In the world of nutrition, certain nutrients stand out for their remarkable health benefits, and alpha-linolenic acid (ALA) is one such nutrient. As an essential omega-3 fatty acid, ALA plays a crucial role in maintaining optimal health and well-being.
While it may not be as well-known as other omega-3 fatty acids like EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), ALA holds significant importance for the body's various physiological functions.
In this article, we'll provide you a comprehensive understanding of alpha-linolenic acid, exploring its definition, importance, sources, health benefits, dietary options, and supplementation. By delving into the world of ALA, you can grasp its significance in maintaining a healthy lifestyle
What is Alpha-linolenic Acid?
Alpha-linolenic acid (ALA) is a type of essential omega-3 fatty acid. It is classified as an "essential" fatty acid because the body cannot produce it on its own and must obtain it through dietary sources [1].
ALA is a polyunsaturated fat characterized by the presence of three double bonds in its carbon chain. Its chemical structure and unique properties make it a vital nutrient for various physiological functions in the body.
Importance of ALA for the Body
ALA plays a crucial role in maintaining optimal health and functioning of the body. It serves as a building block for producing other omega-3 fatty acids, namely eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
These fatty acids are essential for the proper functioning of the brain, cardiovascular system, and other vital organs. ALA also exhibits anti-inflammatory properties, which can help reduce chronic inflammation in the body.
Chronic inflammation has been linked to various health conditions, including heart disease, diabetes, and certain types of cancer [2].
The importance of ALA extends to its role in maintaining the integrity and fluidity of cell membranes, regulating gene expression, supporting healthy hormone production, and promoting the synthesis of prostaglandins, which are lipid compounds involved in various physiological processes [3].
Sources of Alpha-linolenic Acid
There are several dietary sources of alpha-linolenic acid, with plant-based foods being the primary providers.
Some of the richest sources of ALA include flaxseeds, chia seeds, hemp seeds, walnuts, and soybeans. These foods not only contain ALA but also offer additional nutritional benefits such as fiber, protein, vitamins, and minerals.
Certain plant oils, such as flaxseed oil, canola oil, and soybean oil, are also excellent sources of ALA, all of which will be explored in detail later on.
See more natural sources of ALA below.
Alpha-linolenic Acid and Omega-3 Fatty Acids
Understanding Omega-3 Fatty Acids
Omega-3 fatty acids are a group of polyunsaturated fats that are vital for optimal health. They are classified as essential fatty acids because the body cannot produce them on its own and must acquire them through dietary sources [4].
There are three main types of omega-3 fatty acids: ALA, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). ALA is primarily found in plant-based sources, EPA and DHA are predominantly obtained from marine sources, such as fatty fish, fish oils, and algae.
Omega-3 fatty acids play numerous roles in the body. They are critical components of cell membranes, the production of important signaling molecules called eicosanoids, which are involved in regulating inflammation, blood clotting, and blood vessel dilation [5].
While EPA and DHA are considered more biologically active and readily utilized by the body, ALA is still important as a precursor for their synthesis.
ALA, EPA, and DHA: The Omega-3 Connection
Alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) are interconnected omega-3 fatty acids, each with their unique functions and contributions to human health.
ALA serves as the precursor for EPA and DHA in the body. When ALA is consumed it undergoes a series of enzymatic conversions to eventually produce EPA and DHA.
EPA and DHA are primarily obtained through direct consumption of marine sources such as fatty fish, fish oils, and algae. These long-chain omega-3 fatty acids are highly bioavailable and readily utilized by the body.
They play critical roles in various physiological processes, particularly in the brain and cardiovascular system [4].
EPA is known for its anti-inflammatory properties. It helps regulate the production of pro-inflammatory molecules in the body and promotes the synthesis of anti-inflammatory compounds.
By modulating inflammation, EPA can contribute to the management of chronic inflammatory conditions and potentially reduce the risk of cardiovascular disease [6].
DHA is highly concentrated in the brain and plays a crucial role in brain development and function. It is a major structural component of the brain and supports healthy cognitive processes, memory, and mood regulation. DHA is especially important during pregnancy and early childhood for optimal brain development [7].
