Lovely Grub: Are Insects the Future of Food?
Whether they’re used in animal feed or human food, insects present a slew of hazards. Bugs scooped up from the wild may be covered in pesticides or other contaminants, but even raising insects in industrial, indoor facilities won’t necessarily eliminate the risks. One of the benefits of insects is that they can be raised on waste, but food scraps may be contaminated with fungus, some species of which produce nasty toxins. Animal manure may contain disease-causing bacteria, such as Salmonella and Campylobacter, as well as antibiotics or other drugs given to livestock. Heavy metals such as arsenic, cadmium, and lead can also accumulate in animal manure and agricultural waste – and then in the bodies of insects that feed on it. “We know in some cases insects will tolerate much higher levels of metals than mammals,” Charlton warns. “And therefore, that’s a risk in terms of using them as a feedstock.”
In his initial tests, Charlton found that some flies raised on animal and food waste have cadmium levels higher than limits set by the EU. Other researchers have also documented elevated levels of lead in dried grasshoppers from Mexico and dangerous levels of fungal toxins in the mopane caterpillar, which is eaten in many parts of Africa. “This is not all speculation,” says Charlton.
Insects also have their own pathogens: viruses, bacteria, and fungi that colonize their tiny bodies. Although there’s still a lot to learn about these microorganisms, some could potentially pose risks to humans or livestock.
Then there’s the allergy question. Insects are arthropods, and several other arthropods – most notably shrimp – can cause severe allergic reactions. One of the major triggers of shellfish allergies is a muscle protein called tropomyosin. The protein sequence of tropomyosin is similar in insects and crustaceans, and people with shellfish allergies may also react to insects.
That’s not to say that all these potential dangers will turn out to be actual dangers or that they’re insurmountable. But right now, there’s very little data. “We need to know a lot more, really – that’s the bottom line,” says Charlton.