Beyond Meat: The Food on Your Plate & Covid-19
It’s not just meat consumption that heightens the risk and impact of diseases like COVIDー19. Vegetarian or not, the fundamental way in which we produce and consume food is destroying our ability to live with nature.
Input-intensive industrial agriculture is a launchpad for infectious diseases in more ways than one. Much attention has focused on the implications of excessive meat consumption which drives habitat loss and enhances human-wildlife interaction. There is also evidence that the overuse of antimicrobials in livestock makes pathogens resistant to drugs used in human & animal medicine.
In the US, 9 times more antibiotics are given to animals than humans. 90% of antibiotic use in animals is non-therapeutic.
Source: Emerging human infectious diseases and the links to global food production, Rohr et al., Nature Sustainability, June 2019
Treating diseases caused by pathogens previously exposed to antibiotics is therefore much more challenging.
“The rise of AMR in zoonotic pathogens, including to last-resort drugs such as colistin, is an important challenge for human medicine because it can lead to untreatable infections.”
Source: Reducing antimicrobial use in food animals, Van Boeckel et al., Science 29 Sep 2017: Vol. 357, Issue 6358, pp. 1350–1352
Whilst excessive meat consumption is a major factor contributing to the spread of infectious diseases, there are other, perhaps less visible but still important ways in which the industrial model of farming poses a major risk to human health.
- Overuse of Insecticides. Resistance to insecticides which suppress both agricultural pests and disease-carrying insect vectors is growing. Several mosquito carriers of human and livestock pathogens are already resistant to common insecticide compounds. Resistance tends to make diseases more virulent and therefore more difficult for humans to treat.
Source: The molecular basis of insecticide resistance in mosquitoes, Hemingway et al., Insect Biochemistry and Molecular Biology, Vol. 34, 2004.
2. Overuse of Pesticides. There is now ample evidence that apart from contributing to non-infectious diseases such as cancers, birth defects, and impaired childhood development, the widespread use of pesticides makes humans more susceptible to parasites by weakening their immune responses. Particularly in developing countries with weak health systems, this effect is detrimental to millions of small-scale farmers.
3. Excessive Consumption of Grains Produced in Monocultures
Out of a possible 6,000–7,000 edible plant species, just 3 (rice, wheat and maize) account for more than 40% of our daily calories. If you include sugar cane, sugar beet, soybeans, potatoes, cassava, and oil-palm fruit, together these 9 plants account for a whopping two-thirds of global crop production.
Source: When too much isn’t enough: Does current food production
meet global nutritional needs? KC et al., PLoS ONE, 13 (10), 2018
Not only is this pattern of production completely at odds with what is recommended for healthy eating, it is also reducing biodiversity within our agricultural systems as these crops are overwhelmingly produced on large-scale monocultures.
Biodiversity is proven to limit the spread of parasites that infect humans via a phenomenon known as the “dilution effect”. This says that in areas where species vary in susceptibility to infection by a pathogen, higher diversity leads to lower infection prevalence in animal and human hosts. In a meta-analysis of over 200 studies on biodiversity and host–parasite systems, scientists found overwhelming evidence of the dilution effect.
“We provide broad evidence that host diversity inhibits parasite abundance using a meta-analysis of 202 effect sizes on 61 parasite species. The magnitude of these effects was independent of host density, study design, and type and specialization of parasites, indicating that dilution was robust across all ecological contexts examined.”
Source: Biodiversity inhibits parasites: Broad evidence for the dilution effect, Civitello et al., PNAS, 2015
Therefore, biodiversity losses — associated with large-scale monoculture could worsen epidemics that harm humans and wildlife.
Managing the complex interactions between agriculture and human health requires a fundamental change in what we eat and how it is produced. That starts with what is on our plate at each and every meal. It might sound far-fetched but buying organically-produced food, eating more diverse meals, and switching from animal to plant-based protein can save lives, make you healthier, and protect the planet.