The link between oral health and systemic health has been a very hot topic lately. With the Netflix "documentary" The Root Cause, and several recently published articles have pushed the topic into public awareness.
The thing that is really upsetting many of us in the dental community is that most of the "science" and "experts" that are featured in the film are not exactly reliable. The experts include Dr. Weston Price, whose research from the early 1900's has been called into question due to poor experimental practices, Dr. Hal Huggins, whose dental licence was revoked due to gross negligence, and Dr. Boyd Haley, a chemist who claimed that vaccines cause autism though he has no background in child neurology, epidemiology, or genetics, making him the opposite of an expert.
The science that is often cited in the "studies" that support the film refer to cancer or other systemic disease being on the same "Meridian" as the root canal. The meridian concept comes from Chinese medicine which claims that the meridians allow the flow of energy throughout the body. These meridians do no correspond with any know anatomical structures such as veins, arteries, or nerve channels.
The Truth(As We Know It)
There is a very real correlation between oral health and your overall health. However, there is no scientific evidence to suggest that root canals cause cancer. Accredited Dentists recommend root canal treatment to save their patients from severe acute infection which does have documented serious effects such as airway involvement or spread of the infection to the eye or brain, and considerable pain.
The film The Root Cause is full of unsubstantiated claims, logical fallacy, and studies that would be laughed out of any respected peer reviewed journal. We can't tell you what to believe, but this one should really be put in the trash. There are links below to other reviews of the film.