While the conversion of ALA to EPA and DHA is limited, it still provides a foundation for the synthesis of these long-chain omega-3 fatty acids and contributes to overall omega-3 fatty acid intake.
Conversion of ALA to EPA and DHA
The conversion of alpha-linolenic acid (ALA) to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the body is a complex process that involves several enzymatic steps.
ALA is the precursor to EPA and DHA, but the conversion efficiency is relatively low, leading to limited amounts of EPA and DHA being synthesized. The conversion of ALA to EPA occurs through a series of desaturation and elongation reactions.
The activity of enzymes that take part in these conversions can vary among individuals, and factors such as genetics, diet, and overall health status can influence conversion efficiency.
The conversion rates of ALA to EPA and DHA are estimated to be less than 5% and less than 0.5%, respectively. This means that consuming high amounts of ALA does not necessarily guarantee a significant increase in EPA and DHA levels in the body [8].
Given the limited conversion efficiency, direct consumption of EPA and DHA from marine sources becomes crucial for obtaining optimal levels of these long-chain omega-3 fatty acids.
Fatty fish such as salmon, mackerel, and sardines are rich sources of EPA and DHA. Additionally, fish oil supplements and algae-based supplements provide concentrated amounts of these omega-3 fatty acids.
Health Benefits of Alpha-linolenic Acid
Alpha-linolenic acid (ALA) offers a range of health benefits, contributing to the overall well-being of individuals. Let's explore some of the key health benefits associated with ALA.
Cardiovascular Health
It is believed that ALA can help lower blood pressure, reduce inflammation, improve endothelial function, and positively impact lipid profiles.
Blood Pressure Regulation
Hypertension, or high blood pressure, is a major risk factor for cardiovascular disease.
Some studies indicate that ALA intake may contribute to the reduction of blood pressure levels. However, further research is needed to establish a definitive link and optimal dosage [9].
Inflammation and Endothelial Function
ALA possesses anti-inflammatory properties, and it may help decrease systemic inflammation and improve endothelial function.
By reducing inflammation and enhancing endothelial health, ALA could potentially contribute to the prevention of atherosclerosis and other cardiovascular conditions [10].
Lipid Profile
Maintaining a healthy lipid profile is vital for cardiovascular health. ALA has been associated with reductions in total cholesterol, LDL cholesterol (commonly known as "bad" cholesterol), and triglyceride levels [11].
These effects may be modest compared to those of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) found in fatty fish, but they still hold potential benefits, especially for individuals with limited access to marine-derived omega-3 sources.
Inflammation Regulation
Influence on Immune System
ALA plays a role in modulating immune cell function and activity. It helps regulate the production and activity of immune cells involved in the inflammatory response, such as macrophages and leukocytes [12].
By exerting control over these immune cells, ALA helps prevent excessive and prolonged inflammation, promoting a balanced immune response.
Impact on Inflammatory Conditions
Studies have indicated that increased intake of ALA-rich foods or ALA supplementation can lead to reduced inflammation and improved symptoms in conditions like rheumatoid arthritis, inflammatory bowel disease, and asthma [13, 14, 15].
Brain Health
The brain relies on these fatty acids for proper development and ongoing maintenance of its cell membranes. They also contribute to the production of signaling molecules and support the overall health of brain cells
Cognitive Function and Aging
Research indicates that a diet rich in ALA may be associated with improved cognitive performance, memory retention, and a reduced risk of cognitive decline, particularly in older adults. However, more studies are needed to establish a clear cause-and-effect relationship [16].
Neuroprotective Properties
ALA can counteract oxidative stress and inflammation in the brain. These protective mechanisms are thought to contribute to the prevention or reduction of neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases [17].
Mental Well-being and Mood
A study published in 2020 on depressed patients, found that ALA leads to higher levels of BDNF (Brain-derived neurotrophic factor which plays an important role in neuronal survival and growth0 and an improved depressive status [18].
Weight Management
While the research is ongoing, several mechanisms suggest how ALA may influence body weight:
Appetite Regulation
Research suggests that ALA can increase the production of the satiety hormone, leptin, which signals fullness and reduces food intake.
By promoting satiety, ALA may contribute to better portion control and reduced calorie consumption, aiding in weight management efforts [19].
