People will get sick one day, and ancient medical technology is zero. Why did Jiang Ziya live for more than one hundred years?
There is a thing called health preservation. Is there no reason why people get sick? For example, a cold and fever are caused by a cold, and a stomachache has eaten something bad. Jiang Ziya can keep furious, work and rest on time, eat normally, not pursue fame and fortune excessively, eat health-preserving things and so on, so he can enter a state of natural death.