The demand for meat is expected to grow by about 70% up to 2050. However, the land area used for livestock production is currently 80 percent of total agricultural land use. Increasing yields on existing agricultural land is a possibility, but there are limitations to further intensification of the use of croplands. Other mitigation measures possibilities are to increase the efficiency of the food chain from ‘field to fork”, to increase yield of pastures or to change diets towards food commodities requiring less land. One of the options is to use insects as food and feed.
About 2000 insect species are eaten worldwide, mostly in tropical countries. There is an erroneous western assumption that people in tropical countries eat insects out of necessity. This is because insects have never been considered in the western world as food. In fact, in this part of the world, there is a negative attitude towards insects, which may not be justified considering that only 0.1 percent of the total estimated insect species in the world (5000 out of 5 million) are harmful for plants, humans and animals. Most insects are useful providing essential ecosystem services like pollination, natural control of harmful pest species and waste degradation, and of course they provide products like silk and honey. Representatives from almost all insect groups are eaten such as beetles, caterpillars, wasps, bees, and ants, crickets, grasshoppers, locusts, true bugs, termites, dragonflies, and flies. Up till now most insect species are collected from nature.
Are there nutritional benefits of eating insects? It is difficult to generalize with the 2000 different species. However, compared to conventional meat in general the protein content is similar, while they contain more unsaturated (good) fatty acids. Insects also contain in general more minerals like iron and zinc. This is quite important considering that anaemia affects one-quarter of the world’s population and is concentrated in preschool-aged children and women. Zinc deficiency results in a substantial disease burden, predominantly among children less than 5 years of age, resulting in approximately 453,000 deaths.
Why should we promote the use of insects as food and feed? There are a number of environmental reasons to consider replacing conventional meat by alternative protein sources. Globally, livestock systems contribute to 18% of global anthropogenic greenhouse-gas (GHG) emissions. The main greenhouse gases from livestock systems are methane from animals (25%), carbon dioxide from land use and its changes (32%), and nitrous oxide from manure and slurry (31%). To reduce GHG emissions, a number of mitigation strategies have been proposed such as better quality diets for ruminants, more productive livestock breeds, and changing from cows, sheep and goats to pigs and poultry. But, a change from livestock species to mini-livestock species such as insects has hardly been considered. Another atmospheric pollutant caused by livestock is ammonia (NH3), responsible for about 60 percent of global emissions. The emitted NH3 is returned to the surface by deposition, which is known to be one of the causes of soil acidification, eutrophication of natural ecosystems and loss of biodiversity.
Now the question is whether insects are doing environmentally better than conventional livestock. Studies show that a number of insects species promoted for human consumption such as crickets, mealworms and locusts produce considerable less greenhouse gases and that mealworms produce considerable less ammonia than pigs. A life cycle analyses (that takes into account the whole production process) with mealworms showed that the area needed to produce one kg of protein is 18 square meter, while for cattle it is ten times more. Another environmental benefit is the high feed conversion efficiency. This is the number of kilograms feed needed to produce one kg of edible bodyweight, e.g. for one kg of beef you need 25 kg of feed, while for one kg of edible cricket you need only 2.1 kg. The less needed feed is probably due to the fact that insects are cold-blooded, not needing to maintain a body temperature. There is one other advantage of insects. A number of species can be grown on organic side-streams, in particular important if you consider that one third of all our agricultural produce and food is wasted. They can convert low value organic by-products into high value protein products.
We can also use insects to feed pets, livestock and fish. This is increasingly important as current protein feed ingredients, such as fishmeal, are becoming increasingly expensive. For example, the fish farming (the aquaculture industry) now supplies more than 50 percent of total food fish supply and it is still increasing by about 9% a year. However, fish meal used for carnivorous fish species (e.g. carp, salmon, tilapia and catfish) is becoming limited in supply and therefore expensive. Fishmeal is extracted from wild forage fish, that becomes scarce because of overexploitation of the oceans. Vegetable feedstuffs, such as soya, can be used but the amino acid profile, anti-nutritional factors, low palatability and a high proportion of fibre, limits its inclusion in the diet. Insects appear to be a sustainable source of protein with an appealing quantity and quality and acceptable nutritive properties. Promising insect species are the Black Soldier Fly and the Domesticated House Fly.
The promotion of insects for human consumption and the utilization of insect meals in animal and fish feeding requires the mass production of insects. Experience is available. In Asia silk is produced on a large scale. Companies worldwide produce insects as fish bait and as feed for birds and reptiles. In the West companies, produce beneficial insects and market those to control arthropod pests of agricultural crops. However, feedstock companies that produce for aquaculture and the livestock industry need to be ensured of a large and continuous quantity of standard quality. The cost price of insect products needs to be competitive with currently used protein sources. This is possible by automating the production process. Concerning human consumption, edible insects are in particular farmed in Thailand. About 20,000 medium and large-scale enterprises in this country produce 7,500 tonnes crickets per year; also other species are reared by using simple techniques. In Thailand with increasing welfare, the demand for human consumed insects is on the increase.
Is it safe to eat insects? Livestock and humans are similar, so they can share many diseases. So, new disease strains of livestock may be lethal to humans. However, insects are very different from humans, so we expect this risk to be much lower. The few instances of food safety problems with insects relate to contamination with pathogens. For that reason, insects need to be reared under hygienic conditions. Similar to other animal derived products, insects are susceptible for microbiological hazards and therefore, proper heat treatment or storage conditions are required. Could people allergic to seafood and to house dust mites face problems when eating insects? In laboratory studies it has been demonstrated that cross reactivity is possible and currently tests are being carried out in vivo (with humans) to ascertain this. If proven that this may occur, proper labelling of the insect product is required.
How to get the consumers, in particular the western ones, to eat insects? Even when stressing the environmental, nutritional and food safety aspects, and even when the product has an excellent taste, consumers may not be convinced. In the western world, insects have never been considered food. Cultural acceptance has to deal with emotions and with psychology. However, with globalization it is possible that consumers may adapt as has been shown in the case of sushi.
Insects provide many services to mankind. The benefits of using insects as food and feed over conventional meat are numerous. It has a high potential of becoming a new sector in agriculture and the food and feed industry.
Dr. Arnold van Huis is a tropical entomologist and professor at Wageningen University, the Netherlands