Why Eat Crickets? A U.N Report
Food And AgrIculture organIsatIon of the UnIted NatIons Report - A summary
Cricket's on the Road in Vietnam
UN REPORT ON INSECTS AS FOOD 2013
It is widely accepted that by 2050 the world will host 9 billion people. To accommodate this number, current food production will need to almost double. Land is scarce and expanding the area devoted to farming is rarely a viable or sustainable option. Oceans are overfished and climate change and related water shortages could have profound implications for food production. To meet the food and nutrition challenges of today – there are nearly 1 billion chronically hungry people worldwide – and tomorrow, what we eat and how we produce it needs to be re-evaluated. Inefficiencies need to be rectified and food waste reduced. We need to find new ways of growing food.
Edible insects have always been a part of human diets, but in some societies, there is a degree of distaste for their consumption. Although the majority of edible insects are gathered from forest habitats, innovation in mass-rearing systems has begun in many countries. Insects offer a significant opportunity to merge traditional knowledge and modern science in both developed and developing countries.
“Why Eat Insects?
Health: - Insects are healthy, nutritious alternatives to mainstream staples such as chicken, pork, beef and even fish.
Many insects are rich in protein and good fats and high in calcium, iron and zinc.
Insects already form a traditional part of many regional and national diets.”
Environmental Opportunities
The environmental benefits of rearing insects for food and feed are founded on the high feed conversion efficiency of insects. Crickets, for example, require only 2 kilograms of feed for every 1 kilogram of bodyweight gain. In addition, insects can be reared on organic side-streams (including human and animal waste) and can help reduce environmental contamination. Insects are reported to emit fewer greenhouse gases and less ammonia than cattle or pigs, and they require significantly less land and water than cattle rearing. Compared with mammals and birds, insects may also pose less risk of transmitting zoonotic infections to humans, livestock and wildlife, although this topic requires further research.
Nutrition for human consumption
Insects are a highly nutritious and healthy food source with high fat, protein, vitamin, fibre and mineral content. The nutritional value of edible insects is highly variable because of the wide range of edible insect species. Even within the same group of species, nutritional value may differ depending on the metamorphic stage of the insect, the habitat in which it lives, and its diet. For example, the composition of un sat omega 3 and 6 fatty acids in mealworms is comparable with that in fish (and higher than in cattle and pigs), and the protein, vitamin and mineral content of mealworms is similar to that in fish and meat.
Why Eat Insects?
Overall, entomophagy can be promoted for three reasons:
- Health: - Insects are healthy, nutritious alternatives to mainstream staples such as chicken, pork, beef and even fish (from ocean catch).
- Many insects are rich in protein and good fats and high in calcium, iron and zinc.
- Insects already form a traditional part of many regional and national diets.
Environmental
Insects promote as food emit considerably fewer greenhouse gases (GHGs) than most livestock (methane, for instance, is produced by only a few insect groups, such as termites and cockroaches). - Insect rearing is not necessarily a land-based activity and does not require land clearing to expand production. Feed is the major requirement for land. - The ammonia emissions associated with insect rearing are also far lower than those linked to conventional livestock, such as pigs. - Because they are cold-blooded, insects are very efficient at converting feed into protein (crickets, for example, need 12 times less feed than cattle, four times less feed than sheep, and half as much feed as pigs and broiler chickens to produce the same amount of protein). - Insects can be fed on organic waste streams.
Benefits to nature
Insects deliver a host of ecological services fundamental to the survival of humankind. For instance, insects play an important role in plant reproduction. An estimated 100 000 pollinator species have been identified and almost all of these (98 percent) are insects (Ingram, Nabhan and Buchmann, 1996). Over 90 percent of the 250 000 flowering plant species depend on pollinators. This is also true for three-quarters of the 100 crop species that generate most of the world’s food (Ingram, Nabhan and Buchmann, 1996). Domesticated bees alone pollinate an estimated 15 percent of these species. The importance of this ecological service for agriculture and nature more generally is undisputed.
Environmental opportunities for insect rearing for food and feed
Feeding a growing world population with more demanding consumers will necessarily require an increase in food production. This will inevitably place heavy pressure on already limited resources such as land, oceans, fertilisers, water and energy. If agricultural production remains in its present form, increases in GHG emissions, as well as deforestation and environmental degradation, are set to continue. These environmental problems, particularly those associated with raising livestock, need urgent attention.
Livestock and fish are important sources of protein in most countries. According to FAO (2006), livestock production accounts for 70 percent of all agricultural land use. With global demand for livestock products expected to more than double between 2000 and 2050 (from 229 million tonnes to 465 million tonnes), meeting this demand will require innovative solutions. Similarly, fish production and consumption has increased dramatically in the last five decades. As a consequence, the aquaculture sector has boomed and now accounts for nearly 50 percent of world fish production. The sustainable growth of the sector will depend largely on the supply of terrestrial and aquatic plant-based proteins for feed. The opportunity for insects to help meet rising demand in meat products and replace fishmeal and fish oil is enormous.
