The study confirms that intact forests in Indigenous territories significantly reduce the spread of 27 diseases, including malaria, Chagas, and respiratory illnesses linked to wildfire smoke. Forest cover is critical: Health benefits diminish when forest cover drops below 45%, with deforestation and fragmentation sharply increasing disease risks. Health benefits diminish when forest cover drops below 45%, with deforestation and fragmentation sharply increasing disease risks. A landmark study has found that Indigenous-managed territories across the Amazon provide powerful public health benefits. The research also highlights the importance of legal recognition of Indigenous land rights.