What if you could get the same benefits of eating salmon by simply adding dressing to your salad? You have, after all, probably heard that eating fish is good for you, right?
“Eat fish, lower your risk of deadly heart attack,” reads a recent headline from ABC Radio. That’s because fish oil is rich in omega-3 polyunsaturated fatty acids, the wonder-nutrients that have long been associated with improved cardiovascular health. While that’s great news for pescatarians, what do you do if you’re a vegetarian or vegan? Or if you just don’t like fish?
Researchers at Dow AgroSciences may have a solution by improving canola seeds which is used to make one of the most healthy and widely consumed plant products: canola oil. They reported the development of a canola plant that produces the two long-chain polyunsaturated omega-3 fatty acids found in fish: docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).
These fishy fatty acids have been shown many times to be associated with heart health, including in a recent comprehensive study in the Journal of the American Medical Association Internal Medicine of over 45,000 people. The study showed that several omega-3 fatty acids, including DHA and EPA, led to a lower risk of fatal coronary heart disease.
There are a few reasons why canola is a good crop for producing these two fish-famous fatty acids. First, canola is already a well-established, multibillion dollar crop, mostly grown for its oil-containing seeds. Second, it makes a ‘healthy’ oil. Even as is, canola oil has enough unsaturated fats that it’s allowed to sport the following qualified health claim from the FDA:
Limited and not conclusive scientific evidence suggests that eating about 1 ½ tablespoons (19 grams) of canola oil daily may reduce the risk of coronary heart disease due to the unsaturated fat content in canola oil. …
But canola oil is lacking in omega-3 fatty acids, especially when compared to flaxseed, which has very high levels of the essential omega-3 fatty acid alpha-linolenic acid (ALA).
The new approach seems to solve that deficiency. The authors claim that just 1 tablespoon of the new canola oil processed from field-grown plants has more than the daily recommended amount of omega-3 polyunsaturated fatty acids per serving.
A healthy serving of (micro)algae
Surprisingly, while we get most of our dietary omega-3s by eating fish, fish don’t actually produce the omega-3 fatty acids themselves. Microscopic microalgae, including phytoplankton, are the primary producers of DHA and EPA. The tiny unicellular organisms are consumed up the food chain, with their nutrients eventually accumulating in the fatty tissues of the fish.
The Dow scientists took the genetic assembly line for omega-3 fatty acids from microalgae and put it into canola. They designed the system to turn on only in the canola seeds, where the oil is produced and stored, by using seed-specific promoters to activate the genes. This certainly isn’t the first time plants have been used to produce omega-3s, but there is a unique aspect to this approach.
Reached for a comment, Dow AgroSciences told the GLP that this work represents the first time that such a ‘megasynthase,’ the complex set of proteins for, in this case, fatty acid production has been successfully expressed in a crop plant. “The ability to express these large complex genes in plants and have them function to produce omega-3 fatty acids is truly a remarkable technical accomplishment,” said Dan Kittle, Vice President of Research and Development.
In a statement to the Genetic Experts News Service (GENeS), Kan Wang, director of the Center for Plant Transformation at Iowa State University who was not involved with this study but has worked on crop genetics with Dow AgroSciences previously, emphasized that this isn’t the first time oilseeds have been used to make DHA and EPA, but noted this new approach:
They introduced a large microalgae biosynthetic system that includes multiple proteins and enzymes into canola. This approach allows the engineered seeds to produce additional fatty acids instead of just converting existing fatty acids into polyunsaturated fatty acids, a strategy used in earlier efforts.
So rather than requiring stores of existing fatty acids and converting them into DHA and EPA through a multi-step process, they can essentially be made in a single step, which has its advantages according to Wang:
Another advantage of this strategy is that it does not accumulate other intermediate fatty acids. Those intermediate fatty acids can increase oxidative instability of the oil and often are the culprit of off-flavors for oil products.
While these new canola plants may or may not end up being vegetarians’ go-to source of omega-3 fatty acids—regulatory and political hurdles aside—they do represent an example of plants as a vehicle for manufacturing nutrients or goods with tangible benefits.
Not only could they have potential health benefits for humans, but producing omega-3 enriched plant-based oils could also ease the burden on fish farming and the demand for fish oil for the fish farms. In a bit of a wasteful feedback loop, farmed fish have to be fed fish oil in order to accumulate the fatty acids that they would otherwise obtain from microalgae.
In addition to using plants to produce nutrients, there is the growing field of biopharmaceuticals, particularly the development of plant-based vaccines for a number of viruses including ebola, polio, and the flu. Plant-based vaccines can provide a more affordable and more immediate model to develop and deliver antibody treatments.
Taken together, these solutions show some of the improvements that scientists have made in taking advantage of plants as photosynthetic production lines. For plant-based fish oils, it remains to be seen whether they will provide similar nutritional benefits as consuming fish, but for many they may offer hope of a healthy, fish-free alternative.