Large-scale livestock and fish production facilities are economically viable because of their high productivity, at least in the short term. However, these facilities incur huge environmental costs (Tilman et al., 2002; Fiala, 2008).
Manure, for example, contaminates surface water and groundwater with nutrients, toxins (heavy metals) and pathogens (Tilman et al., 2002; Thorne, 2007). Storing and spreading manure can involve the emission of large quantities of ammonia, which has an acidifying effect on ecosystems. Any increase in animal production will, moreover, require additional feed and cropland and will likely trigger deforestation. The Amazon is a case in point: pasture now accounts for 70 percent of previously forested land, with feed crops covering a large part of the remainder (Steinfeld et al., 2006).
In 2010, Sachs (2010) argued that agriculture was the leading cause of anthropogenic- induced climate change and that the world needed new agricultural technologies and patterns of food consumption based on healthier and more sustainable diets. Feeding future populations will require the development of alternative sources of protein, such as cultured meat, seaweed, beans, fungi and insects.
Consuming insects has a number of advantages:
They have high feed-conversion efficiency (an animal’s capacity to convert feed mass into increased body mass, represented as kg of feed per kg of weight gain). They can be reared on organic side streams, reducing environmental contamination, while adding value to waste.
They emit relatively few GHGs and relatively little ammonia.
They require significantly less water than cattle rearing.
They have few animal welfare issues, although the extent to which insect’s experience pain is largely unknown.
They pose a low risk of transmitting zoonotic infections.
Despite these benefits, consumer acceptance remains one of the largest barriers to the adoption of insects as viable sources of protein in many Western countries. Nevertheless, history has shown that dietary patterns change quickly, particularly in a globalised world (the rapid acceptance of raw fish in the form of sushi being a good example).
As demand for meat rises, so too does the need for grain and protein feeds. This is because far more plant protein is needed for an equivalent amount of animal protein. Pimentel and Pimentel (2003) calculated that for 1 kg of high-quality animal protein, livestock are fed about 6 kg of plant protein. Feed-to-meat conversion rates (how much feed is needed to produce a 1 kg increase in weight) vary widely depending on the class of the animal and the production practices used. Typically, 1 kg of live animal weight in a typical United States production system requires the following amount of feed: 2.5 kg for chicken, 5 kg for pork and 10 kg for beef (Smil, 2002). Insects require far less feed. For example, the production of 1 kg of live animal weight of crickets requires as little as 1.7 kg of feed (Collavo et al., 2005). When these figures are adjusted for edible weight (usually the entire animal cannot be eaten), the advantage of eating insects becomes even greater (van Huis, 2013). Nakagaki and DeFoliart (1991) estimated that up to 80 percent of a cricket is edible and digestible compared with 55 percent for chicken and pigs and 40 percent for cattle. This means that crickets are twice as efficient in converting feed to meat as chicken, at least four times more efficient than pigs, and 12 times more efficient than cattle (see Figure 5.1). This is likely because insects are cold-blooded and do not require feed to maintain body temperature.
Nutritional values
Proteins and amino acids (“food chemistry”)
Proteins are organic compounds consisting of amino acids. They are important elements of food nutrition but also contribute to its physical and sensory properties. The nutritive value depends on several factors: protein content, which varies widely among all foods; protein quality, which depends on the kind of amino acids present (essential or non- protein digestibility, which refers to the digestibility of the amino acids present in the food.
Amino acids through human metabolism to ensure proper growth, development and maintenance.
Essential amino acids are indispensable because the body cannot synthesise them and so must obtain them through food. Eight amino acids are classified as essential: phenylalanine, valine, threonine, tryptophan, isoleucine, methionine, leucine and lysine.
Amino acids
Cereal proteins that are key staples in diets around the world are often low in lysine and, in some cases, lack the amino acids tryptophan (e.g. maize) and threonine. In some insect species, these amino acids are very well represented (Bukkens, 2005). For example, several caterpillars of the Saturniidae family, palm weevil larvae and aquatic insects have amino acid scores for lysine higher than 100 mg amino acid per 100 g crude protein.
Fatty acids
Saturated fatty acids. In general, saturated fatty acids have a higher melting point than unsaturated fatty acids and are solid at room temperature. They are often found in animal products and tropical oils (e.g. palm and coconut oil).
Unsaturated fatty acids. These consist of mono-unsaturated fatty acids and fats consist of at least one double bond, and yield slightly less energy during metabolism. They are mostly present in vegetable oils, nuts and seafood. Unsaturated fatty acids are considered better for human health than saturated fat.
Essential fatty acids. These cannot be synthesised by the human body, which means that they must be obtained from the diet. They include some omega-3 fatty acids (e.g. α-linolenic acid) and some omega-6 fatty acids (e.g. linoleic acid).
