edible insects – good for our health and the planet?
While eating insects is already commonplace in many Asian, African, and Latin American countries, the thought of insect pasta, insect protein bars, or insect condiments and spreads still triggers a ‘yuck’ from most Europeans and North Americans. A 2021 Statista Global Consumer Survey undertaken in Germany found that only around 25% of consumers would consider eating insects. In comparison, 37% of those surveyed would consider eating cell-cultured meat (also known as lab-grown meat), which is another alternative to traditional meat production and, like insects, evokes feelings of disgust in many (meat) eaters.
At the same time, Germans (and other Europeans) are increasingly trying to reduce their daily meat consumption for reasons of environmental protection, health and animal welfare. Although the per capita consumption of meat in Germany is currently above the level recommended by the German Nutrition Society (300-600 g per week), the trend toward meat consumption is decreasing. Many consumers are opting for well-known plant-based substitutes, such as soy and seitan, but the development in the area of meat alternatives is far from complete. Products such as burger patties made from pea protein are increasingly entering the market, and the nutritional and environmental benefits of eating insects are also becoming more widely known.
What is the buzz about eating insects for our health and the planet?
Insects have a composition of macronutrients (protein and fat) characteristic of that of meat and fish. Similar to meat and fish, this composition varies considerably within the individual insect species. The proportion of protein in the dry weight ranges from 40% to 70% in the different edible insect species, and the fat content is usually between 5% and 40% of the dry mass.
How valuable proteins are for human nutritional requirements can be evaluated based on the amino acid composition and the digestibility of the protein. An assessment applying the protein digestibility-corrected amino acid score (PDCAAS) showed that the protein quality of silkworms was high scoring like meat. Earlier studies (using less specialised methods) also found edible insects to be a valuable protein source for human diets, providing for essential and digestible amino acids particularly for those who are following an otherwise mainly plant-dominated diet. A study published in 2022 further assessed the protein quality of five insect species applying the Digestible Indispensable Amino Acid Score (DIAAS) – a newer method than the PDCAAS, suggested to be used since 2011 – and found that, amongst other, two cricket species can be classified as good protein sources for humans.
The fatty acid composition determines the fat quality of food. While different insect species have varying fat qualities, which is further affected by what the insects have been feeding on, overall, it can be said that insects can be valuable sources of essential omega-3 and omega-6 fatty acids. It is essential for us humans to get sufficient amounts of omega-3 and omega-6 acids through our diets, and while the latter are available in a variety of food sources, the former are more scarcely available, particularly in diets with little animal food sources. The field cricket and the Cambodian spider have both been found to be omega-3 rich food sources, being beneficial and comparable to most meat and freshwater fish sources, and only inferior to marine fish.
Another nutritional benefit of edible insects is the fact that they tend to be eaten whole (including head, organs, shell, etc.), contributing to a generally higher content of minerals and vitamins in comparison to animal food sources of which only a portion is considered to be edible. Again, the quality of minerals and vitamins varies widely between the various species, however, insects have generally been found to be valuable sources of minerals such as iron and zinc.
So, insects contain important macro- and micronutrients that are essential for human nutrition, but what about their environmental footprint?
Can we get the same amount of nutrients from eating insects as we can from eating conventional meat (e.g., beef, pork, poultry), but using less agricultural land, energy and water, and emitting less CO2? If so, this would be a great advantage in a world where the global population is growing, requiring more and more food and at the same time increased living space.
The short answer is yes, insects have a smaller ecological footprint than conventional livestock. There are a number of reasons for this. Insects have a higher land use efficiency as they have rapid growth rates, typically reaching sexual maturity within days (rather than months or even years), and high fecundity, potentially producing thousands of offspring. They are also more efficient at converting feed into edible food than conventional livestock, in part because up to 100% of the insect is consumed (compared to cattle, of which only 40% of the live weight is consumed). They are also poikilothermic, meaning they do not use their metabolism for heating or cooling, which reduces energy consumption. This also reduces their water consumption, as they do not rely on evaporation of water to keep their body temperature low. Generally, both the indirect and direct water footprint of insects is low.
Moreover, it’s no secret that conventional livestock farming is not very climate-friendly. Beef production, for instance, emits about 500kg of CO2-eq per kilogram of protein, while mealworm larvae emit only 14kg of CO2-eq.
All in all, to provide the same nutritional value, the production of edible insects uses less agricultural land, energy and water, and produces much less CO2 per kilogram of additional mass than conventional livestock farming.
But we should not forget about plant-based foods!
All food has environmental costs, but some evidently have a larger ecological footprint (e.g., beef) than others (e.g., peas). Insect cultivation falls somewhere in between the two extremes. Pea production, for instance, emits only 4kg of CO2-eq per kilogram of protein (10kg less than mealworm larvae), and tofu requires approximately half of the agricultural land needed for insect cultivation.
So, the environmental benefits of increasing the consumption of edible insects in Europe and North America depend on how we replace them with the foods we currently eat. If we choose to eat a burger made from insects rather than beef at the supermarket or in the restaurant, this could actually have a positive impact on the environment. However, we should not forget about plant-based foods, of which increased consumption can make an important contribution to environmental protection.