Enhanced Fat Burning
ALA has been shown to enhance fat oxidation, which is the process of utilizing stored fat as a source of energy.
By increasing the rate at which the body burns fat, ALA may help support weight loss or prevent weight gain [20].
Improved Insulin Sensitivity
Poor insulin sensitivity can lead to insulin resistance and an increased risk of weight gain and metabolic disorders like type 2 diabetes.
Studies suggest that ALA may improve insulin sensitivity, allowing the body to more effectively utilize glucose for energy and reducing the likelihood of excess fat storage [21].
Skin Health
ALAs helps maintain the integrity and barrier function of the skin, promoting hydration and preventing moisture loss [22].
It helps neutralize free radicals that can damage skin cells and accelerate aging. By reducing oxidative stress, ALA minimizes the appearance of fine lines, wrinkles, and age spots.
It supports collagen production in the skin, which is crucial for maintaining its elasticity and firmness, and with its anti-inflammatory properties that may help alleviate skin conditions like eczema and psoriasis.
Dietary Sources of Alpha-linolenic Acid
Alpha-linolenic acid (ALA) is predominantly found in plant-based sources. Including these sources in your diet is an excellent way to ensure an adequate intake of this essential omega-3 fatty acid. Let's explore some of the key dietary sources of ALA.
Plant-Based Sources
Plant-based foods are rich sources of ALA, making them suitable for individuals following vegetarian or vegan diets [23]. Some of the top plant-based sources of ALA include:
Flaxseeds: These small seeds are a powerhouse of ALA, providing the highest concentration among plant-based sources. Ground flaxseeds are more easily digestible and can be sprinkled on cereals, yogurt, or added to smoothies.
Chia Seeds: Chia seeds are another excellent source of ALA and offer additional nutritional benefits like fiber and minerals. They can be added to baked goods, oatmeal, or used as an egg substitute in recipes.
Hemp Seeds: Hemp seeds are a versatile source of ALA, protein, and healthy fats. They can be sprinkled on salads, blended into smoothies, or incorporated into homemade granola bars.
Walnuts: Walnuts are not only a delicious snack but also a rich source of ALA. They can be eaten on their own, added to salads, or used in baking for an extra nutty flavor.
Soybeans: Soybeans, including edamame and tofu, provide a good amount of ALA. These versatile legumes can be used in various dishes like stir-fries, soups, or salads.
Nuts and Oils Rich in ALA
In addition to the plant-based sources mentioned above, certain nuts and oils are also rich in ALA [24]:
English Walnuts: English walnuts contain significant ALA and make a convenient snack or ingredient in recipes.
Flaxseed Oil: Flaxseed oil is a concentrated source of ALA. It can be used as a dressing for salads or added to smoothies.
Canola Oil: Canola oil is another option that contains ALA. It can be used for cooking, baking, and sautéing.
Other Sources
While plant-based sources are the primary providers of ALA, it's worth noting that some animal-based products may also contain small amounts of ALA due to the animals' consumption of ALA-rich plants. However, the levels are relatively low compared to plant-based sources.
Leafy Green Vegetables include spinach, kale, Brussels sprouts, and watercress. Incorporating these vegetables into your diet can provide a modest amount of ALA along with other essential nutrients [25].
Legumes such as lentils, kidney beans, and chickpeas, also contain ALA. While they are not as concentrated in ALA as some other sources, including legumes in a well-rounded plant-based diet can contribute to overall ALA intake [26].
Berries particularly raspberries and blackberries, contain small amounts of ALA. While they may not be primary sources of ALA, incorporating these antioxidant-rich fruits into your diet can contribute to overall nutritional balance and support overall health [27].
Seaweed especially wakame and nori, contain ALA. It not only provides ALA but also offers various other minerals, vitamins, and antioxidants [28].
Alpha-linolenic Acid Supplements
Supplementation can be an option for individuals who struggle to meet their alpha-linolenic acid (ALA) needs through dietary sources alone.
ALA supplements are available in various forms and can provide a convenient way to ensure an adequate intake of this essential omega-3 fatty acid. Let's explore the different aspects of ALA supplementation.
