Alpha-linoleic acid

Omega-3 fatty acids play a central role in a healthy diet. The most common form is alpha-linolenic acid, often abbreviated to ALA. This is a polyunsaturated fatty acid that forms the basis of the omega-3 family. What makes ALA special is its "essential" designation. This means that the human body cannot produce this specific fatty acid itself, even though it is involved in various biological processes. Therefore, we are completely dependent on external sources of ALA through food for our ALA status.

While attention often focuses on marine fatty acids like EPA and DHA, ALA plays a fundamental role as a precursor. In the body, ALA can be converted into these longer-chain fatty acids, although in practice, this process is often limited. Nevertheless, an adequate intake of the plant-based variety remains essential for a balanced fatty acid balance.

Nutritionist: clairetunzi@vaud.nl Gebruiker

Biological action and conversion

At the molecular level, alpha-linolenic acid is distinguished by the presence of three double bonds in an eighteen-carbon chain. The first double bond is located in the third position from the methyl terminus, hence the term "omega-3." This structure determines the fluidity and functionality of cell membranes in the body.

When ALA is consumed, a small portion undergoes an enzymatic process in the liver to be converted into eicosapentaenoic acid (EPA) and ultimately docosahexaenoic acid (DHA). Scientific data indicates that this conversion rate is relatively low, often below 15%. Factors such as age, gender, and the ratio of omega-6 fatty acids in the diet influence how efficiently this process occurs. This underscores the importance of consistently consuming high-quality sources to maintain internal stores.

Primary plant sources

Alpha-linolenic acid is primarily found in the seeds and oils of specific plants. For those seeking optimal intake, the following sources are most effective:

Flaxseed and flaxseed oil: With a significant ALA content (about 55% of the oil), this is one of the most concentrated sources.
Chia seeds: These seeds are not only rich in fiber, but also contain a significant amount of omega 3 (about 18%).
Walnuts: Among other nutrients, walnuts provide about 10% of linolenic acid.
Hemp seed: A source known for a favorable ratio of different fatty acids.
Rapeseed oil and soybean oil: These oils are often used in cooking and contribute subtly to your daily intake.

It's important to note that the bioavailability of ALA from whole seeds, such as flaxseed, is lower because the hard shell makes digestion difficult. Therefore, grinding the seeds or using cold-pressed oil is preferred for better absorption.

Stability and maintenance of quality

A crucial aspect of alpha-linolenic acid is its vulnerability to oxidation. Due to their polyunsaturated structure, ALA-rich oils are highly sensitive to light, heat, and oxygen. When these fatty acids are exposed to high temperatures, they can lose their integrity and oxidize.

To preserve their nutritional value, it's advisable to use ALA-rich oils, such as flaxseed oil, cold and store them in a cool, dark place. When heating in the kitchen, it's wiser to choose fats with higher thermal stability to prevent the formation of unwanted substances and ensure the active effects of omega-3s.

The role of ALA in mental balance

The relationship between fatty acid intake and neurological well-being is a growing field of research. Omega-3 fatty acids are present in high concentrations in the brain, where they contribute to the structure of neural membranes. While DHA is often considered the primary "brain fatty acid," ALA plays a supporting role as a source.

Dietary research suggests that a stable intake of essential fatty acids contributes to the maintenance of normal cognitive function, especially as we age. A deficiency of these fatty acids can lead to subtle changes in cell communication. For those who adopt a conscious lifestyle, an adequate ALA status is therefore a foundation for both physical and mental vitality.

Summary

Alpha-linolenic acid is the essential plant-based source of omega-3 fatty acids. As an essential nutrient, it plays a role in various biological systems and serves as a building block for EPA and DHA. By choosing high-quality sources like flaxseed, walnuts, and chia seeds, and consuming them carefully, you'll lay a solid foundation for your overall health.

FAQ

What is the recommended daily intake of ALA? Generally, an intake of approximately 1.2 to 2 grams of alpha-linolenic acid per day is recommended for adults to meet their basic needs.

Is ALA the same as fish oil? No, ALA is a plant-based omega-3 fatty acid with a shorter chain (18 carbon atoms), while fish oil mainly contains the longer-chain fatty acids EPA and DHA.

Can I use ALA-rich oil for frying? It's not recommended to heat oils with a high ALA content, such as flaxseed oil, at high temperatures due to their low oxidation stability. It's best to use them cold in salads or shakes.

How do I recognize an omega-3 deficiency? An insufficient omega-3 status can manifest itself in various subtle symptoms. A blood test can provide definitive information about the exact fatty acid levels in your body.