For the first time, a study has measured antioxidant levels in commercially available edible insects. For open-minded health freaks, it's good news. Crickets pack 75% the antioxidant power of fresh OJ, and silkworm fat twice that of olive oil.
Also, insects have a tiny land, water and carbon footprint compared with livestock—so anything that encourages insect eating is good news for the planet, too.
"At least 2 billion people -a quarter of the world's population- regularly eat insects," says Prof. Mauro Serafini, lead author of the study published in Frontiers in Nutrition. "The rest of us will need a bit more encouragement."
Providing selfish and immediate incentives could help consumers to make the environmentally friendly choice, says Serafini. Taste and image are key - but for many, health is also an incentive: "Edible insects are an excellent source of protein, polyunsaturated fatty acids, minerals, vitamins and fiber. But until now, nobody had compared them with classical functional foods such as olive oil or orange juice in terms of antioxidant activity."
Antioxidant activity is that free-radical scavenging ability that typically designates a 'super food' - although this poorly defined term is eschewed by researchers, says Serafini.
The researchers tested a range of commercially available edible insects and invertebrates, using various measures of antioxidant activity. Inedible parts like wings and stings were removed, then the insects were ground and two parts extracted for each species: the fat, and whatever would dissolve in water. Each extract was then tested for its antioxidant content and activity.
"For perspective, using the same setup we tested the antioxidant capacity of fresh orange juice and olive oil—functional foods that are known to exert antioxidant effects in humans," Serafini explains.
Water-soluble extracts of grasshoppers, silkworms and crickets displayed the highest values of antioxidant capacity—fivefold higher than fresh orange juice—while giant cicada, giant water bugs, black tarantula and black scorpions showed negligible values.
Note that these comparisons are for the dry, fat-free insect dust—a tad tougher to swallow than fresh OJ. Even so, some quick math shows that at the same dilution (88% water), grasshoppers and silkworms would have about 75% the antioxidant activity of OJ.
Interestingly, the total content of polyphenols—the major source of plant-derived antioxidant activity—followed a similar pattern across species, but was far lower in all insects compared to OJ.
"These results suggest that besides polyphenols, the antioxidant capacity of insects also depends on other, as yet unknown compounds," Serafini adds.