ALA Supplements: Forms and Dosage
ALA supplements are commonly available in the form of capsules or soft gels. These supplements typically contain a concentrated dose of ALA derived from plant sources, such as flaxseed oil.
The recommended dosage of ALA varies depending on age, sex, health status, and specific health goals.
However, a general guideline is to aim for a daily intake of 1.6 grams of ALA for adult men and 1.1 grams for adult women. It is important to note that this dosage refers to total omega-3 intake, including ALA, EPA, and DHA [29].
For specific health conditions or goals, such as managing cardiovascular health or reducing inflammation, higher doses of ALA or additional supplementation with EPA and DHA may be recommended.
Considerations for Choosing ALA Supplements
When selecting an ALA supplement, there are a few factors to consider:
Quality and Purity: Look for supplements that are third-party tested for quality, purity, and potency. This ensures that the supplement is free from contaminants and provides the stated amount of ALA.
Source of ALA: Check the source of ALA in the supplement. High-quality sources include organic flaxseed oil or other plant-based oils rich in ALA.
Additional Ingredients: Pay attention to the additional ingredients in the supplement. Some may contain additives, fillers, or allergens that you may want to avoid.
Storage and Expiration: Check the storage instructions and expiration date of the supplement to ensure its freshness and effectiveness.
Consulting with a Healthcare Professional
Before starting any supplementation regimen, it is advisable to consult with a healthcare professional or registered dietitian, especially if you have any underlying health conditions or are taking medications.
They can assess your individual needs, provide personalized recommendations, and ensure that ALA supplementation is safe and appropriate for you.
Additionally, a healthcare professional can help monitor the effectiveness of supplementation and make adjustments as needed.
Physicians can also guide you on incorporating dietary sources of ALA into your daily routine to complement the supplementation regimen. Remember that supplements should not replace a balanced diet but rather complement it when necessary.
Frequently Asked Questions
Is ALA an omega-3 fatty acid?
Yes, ALA is classified as an omega-3 fatty acid. It is the precursor to other omega-3 fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
What is ALA supplement used for?
ALA supplements are commonly used to ensure an adequate intake of omega-3 fatty acids. They can support cardiovascular health, brain function, inflammation regulation, and overall well-being.
Is ALA good for cholesterol?
ALA has been shown to have positive effects on cholesterol levels. It can help reduce LDL cholesterol (often referred to as "bad" cholesterol) and triglycerides, which are both risk factors for cardiovascular disease.
Is ALA good for fat loss?
While ALA has been associated with weight management benefits, it is not a natural fat loss supplement. ALA's ability to increase feelings of fullness and its anti-inflammatory properties may contribute to healthy weight management.
What is the best type of ALA?
There is no single "best" type of ALA. The key is to incorporate a variety of ALA-rich foods into your diet, such as flaxseeds, chia seeds, hemp seeds, and walnuts. This ensures a diverse range of nutrients and promotes overall health.
Conclusion
Alpha-linolenic acid (ALA) plays a crucial role in promoting overall health and well-being.
As an essential omega-3 fatty acid, ALA offers numerous benefits, including supporting cardiovascular health, reducing inflammation, promoting brain function, aiding in weight management, and enhancing skin health.
While ALA is predominantly found in plant-based sources, supplementation can be considered to ensure an adequate intake.
When choosing ALA supplements, it's important to prioritize quality, consult with healthcare professionals, and complement supplementation with a balanced diet rich in ALA sources.
By incorporating ALA into our daily lives, we can harness its potential to optimize our health and vitality.
