Ok, so this one’s a little outside the box as far as superfoods go. Krill are toothpick-sized, shrimplike crustaceans found in all the world’s oceans: and they are plentiful. One species (Antarctic krill) in just the Southern Ocean has a biomass of over 500 million tons, or about twice that of humans the world over. (Krill have the largest animal biomass on the planet.) Krill cannot be farmed, only caught in the wild. About 200,000 tons per year come out of the Scotia Sea around Antarctica. The world’s northern seas are estimated to also have 500 million tons: about 110,000 tons are harvested annually.
Krill are a nearly endless protein source, given their huge numbers and short lifespan. They are a dietary staple of whales, seals, penguins, squid, and fish, and that includes the mighty (and mighty large) blue whale. Weighing in at around 240,000 pounds with a heart the size of a Volkswagen, the blue whale eats up to 40 million krill a day to keep the ol’ tummy full.
Krill are low in fat, extremely high in protein, chock full of omega-3s (including DHA and EPA), plus they have astaxanthin, a powerful antioxidant. Fish in the salmon family have a small amount of astaxanthin (it’s what makes their flesh pink), but krill have it in much greater concentrations.
The health benefits of omega-3s are pretty well-known by now (they reduce inflammation, lower triglycerides, lower heart disease risk, reduce joint stiffness and pain for those with rheumatoid arthritis, and fight depression), but astaxanthin has not been studied to the same degree. Animal studies suggest that it helps protect cells and boost immunity, lowers blood pressure, and increases insulin sensitivity. Researchers have found that in humans astaxanthin protects from sun damage, helps with stress management and muscle function, and also helps prevent neurodegenerative diseases like Parkinson’s and Alzheimer’s.
Research indicates that the omega-3 in krill oil is more bioavailable than that in fish. Michael Eades, MD, writes, “In fish oil, these omega-3 fatty acids are found in triglyceride form, whereas in krill oil they are hooked up in a double chain phospholipid structure. The fats in our own cells walls are in the phospholipid form … The antioxidant potency of krill oil is such that when compared to fish oil in terms of ORAC (Oxygen Radical Absorbance Capacity) values, it was found to be 48 times more potent than fish oil.”
And if that wasn’t enough, eating krill works around one of the main concerns with seafood, namely, mercury. The mercury risk gets more severe the higher up the food chain you go: whereas swordfish and sharks have mercury levels of about one ppm, shrimp have .001 and krill, being substantially smaller than shrimp would have even less.
How to Eat it
Whales seem to have a massive taste for raw krill (as do penguins) but we’ve never really looked to them for culinary input. Most people find the taste of krill, well, nonexistent. This isn’t entirely bad. Krill are eaten in Russia, Japan, and Korea as dried snacks, pizza toppings, and salad components. (And there’s a San Francisco area coffee shop that serves krill as food, but that’s the only known eating establishment in the US to do so. San Franciscans are famously openminded about food, which is maybe why they can pull it off.)
Most krill consumed in the US comes in the form of krill oil supplements, which are an excellent alternative to fish oil. Due to the molecular structure, krill oil naturally takes longer to break down, making it easier to work with and more likely that you won’t get a bad batch. And the risk of mercury contamination is virtually nonexistent.
There are, of course, sustainability concerns with many commercial fisheries, and part of the remedy for that sort of problem is to eat lower on the trophic level. The lower you go on the trophic level, the more plentiful and faster growing the resource is. There are those who have expressed concern about overfishing krill, but it seems we’re a long way from that. The Commission for the Conservation of Antarctic Marine Living Resources (with the tongue twisting acronym CCAMLR) has put a cap on the harvest at five million tons, of which we harvest a small fraction. At this point, there’s no reason to worry about the global supply.
Whether you take krill as supplements or are on the leading edge of culinary culture and actually eat them whole, try some out. They’ll do you good.