Higher incidence in females may be because the inter-vertebral space is smaller in women, meaning a smaller bulge is needed to pressure the nerve root. I feel that she makes a good case. She feels not enough is known about spinal mechanics to make this a fatal point. After all war conditions or manual occupations increase the likelihood of cumulative or major wear on the spine. So does the increased incidence with age.
Some researchers regard it as a combination of factors.
I'm not sure. It may be partly right with other factors involved. In it he presents a plausible case that many complicated health problems may be influenced by, though not directly caused by, overgrowth of candida albicans a yeast, in the gut. It gets out of hand apparently when other intestinal fauna is killed off by heavy antibiotic use. Sjogren's Syndrome is not part of fibromyalgia.