Not only vegetarians and vegans: microalgae supplements also effective for omnivores
They are often presented as an alternative to fish oil for those who do not consume animal products, but microalgae supplements are also a viable option for omnivores. The evidence in a study in the European Journal of Nutrition.
By now this is no longer news: even those who do not consume fish derivatives (such as vegans and some vegetarians) can take in the bioactive Omega 3s present in this source and absent, on the other hand, in the foods allowed in their diets. In fact, microalgae contain EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), the Omega 3s found in fish, and can be used to produce dietary supplements compatible with vegetarian and vegan choice.
Now, however, we also have evidence that these same supplements are good sources of EPA and DHA for omnivores. This was demonstrated in a study published in theEuropean Journal of Nutrition by a group of researchers from theInstituto de Ciencia y Tecnología de Alimentos y Nutrición in Madrid, Spain, coordinated by Pilar Vaquero.
This certainty is good news for all those who do not want or cannot take fish products for reasons other than those that motivate vegetarians and vegans, such as those who do not even like the taste of the most purified and flavored fish oil supplements on the market.
Why prefer EPA and DHA supplements?
The need to prefer dietary supplements containing preformed EPA and DHA is due to the human body's poor ability to produce them from their precursor, alpha-linolenic acid (ALA).
Unfortunately, diet-compatible sources of Omega 3 for those who exclude fish and other seafood products from their table (such as the oft-mentioned nuts, flaxseeds and oils derived from them) do not contain EPA and DHA, but ALA. This, once absorbed, is converted first to EPA and then to DHA through a series of reactions that are so inefficient that less than 5 percent of the available ALA can be converted to ALA; according to some studies, the conversion rate is even lower, especially in men.
Therefore, even by taking "terrestrial" plant-based supplements, vegetarians and vegans risk not meeting their EPA and DHA requirements, especially in circumstances, such as pregnancy or hypertriglyceridemia, in which the amount of bioactive Omega 3 to be taken is increased.
Fortunately, the alternative exists, and it ismicroalgae oil. Like animal sources of marine origin (fish oil, cod liver oil, and krill oil), microalgae oil also contains preformed bioactive Omega 3, especially DHA.
On the other hand, microalgae are at the base of the food chain that causes krill and fish to accumulate precisely DHA and EPA. Today we know how to grow them to make supplements whose ability to increase DHA levels in the blood of vegetarians and vegans has already been documented in more than one circumstance.
An analysis of results obtained in studies evaluating the effects of their intake, published in 2017 in the Journal of Human Nutrition and Dietetics by Joel C Craddock and colleagues, confirmed improvements in both DHA concentrations in plasma, serum, platelets, and red blood cells, and in theOmega 3 Index - an indicator of Omega 3 levels in the body used to assess the risks to heart health-in those who do not eat fish. But are these products also suitable for fish eaters?
Omnivores: when is fish oil not suitable?
Answering this question is important because even among omnivores there are those who prefer not to take fish oil supplements. The most common reason behind this preference is the fishy aftertaste, sometimes felt despite the fact that the ingredients have undergone careful and sophisticated purification processes.
L'krill oil could be an alternative, as long as you are not dealing with a shellfish allergy: that would make it contraindicated.
These and other reasons may also prompt fish eaters to choose microalgae oil specifically as a source for Omega 3 supplementation.
Microalgae oil: the right supplement for everyone
The study published in theEuropean Journal of Nutrition confirmed the effectiveness of a DHA supplement obtained from the microalga Schizochytrium in increasing blood DHA levels in vegan and lacto-ovo-vegetarian adults, adding two important details:
1) To achieve the increase , it is sufficient to take 250 mg of DHA per day, which is the maximum amount that, according to European Commission approvals, can be contributed by a supplement made from oil obtained from Schizochytrium;
2) The same supplement, at the same dosage, also increases blood levels of DHA in omnivorous adults.
