Paul Ewald has lots of interesting ideas, but this one got me thinking. He theorizes that the common diseases are are plagued with (from cancer to heart attacks) will be found to be caused by infectious organisms. (Cartoons lifted from this awesome site)
At first I was skeptical, but it does make some sense that chronic low-level infections could be missed for years while doing damage to our bodies. Examples of cervical cancer (HPV) and ulcers (H. pylori) are convincing, not to mention more obvious examples like Tazmanian devil facial tumors.
There was recent NPR coverage about surgical instruments used in the brain potentially spreading a prion-type protein causing Alzheimer’s. Prions are scary.
Looking into it further I found that the American Cancer Society has a publication on infections that cause cancer, ranging from viruses to parasitic worms. This is really something to think about.