References
α-Linolenic acid: nutraceutical, pharmacological and toxicological evaluation. Retrieved from https://pubmed.ncbi.nlm.nih.gov/24859185/
The effects of alpha-lipoic acid supplementation on inflammatory markers among patients with metabolic syndrome and related disorders. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5989440/
Effect of dietary alpha-linolenic acid on the activity and gene expression of hepatic fatty acid oxidation enzymes. Retrieved from https://pubmed.ncbi.nlm.nih.gov/11237206/
Omega-3 Fatty Acids. Retrieved from https://ods.od.nih.gov/factsheets/Omega3FattyAcids-Consumer/
Fatty acids from fish: the anti-inflammatory potential of long-chain omega-3 fatty acids. Retrieved from https://pubmed.ncbi.nlm.nih.gov/20500789/
Role of EPA in Inflammation: Mechanisms, Effects, and Clinical Relevance. Retrieved from https://ncbi.nlm.nih.gov/pmc/articles/PMC8961629/
Health benefits of docosahexaenoic acid (DHA). Retrieved from https://pubmed.ncbi.nlm.nih.gov/10479465/
Efficiency of conversion of alpha-linolenic acid to long chain n-3 fatty acids in man. Retrieved from https://pubmed.ncbi.nlm.nih.gov/11844977/
Effect of α-linolenic acid on 24-h ambulatory blood pressure in untreated high-normal and stage I hypertensive subjects. Retrieved from https://pubmed.ncbi.nlm.nih.gov/30392473/
Effect of Alpha-Lipoic Acid Supplementation on Endothelial Function and Cardiovascular Risk Factors in Overweight/Obese Youths. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6412308/
Effects of α-linolenic acid intake on blood lipid profiles. Retrieved from https://pubmed.ncbi.nlm.nih.gov/32643951/
The Immunomodulatory Effect of Alpha-Lipoic Acid in Autoimmune Diseases. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6446120/
High erythrocyte levels of the n-6 polyunsaturated fatty acid linoleic acid are associated with lower risk of subsequent rheumatoid arthritis in a southern European nested case. Retrieved from https://pubmed.ncbi.nlm.nih.gov/29436473/
α-Linolenic acid (ALA) is an anti-inflammatory agent in inflammatory bowel disease. Retrieved from https://pubmed.ncbi.nlm.nih.gov/26350254/
Alpha-linolenic acid ameliorates bronchial asthma features in ovalbumin-sensitized rats. Retrieved from https://pubmed.ncbi.nlm.nih.gov/30993723/
Oral Administration of Alpha Linoleic Acid Rescues Aβ-Induced Glia-Mediated Neuroinflammation and Cognitive Dysfunction in C57BL/6N Mice. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7140708/
Alpha-linolenic acid is a potent neuroprotective agent against soman-induced neuropathology. Retrieved from https://pubmed.ncbi.nlm.nih.gov/22884490/
Flaxseed oil supplementation on severity of depression and brain-derived neurotrophic factor. Retrieved from https://www.tandfonline.com/doi/pdf/10.1080/10942912.2020.1812639
The alpha linolenic acid content of flaxseed is associated with an induction of adipose leptin expression. Retrieved from https://pubmed.ncbi.nlm.nih.gov/22031167/
Alpha-Linolenic Acid-Enriched Butter Promotes Fatty Acid Remodeling and Thermogenic Activation in the Brown Adipose Tissue. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7019653/
Alpha-linolenic acid improves insulin sensitivity in obese patients. Retrieved from https://pubmed.ncbi.nlm.nih.gov/23648351/
α-Linolenic acid and linoleic acid modulate the lipidome and the skin barrier of a tissue-engineered skin model. Retrieved from https://www.sciencedirect.com/science/article/pii/S1742706121007704
Health benefits of plant-derived α-linolenic acid. Retrieved from https://pubmed.ncbi.nlm.nih.gov/24898228/
Oils rich in alpha linolenic acid. Retrieved from https://www.ocl-journal.org/articles/ocl/full_html/2020/01/ocl200104/ocl200104.html
The alpha-linolenic acid content of green vegetables commonly available in Australia. Retrieved from https://pubmed.ncbi.nlm.nih.gov/11582857/
A Comprehensive Characterisation of Volatile and Fatty Acid Profiles of Legume Seeds. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6963610/
A comparative study of the fatty acid profile of common fruits and fruits claimed to confer health benefits. Retrieved from https://www.sciencedirect.com/science/article/pii/S0889157522002757
Fatty acid profiles of the main lipid classes of green seaweeds from fish pond aquaculture. Retrieved from https://onlinelibrary.wiley.com/doi/full/10.1002/fsn3.511
lpha-Linolenic Acid: An Omega-3 Fatty Acid with Neuroprotective Properties. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4350958/
