.4g
- Pecan nuts - 60ml (1/4 cup) = 0.3g
- Sprouted radish seeds - 250ml (1 cup) = 0.3g
- Dehydrated pine nuts - 60ml (1/4 cup) = 0.2-0.3g
- Unsalted butter - 15ml (1 tbsp) = 0.2g
Alpha-linolenic acid requirements
The current Recommended Dietary Allowance for ALA is 1%.
This means that 1% of your total daily energy intake should come from alpha-linolenic acid.
Lipids should account for 35-40% of total energy intake.
As an indication, here are the data on adequate intakes of alpha-linolenic acid by population groups:
- Infants 0-6 months = 0.5 g
- Infants 7-12 months = 0.5 g
- Infants 1-3 years = 0.7g
- Children 4 to 8 years = 0.9g
- Boys 9 to 13 years = 1.2g
- Girls 9 to 13 years = 1.0g
- Boys 14 to 18 years = 1.6g
- Girls 14 to 18 years = 1.1g
- Men aged 19 to 50 = 1.6 g
- Women aged 19 to 50 = 1.1g
- Men aged 50 and over = 1.6g
- Women aged 50 and over = 1.1g
- Pregnant women = 1.4 g
- Women who are breastfeeding = 1.3g
Dietary supplements based on omega-3 ALA
Many omega-3 supplements contain alpha-linolenic acid.
They are generally indicated to prevent or treat disorders of the nervous and cardiovascular systems.
However, it is important to remember that supplements are not a substitute for a varied and balanced diet.
ALA deficiency
Insufficient intake of alpha-linolenic acid can lead to deficiencies of EPA and DHA.
These omega-3 fatty acids are essential for the health of the cardiovascular and nervous systems.
An insufficient intake may therefore favour the occurrence of cardiovascular and neurodegenerative diseases.
ALA excess
Due to the diluting effect of omega-3 in the blood, the main risk of excessive omega-3 intake is haemorrhagic.
Interactions with other nutrients
An adequate intake of alpha-linolenic acid promotes the synthesis of EPA and DHA.
An excessive intake of omega-6, on the other hand, reduces the health benefits of alpha-linolenic acid.
The diet should therefore ideally maintain a balance between omega-3 and omega-6.
Chemical properties of ALA
The molecular formula of alpha-linolenic acid is C18H30O2 and its molecular weight is 278.4296 g/mol.
Like all omega-3 fatty acids, ALA has three double bonds, or unsaturations.
The body can convert ALA into EPA and DHA, making it an essential precursor for good health.
Alpha-linolenic acid, on the other hand, cannot be produced in the body and must be obtained from food.