Six-legged superfoods: Grasshoppers fly to top of insect antioxidant-rich list

15 Jul 2019 --- For the first time, a study has measured antioxidant levels in commercially available edible insects, noting that grasshoppers, silkworms and crickets displayed the highest values of antioxidant capacity – fivefold higher than fresh orange juice. The results may prove promising as insects are being increasingly considered as sustainable alternatives to meat and animal products. However, persuading Western consumers to add “creepy crawlies” to their diet could be simpler if a strong health benefit can be demonstrated.

“At least two billion people – a quarter of the world’s population – regularly eat insects,” says Professor Mauro Serafini, lead author of the study published in Frontiers in Nutrition. “The rest of us will need a bit more encouragement.”

Providing immediate incentives could help consumers to make the environmentally friendly choice, says Serafini. Taste and image are essential – but for many, health is also an incentive.

At least two billion people – a quarter of the world’s population – regularly eat insects.“Edible insects are an excellent source of protein, polyunsaturated fatty acids, minerals, vitamins and fiber. 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 a free-radical-scavenging ability that typically designates a “superfood,” although this poorly defined term is eschewed by researchers, says Serafini.

A 2018 study also found that consuming crickets can help support the growth of beneficial gut bacteria, and that eating crickets is both safe at high doses as well as possibly reducing inflammation in the body.

The first insect antioxidant rankings
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 tested for its antioxidant content and activity.

“For perspective, we used the same setup to test the antioxidant capacity of fresh orange juice and olive oil – functional foods that are known to exert antioxidant effects in humans,” Serafini explains.

The researchers found that vegetarian insects had markedly high antioxidant capacity, with grasshoppers, silkworms and crickets leading the pack, while giant cicadas, giant water bugs, black tarantulas and black scorpions showed negligible values.

Bioavailability
The group’s key message is that edible insects like grasshoppers and silkworms are a rich source of antioxidants.

“A high content of antioxidant in the food matrix is a primary requisite for a first screening of antioxidant potential of novel foods, so these are promising results.”

But the question remains: What are these antioxidants, and do they work in humans?

“The in vivo efficiency of antioxidant-rich food is highly dependent on bioavailability and the presence of ongoing oxidative stress. As well as identifying other antioxidant compounds in insects, we need tailored intervention studies to clarify their antioxidant effects in humans,” she explains.

“In the future, we might also adapt dietary regimens for insect rearing in order to increase their antioxidant content for animal or human consumption.”

Insects: Coming to a plate near you?
While there is a growing interest in edible insects in Western countries, the infrastructure to supply the new ingredients is not yet in place, according to a recent study. 

Lead author Dr. Guiomar Melgar-Lalanne, University of Veracruz, noted that “if edible insects are to become a common food source, current farming techniques and technologies could struggle with the demand and need to be expanded.”

The study also noted that aside from production issues, overcoming social boundaries is another major obstacle to widespread insect consumption. In Western countries, eating insects is considered unusual and many people find the concept unappealing.

Edited by Laxmi Haigh