That means looking beyond the finished supplement. Alternative ingredients could reduce aquaculture’s reliance on fish oil, while algae and other microbial sources offer additional routes to EPA and DHA.
At the same time, emerging research is raising new questions about how much plant-derived omega-3 precursors may contribute to long-chain omega-3 status.
Those threads came together at the Regenerate Symposium in Halifax earlier this month, where presenters Dr. Rinat Ran-Ressler, R&D expert in Lipid Science at Nestlé, Dr. Chris Parrish, University Research Professor in the Department of Ocean Sciences at Memorial University of Newfoundland, and Dr. Richard Bazinet, Professor and Canada Research Chair in Brain Lipid Metabolism at the University of Toronto, approached the omega-3 gap from different points along the supply chain.
The omega-3 gap
Dr. Ran-Ressler opened the symposium by highlighting the disconnect between apparent adequacy of alpha-linolenic acid (ALA) intake and the broader omega-3 picture.
While average ALA intake in the United States appears to meet adequate intake levels, she noted that consumption of linoleic acid (LA), an essential omega-6 fatty acid, is considerably higher. Because LA and ALA compete for enzymes involved in conversion, Ressler said simply looking at ALA intake does not tell the whole story.
She also cautioned against demonizing LA, noting that it is an essential fatty acid with health benefits.
“What we really need to do is to increase our omega-3 intake in order to correct the balance,” she said.
The shortfall is more apparent for the long-chain omega-3s. Dr. Ran-Ressler cited average EPA and DHA intake of approximately 110 mg per day, compared with a commonly recommended minimum of 250 mg per day.
At the same time, she pointed to pressure on traditional marine sources from climate change, overfishing, pollution and contaminants, along with potential impacts on costs and availability.
These factors have put more attention on plant-based sources, which Dr. Ran-Ressler said offer potential advantages around cost, supply, sustainability and formulation, but their potential also hinges on a long-running question about how efficiently the body converts plant-derived omega-3s into EPA and DHA.
During the Q&A discussion following her presentation, Dr. Ran-Ressler said demonstrating that ALA can deliver EPA and DHA would be “huge for the industry” because plant oils are easier to handle.
“But we need to show it,” she added.
Beyond fish oil
Dr. Parrish, a professor at Memorial University of Newfoundland, looked at the problem from the supply side, tracking EPA and DHA through the marine food system, fisheries, processing and aquaculture.
His research points to substantial losses along that chain and limited room to simply extract more omega-3s from existing fisheries.
“What I like here is that we can see that there are many different suppliers of omega-3s of different kinds, and I know that that’s something that we’ve got to do,” he told NutraIngredients. “We’ve got to get beyond fish oil.”
Aquaculture is one area where alternative ingredients could have an outsized impact.
“One of the things that we’re really concerned about is the amount of fish meal and fish oil that’s going into aquaculture,” Parrish said.
His research has explored alternatives including Camelina plants, microbial oils, algae and ingredients recovered from seafood processing.
Some fish can also produce long-chain omega-3s from shorter-chain precursors, although Dr. Parrish noted that this varies by species. Salmon and trout, for example, have greater conversion capacity than cod.
“When I see other suppliers of omega-3 fatty acids that can get into aquaculture so we can get rid of the fish oil and fish meal component of aquaculture, I think that’s going to be a tremendous advancement for all of us,” he said.
It will likely take more than one alternative.
“We’ve got to use algae, we’ve got to use everything except for the traditional fish oil and fish meal in order to close this gap,” Parrish noted during his presentation.
Rethinking omega-3 conversion
Dr. Richard Bazinet focused on another piece of the equation: whether the contribution of plant-based omega-3s has been underestimated.
“The field, for whatever reason, has said there’s an extremely limited synthesis of these molecules, or there’s no synthesis or whatever,” he told NI. “What our research is suggesting is that’s overstated, oversimplified.”
Conventional estimates have generally suggested that only a small percentage of dietary ALA converts to DHA. Bazinet argues that part of the problem may be how researchers have traditionally measured that conversion.
Many studies administer labeled ALA and then measure how much labeled DHA appears in the blood. According to Dr. Bazinet, in animal experiments designed to mimic that approach, the method produced an apparent synthesis rate of around 0.1%, even when other methods indicated greater synthesis.
“The blood’s not a good readout,” he said.
Instead of focusing only on the percentage converted, Dr. Bazinet suggests that researchers should also consider how much DHA a tissue actually needs, framing it as “the idea of how much you have versus how much you need.”
The adult brain, for example, contains several grams of DHA, but Bazinet cited research estimating that it takes up only around 3.8 mg per day. That raises the possibility that a relatively small amount of synthesis could still contribute meaningfully to daily turnover.
His team has also tested plant-derived precursors including ALA from flaxseed and stearidonic acid (SDA) from ahiflower in preclinical research.
In the animal study, Dr. Bazinet said ahiflower accounted for about 75% of DHA turnover relative to the reference group, depending on the tissue, compared with about 50% for flaxseed.
“It’s not as big as DHA directly, but it can take some of that gap out of there,” he said.
The work does not show that plant-derived precursors are equivalent to consuming DHA directly, and Dr. Bazinet stressed that the findings still need to be tested in humans.
“You’ll never be able to synthesize as much DHA as if you consume it, but getting a better understanding of what the actual numbers are, I think that’ll put us in a better place to do studies and test hypotheses,” he said.
His team has received funding from the Canadian Institutes of Health Research for a human study using isotopic signatures to investigate the question further.
More sources, better measurements
For industry stakeholders expanding the omega-3 supply will likely mean drawing from more sources, whether through alternative aquaculture inputs, algae and microbial oils or plant-based precursors.
How much those plant-based sources can ultimately contribute remains an open question.
Dr. Bazinet said better measurements and clearer definitions of omega-3 requirements will be important in answering it.
“I think we need to think about readouts, or frameworks, or ways to answer questions that can drive us towards a more foundational view of what a requirement is,” he said.
His upcoming human study could help clarify how much ALA contributes to DHA synthesis and whether current estimates have been selling that contribution short.
Until then, Dr. Bazinet said the point is not that plant-based omega-3s can replace DHA but that researchers may need to rethink how their contribution is measured.