Nutrition Diet: What is DHA extracted from? Exploring Sustainable Algal and Traditional Fish Sources

November 10, 2025 •

3 min read

DHA (docosahexaenoic acid) is not originally produced by fish, but rather by the marine microalgae they consume, making these tiny organisms the true primary source. Understanding what is DHA extracted from provides valuable insight into the most sustainable and pure options available for supplementation and dietary intake.

Quick Summary

DHA is extracted primarily from sustainably cultivated marine microalgae through fermentation and refining. This process yields a pure, plant-based algal oil, representing a potent and environmentally friendly alternative to traditional fish oil, where DHA accumulates via the food chain.

Key Points

Algae is the Primary Source: Microalgae are the original producers of DHA and EPA, which then enter the marine food chain.
Algal Oil is Sustainable: Sourcing DHA directly from microalgae cultivated in closed fermenters is more sustainable than relying on fish stocks, reducing the risk of overfishing.
Purity and Cleanliness: Algal oil produced in controlled environments is less susceptible to contamination from heavy metals and other pollutants found in ocean waters.
Effective for Vegans: Algae-based DHA provides a potent, direct, and plant-based source of omega-3s for individuals on vegan and vegetarian diets.
High Bioavailability: Research indicates that DHA from algal oil is effectively absorbed and utilized by the body, offering a viable alternative to fish oil supplements.
Supports Brain and Eye Health: DHA is a critical structural component for both the brain and the retina, with supplementation benefiting cognitive function and vision across the lifespan.

The Origins of DHA: Tracing the Source

For decades, fish and fish oil have been the primary sources of the essential omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). However, marine microalgae are the original producers of these crucial nutrients, which fish accumulate by consuming these smaller organisms. Since the human body has a low conversion rate of ALA from plants into EPA and DHA, sourcing omega-3s directly from microalgae has become increasingly important.

Extraction of DHA from Microalgae

Modern biotechnology allows for the direct extraction of DHA from specific microalgae strains cultivated in controlled environments, such as Schizochytrium sp. or Crypthecodinium cohnii. This offers a sustainable alternative to fish-based sources. The process involves several steps:

1. Fermentation and Cultivation

Microalgae are grown in closed-tank bioreactors using nutrient-rich mediums for rapid growth and high lipid production. This controlled environment ensures purity.

2. Harvesting and Cell Lysis

After cultivation, the microalgae are harvested, and their cell walls are broken down through methods like enzymatic lysis to release the stored oil.

3. Oil Extraction and Refining

The oil is extracted using solvents like hexane or solvent-free methods such as supercritical CO2 extraction. The crude oil is then refined to remove impurities and improve quality.

Comparison: Algal Oil vs. Fish Oil

Both algal oil and fish oil provide essential DHA and EPA, but they differ in sourcing, purity, and environmental impact. The table below highlights key differences.


Feature	Algal Oil	Fish Oil
Original Source	Primary source, derived directly from microalgae.	Secondary source, derived from fish that have consumed algae.
Sustainability	Highly sustainable, grown in controlled indoor or closed-tank systems, reducing pressure on marine ecosystems.	Sustainability concerns exist due to potential overfishing and impacts on marine habitats.
Purity	Free from contaminants like mercury, dioxins, and PCBs that accumulate in the ocean food chain.	Risk of contamination from pollutants in marine environments, though high-quality products are purified.
EPA & DHA Ratio	Often high in DHA, with varying levels of EPA depending on the algal strain.	Contains a combination of both DHA and EPA.
Dietary Suitability	Suitable for vegan, vegetarian, and plant-based diets.	Unsuitable for vegan or vegetarian diets.
Flavor Profile	Neutral flavor, without the "fishy" aftertaste common with some fish oils.	Can have a strong fishy odor and taste.

The Health Benefits of DHA from Algae

Algal oil provides comparable health benefits to fish oil.

Brain and Cognitive Health

DHA is vital for brain development, cognitive function, memory, and may help reduce the risk of age-related cognitive decline. It may also support mental health.

Eye Health

DHA is a key component of the retina, important for visual acuity and potentially reducing the risk of macular degeneration.

Cardiovascular Health

Omega-3s can lower triglycerides and have anti-inflammatory effects.

Conclusion

DHA is an essential nutrient with microalgae being its true origin. Sustainable algal oil provides a pure and potent alternative to fish oil, benefiting brain, eye, and overall health, particularly for those on plant-based diets or concerned about environmental impact and purity. As demand for omega-3s rises, microalgae offer a responsible nutritional source. For more information, explore resources like the National Institute of Child Health and Human Development website.

Where to find DHA in your diet

Algal Oil Supplements: Direct vegan source from microalgae fermentation.
Fatty Fish: Fish like salmon, mackerel, and sardines accumulate DHA through their diet.
Fortified Foods: Many foods are fortified with DHA from microalgae.
Plant-Based Foods (ALA): Foods like flaxseeds and walnuts contain ALA, which the body converts inefficiently to DHA.

Optimizing your DHA intake

Check Supplement Labels: Ensure sufficient DHA dosage in algal oil supplements.
Monitor Fish Consumption: Follow guidelines for fish intake, especially for species with higher mercury levels.
Consider Bioavailability: DHA from algal oil may be more bioavailable than from fish oil.
Dietary Diversity: Combine different omega-3 sources as relying solely on ALA conversion may not be enough.

Frequently Asked Questions

Yes, DHA from microalgae is molecularly identical to the DHA found in fish oil. The main difference lies in the source and the production method, with algal oil being a direct, primary source and fish oil being a secondary source from the marine food chain.

Both algal oil and fish oil provide beneficial DHA for brain health. Some specialized algal oils can be formulated with a higher ratio of DHA to EPA, which some research suggests may be more beneficial for cognitive function.

Plant-based foods like flaxseed and walnuts contain ALA, an omega-3 precursor. However, the human body’s conversion rate of ALA to DHA is very low and inefficient, so consuming a direct source like algal oil is recommended for optimal DHA intake.

Yes, algal oil is considered a safe and effective source of DHA for pregnant women. DHA is crucial for fetal brain and eye development, especially in the third trimester. DHA supplements are often recommended to ensure sufficient intake.

Algal oil is sourced from microalgae grown in controlled, closed-tank fermenters. This cultivation method completely bypasses exposure to ocean waters, preventing the accumulation of heavy metals, microplastics, and other pollutants often found in wild fish.

The higher cost of algal oil can be attributed to the specialized technology and controlled environment required for its cultivation and extraction. As production scales up, costs are expected to become more competitive with fish oil.

The EPA content in algal oil varies depending on the specific strain of microalgae used. Some strains are rich in DHA, while others contain both EPA and DHA. If both are desired, check the supplement's formulation.