Original sentence: Alternative medicine is typically not backed by scientific evidence in the same sense that mainstream medicine is, both because the system of peer review discourages divergent philosophies, and because proponents of alternative medicine tend to be suspicious of the limitations of the materialistic world view of the scientific community.The treatments are those that are not part of the conventional, science-based healthcare system
Edited sentence: The treatments are those that are not part of the conventional, science-based healthcare system, and are not backed by scientific evidence