Micronutrients
Micronutrients – including minerals and vitamins – play an important role in the
nutritional value of food. Micronutrient deficiencies, which are commonplace in many developing countries, can have major adverse health consequences, contributing to impairments in growth, immune function, mental and physical development and reproductive outcomes that cannot always be reversed by nutrition interventions (FAO, 2011c). In insects, metamorphic stage and diet highly influence nutritional value, making all-encompassing statements on the micronutrient content of insect species of little value. Moreover, the mineral and vitamin contents of edible insects described in the literature are highly variable across species and orders. Consumption of the entire insect body generally elevates nutritional content. A study on small fish, for example, suggested that consuming the whole organism – including all tissues – is a better source of minerals and vitamins than the consumption of fish fillets. In much the same way, consuming the entire insect is expected to provide higher micronutrient content than eating individual insect parts (N. Roos, personal communication, 2012).
Minerals
Minerals play an important part in biological processes. The recommended dietary allowance (RDA) and adequate intake are generally used to quantify suggested daily intake of minerals. Most edible insects boast equal or higher iron contents than beef (Bukkens, 2005). Beef has an iron content of 6 mg per 100 g of dry weight.
Edible insects are undeniably rich sources of iron and their inclusion in the daily diet could improve iron status and help prevent anaemia in developing countries. WHO has flagged iron deficiency as the world’s most common and widespread nutritional disorder. In developing countries, one in two pregnant women and about 40 percent of preschool children are believed to be anaemic. Health consequences include poor pregnancy outcomes, impaired physical and cognitive development, increased risk of morbidity in children and reduced work productivity in adults. Anaemia is a preventable deficiency but contributes to 20 percent of all maternal deaths. Given the high iron content of several insect species, further evaluation of more edible insect species is warranted (FAO/WHO, 2001b).
Zinc deficiency is another core public health problem, especially for child and maternal health. Zinc deficiencies can lead to growth retardation, delayed sexual and bone maturation, skin lesions, diarrhoea, alopecia, impaired appetite and increased susceptibility to infections mediated via defects in the immune system (FAO/WHO, 2001b). In general, most insects are believed to be good sources of zinc. Beef averages 12.5 mg per 100 g of dry weight, while the palm weevil larvae (Rhynchophorus phoenicis), for example, contains 26.5 mg per 100 g (Bukkens, 2005).
Vitamins
Vitamins essential for stimulating metabolic processes and enhancing immune system functions are present in most edible insects. Bukkens (2005) showed for a whole range of insects that thiamine (also known as vitamin B1, an essential vitamin that acts principally as a co-enzyme to metabolize carbohydrate into energy) ranged from 0.1 mg to 4 mg per 100 g of dry matter. Riboflavin (also known as vitamin B2, whose principle function is metabolism) ranged from 0.11 to 8.9 mg per 100 mg. By comparison, wholemeal bread provides 0.16 mg and 0.19 mg per 100 g of B1 and B2, respectively. Vitamin B12 occurs only in food of animal origin and is well represented in mealworm larvae, Tenebrio molitor (0.47 μg per 100 g) and house crickets, Acheta domesticus (5.4 μg per 100 g in adults and 8.7 μg per 100 g in nymphs).
Fiber content
Insects contain significant amounts of fibre, as measured by crude fibre, acid detergent fibre and neutral detergent fibre. The most common form of fibre in insects is chitin, an insoluble fibre derived from the exoskeleton. A significant amount of data is available on the fibre content of insects, but it has been produced by various methods and is not easily comparable (H. Klunder, personal communication, 2012). Finke (2007) estimated the chitin content of insect species raised commercially as food for insectivores, and found it to range from 2.7 mg to 49.8 mg per kg (fresh) and from 11.6 mg to 137.2 mg per kg (dry matter).
Chitin, the main component of the exoskeleton of an insect, is a long-chain polymer of N-acetyl glucosamine – a derivative of glucose. Chitin is much like the polysaccharide cellulose found in plants, which is largely believed to be indigestible by humans, although chitinase has been found in human gastric juices (Paoletti et al., 2007). Chitin has also been associated with defence against parasitic infections and some allergic conditions. The above study,
activity in Western countries due to the absence of chitin in the diet. Some argue that chitin acts like a dietetic fibre (Muzzarelli et al., 2001), and this could imply a high-fibre content in edible insects, especially species with hard exoskeletons (Bukkens, 2005).
Effects on human health:
There is very little doubt that entomophagy can be an important solution in decreasing malnutrition in developing countries, but it may also help to improve health in Western societies. As insects are high in mono- and poly-unsaturated fatty acids, intake of insect products instead of conventional livestock products may have positive health effects.
Iron deficiency is the world’s most common nutritional disorder, according to the World Health Organisation (WHO). This condition not only occurs in developing countries but also in Western societies, e.g. in Sweden, 45% of adolescent girls are at risk of iron deficiency (Sjöberg and Hulthén, 2015). Many insects have a high iron content (Bukkens, 1997; Bukkens, 2005; Oonincx et al., 2011), even higher than red meat (FAO, 2013), and entomophagy could therefore be recommended from that perspective. If red meat consumption is reduced in the future, as recommended by the Swedish National Food Administration (Livsmedelsverket, 2015), iron deficiency could become even more common than it is now unless appropriate substitutes are used.