Corelation is not causation. I remember when Layton Kor was convinced that his diet of lettuce, carrots, and celery had cured his lung disease. Then I read that it was either spontaneously cured by the body's immune system or the patients died despite treatment. He said it was lettuce, I say it was luck.
Just a comment to Cliffhanger: Many of these extreme diets are very dangerous to diabetics. I was really overweight about 12 years ago (>235 pounds) and I tried the "Adkins Diet." This avoids carbohydrates and focusses on eating a high fat diet, all the while monitoring urinary ketones with ketostrips. It deliberately induces ketosis, but the weight loss is phenomenal, and I went down to 192 pounds in under 6 weeks. I went up to climb Mt. Huron over near Buena Vista, CO, and started having visual hallucinations that I attributed to symptoms similar to diabetic insulin shock. Stopped the diet, but several side effects stayed with me for quite some time: irregular heartbeat and occasional bouts of vertigo. My tolerance for caffeine (too much coffee) was affected as well, so I monitor my caffeine intake carefully in order to retain my FAA flight medical status (Class 2 Medical for Commercial Pilots).