Vaquero and coworkers involved 116 volunteers in their research, randomly assigning them to the group that would take either theDHA supplement from microalgae Schizochytrium (containing 625 mg of total lipids, including 250 mg of DHA) or a placebo, which was indistinguishable from the supplement in form and total lipid content (625 mg of olive oil).
Each participant had to take 1 capsule per day, during one of the main meals to maximize DHA absorption, for 5 weeks, after which they did not take any capsules for another 5 weeks. During the next 5 weeks, the two groups were switched: those who had taken the DHA supplement were made to take the placebo, and vice versa. Otherwise, all continued to follow their usual lifestyle (diet and physical activity).
Before the start of the study, all volunteers had to fill out a questionnaire about their health status and lifestyle. Other specific questionnaires were completed by each participant at 5, 10 and 15 weeks after the start of the study to monitor health status, eating habits and capsule intake.
Blood DHA levels were measured in samples taken after 10 hours of fasting before and at 5, 10 and 15 weeks after the start of the study. "Significant effects of diet, treatment and combination diet x treatment were observed," the authors explain in the pages of theEuropean Journal of Nutrition.
In particular, blood levels of DHA:
1) after placebo intake, were greater in omnivores, followed by lacto-ovo-vegetarians and vegans;
2) after taking the microalgae supplement, they increased significantly (compared with placebo) in all three groups, with a relatively stronger effect in vegans, although neither vegans nor lacto-ovo-vegetarians reached the same levels as omnivores;
3) increased similarly in men and women, who were characterized by generally higher DHA concentrations.
"These results," the authors explain, "lead us to conclude that all participants with low or no DHA intake would benefit from taking the DHA supplement tested."
Microalgae supplements are "bioavailable and useful"
"These results," Vaquero and coworkers conclude, "clearly demonstrate that DHA supplements obtained from the microalga Schizochytrium sp. are bioavailable and useful for increasing circulating levels of this important long-chain Omega 3 fatty acid."
The supplements obtained from Schizochytrium, the authors point out, "have great potential," both because many "consumers of plant-based diets could benefit from them," and because "among omnivores, those who do not eat fish or should not consume fish products because of conditions such as allergies to Anysakis, for example, could in turn benefit from their intake, as well as those in the general population who are open to [trying] new formulations, supplements, and functional foods."
How much DHA from microalgae and for how long?
As specified, the results reported by Vaquero and coworkers were obtained by taking 250 mg of DHA from microalgae daily for 5 weeks.
The duration of treatment was not chosen at random: it is, in fact, generally recognized that it takes a few weeks for dietary ingested Omega 3 to incorporate within cell membranes.
What about the dosage? Is it sufficient to hope for health benefits? The Italian Society of Human Nutrition recommends that all adults ensure 250 mg per day of DHA + EPA, and according to the European Food Safety Authority, 250 mg of DHA corresponds to the amount needed to promote good brain function and good vision.
Want to optimize your Omega 3 intake with dietary supplements? Get advice from our pharmacists!
Bibliographic references:
Craddock JC, Neale EP, Probst YC, Peoples GE. Algal supplementation of vegetarian eating patterns improves plasma and serum docosahexaenoic acid concentrations and omega-3 indices: a systematic literature review. J Hum Nutr Diet. 2017 Dec;30(6):693-699. doi: 10.1111/jhn.12474
European Commission. Food and Feed Information Portal Database. Last viewed: 03/02/2025
García-Maldonado E, Alcorta A, Zapatera B, Vaquero MP. Changes in fatty acid levels after consumption of a novel docosahexaenoic supplement from algae: a crossover randomized controlled trial in omnivorous, lacto-ovo vegetarians and vegans. Eur J Nutr. 2023 Jun;62(4):1691-1705. doi: 10.1007/s00394-022-03050-3
Italian Society of Human Nutrition-SINU, 2014. LARN - Reference intake levels for the Italian population: LIPIDS. Last viewed: 03/02/2025
