key: cord-0797369-0eoyxz78
authors: Khetan, Aditya K.
title: COVID-19: Why Declining Biodiversity Puts Us at Greater Risk for Emerging Infectious Diseases, and What We Can Do
date: 2020-06-25
journal: J Gen Intern Med
DOI: 10.1007/s11606-020-05977-x
sha: d040535f676a3a06a9ee1eb3dfa755107c158cca
doc_id: 797369
cord_uid: 0eoyxz78

nan

those viruses. Fruit bats serve as a reservoir for both. With respect to Ebola, the fruit bats thrived among the palm oil trees and, when they came into close contact with humans through these plantations, passed on the virus to humans. For Nipah, the fruit bats contaminated date palm sap, which was then consumed by humans who thus got infected.

Given that loss of biodiversity is a primary driver of EID, there is an urgent need for measures to stem this loss. While public health measures, including surveillance of emerging disease hotspots, can be helpful as near-term strategies, they cannot substitute for a long-term solution that conserves biodiversity. In the absence of this, it is likely that public-health capacity will continue to be overwhelmed. Human activities that drive loss of biodiversity are also directly tied to climate change and increasing water scarcity. As a result, targeting such activities can lead to a multitude of planetary health-and ipso facto human health-benefits. 5 These activities primarily involve agricultural intensification and expansion, which are the primary drivers of deforestation. Human agriculture uses 33% of earth's available land surface, either as cropland (12%) or pasture (21%). It is estimated that between 2000 and 2010, 70% of deforestation was attributable to agricultural land expansion. This agricultural land expansion has mostly been for farming animals (for meat and other animal products such as dairy), soybean production, and palm oil production. 6 Further, over 80% of soybean is used to feed animals for meat and is the principal source of protein for farmed animals. Soybean demand, therefore, is essentially a surrogate for demand of meat. Currently, 40% of calories available from global crop production are either fed to animals or used as biofuels. 5 Given the significant contribution of human meat consumption to loss of biodiversity, decreasing such consumption must be recognized as a major priority for decreasing the incidence of EID over the medium to long term. Such progress will also result in beneficial effects towards combating climate change, reducing water scarcity, and addressing malnutrition. It is estimated that 25% of global GHG emissions are the result of agriculture, most of it from the farming of animals for human consumption. The water footprint of a serving of meat is 10-20 times the water footprint of a serving of plant foods. Decreasing the consumption of meat, therefore, can lead to progress in water conservation. 7 For every gram of protein in beef, 20 g of protein is utilized in feeding the animal. For chickens, the corresponding figure is 4 g. If the world's soybean production were instead utilized to feed humans directly, there would be a several-fold increase in protein availability for a large proportion of humans, whose protein demand is expected to rise with increasing economic prosperity.

It is time we-as an interdependent world-recognize that what we eat primarily determines how the planet is used. Physicians have historically played a leading role in issues that threaten the survival of our species, such as nuclear warfare. But with food, physicians have taken a narrow view in dietary guidelines and focused on isolating the effect of individual foods or nutrients on human health, ignoring the wider ecosystem which our food habits influence, and are, in turn, influenced by. As the latest pandemic shows, such a narrow view has been counterproductive, and likely will continue to cause significant harm. It is time for us to recognize that food, human health, and the environment are deeply interconnected, and understanding these relationships is vital to our planetary health.

Global trends in emerging infectious diseases

Impacts of biodiversity on the emergence and transmission of infectious diseases

Human influences on biodiversity

Evolution in action: climate change, biodiversity dynamics and emerging infectious disease

Safeguarding human health in the Anthropocene epoch: report of The Rockefeller Foundation-Lancet Commission on planetary health

Tropical forests were the primary sources of new agricultural land in the 1980s and 1990s

Country-specific dietary shifts to mitigate climate and water crises