Human beings once died from starvation, poisoning, or predators; now the more common killer is slower and self-inflicted. This film argues that processed food, excess alcohol, and chronic stress have replaced those older threats, and it spends most of its runtime on the last of the three. It lays out what sustained, repeated stress responses do to the body over decades: measurable deterioration in the brain and a weakened immune system that leaves people less able to fight off disease. The case is built as a comparison across roughly a human lifespan, contrasting sudden ancient dangers with the drawn-out, everyday pressures of modern life, and the film's position is that this damage is largely avoidable through choices people can actually make. It stays close to physiology throughout, framing stress not as a mood but as a biological process with consequences that accumulate quietly until they surface as illness.