Well-preserved Amazon rainforest on Indigenous lands can protect people
from diseases, study finds
[September 12, 2025]
By MELINA WALLING
Every time humans cut into the Amazon rainforest or burn or destroy
parts of it, they're making people sick.
It's an idea Indigenous people have lived by for thousands of years. Now
a new study in the journal Communications Earth & Environment adds to
the scientific evidence supporting it, by finding that instances of
several diseases were lowered in areas where forest was set aside for
Indigenous peoples who maintained it well.
With the United Nations climate summit set for Brazil in November, the
study authors and outside experts said the work highlights the stakes
for people around the world as negotiators try to address climate
change. Belem, the city hosting the conference, is known as the gateway
to the Amazon, and many who will be attending, from activists to
delegates, think the role of Indigenous communities in climate action
and conservation will be highlighted in a distinct way.
“The ‘forest man’ or ‘man forest,’ according to the Indigenous
perspective, has always been linked to the reciprocity between human
health and the natural environment where one lives,” said Francisco
Hernández Cayetano, president of the Federation of Ticuna and Yagua
Communities of the Lower Amazon, or FECOTYBA, in the Peruvian Amazon.
“If each state does not guarantee the rights and territories of
Indigenous peoples, we would inevitably be harming their health, their
lives, and the ecosystem itself.”
That harm can look like respiratory diseases such as asthma caused by
toxic air pollution after fires, or illnesses that spread from animals
to humans such as malaria, said Paula Prist, a senior program
coordinator for the Forest and Grasslands Unit at the International
Union for Conservation of Nature and one of the study authors.
The researchers compiled and analyzed data on forest quality, legal
recognition of Indigenous territory and disease incidence in the
countries that border and include the Amazon.
Outside experts weigh in
The work was “impressive” to University of Washington health and climate
scientist Kristie Ebi. She said it highlighted the complexity of factors
that affect human health, and the importance of understanding the role
Indigenous communities play in shaping it. “Using these methods, others
could study other parts of the world,” she said.
The researchers found creative ways to account for other variables that
can affect the spread of diseases, like access to health care in a given
area, said Magdalena Hurtado, an anthropology and global health
professor at Arizona State University and a fellow of the American
Academy of Arts and Sciences who was not involved with the study. But
she expressed concern that the findings were presented with a precision
that may not be warranted, given that they were based on correlation and
use data on observations that can be difficult to measure.
[to top of second column]
|
Ashaninka's territory sits along the winding Amonia River in Acre
state, Brazil, June 22, 2024. (AP Photo/Jorge Saenz, File)
 “They claim that Indigenous
territories only protect health when forest cover is above 40%. And
so that that feels like, why 40%? Why not 35? Or why not a range?”
she asked. “It doesn’t mean that the study is wrong, but it means
that we need to be cautious because the patterns could change if
different, more precise methods were used.”
Still, she thinks this is a starting point that could open the door
to future research. “They are actually doing something quite
beautiful,” empirically connecting the legal recognition of
Indigenous lands to human health outcomes, she said.
Hernández, of FECOTYBA, said that's important for the global
policymakers who are coming to Brazil.
“From my Indigenous perspective, I think that this type of study
would make our ancestral knowledge more visible and precise,” he
said.
There's a strong body of evidence showing that Indigenous land
tenure helps maintain intact forests, but the paper shows it's
important to maintain forest outside of Indigenous-stewarded areas
as well, said James MacCarthy, a wildfire research manager with the
Global Forest Watch team at the World Resources Institute who worked
on a new report on extreme wildfires and the role of Indigenous
communities in addressing them, and who was not involved with the
study.
Landscapes that produce benefits, and don't harm human health
Prist said the goal of the study was to understand how landscapes
can be healthy for people, but that it would be naive to suggest
that all forest landscapes stay exactly as they are, especially with
the land needs of farming and livestock production.
The world needs landscapes that provide economic services, but also
services that protect people's health, she said.
For Julia Barreto, an ecologist and data scientist who also worked
on the study, it stood out to be part of a team of scientists from
different nations working to make information publicly accessible
and to bring attention to the Amazon.
“It is not only one country, and the whole world is depending on it
somehow,” she said.
___
Associated Press writer Steven Grattan contributed to this report
from Bogota, Colombia.
All contents © copyright 2025 Associated Press. All rights reserved |
