I have remarkable personal experience that, in my opinion supports the conclusion in this article.
Very briefly, beginning at age 6, I became sickly and had asthma for the next 40 years, requiring two medications almost continually. In an attempt to lose a middle-age related weight gain, I began fasting, eating absolutely nothing but drinking plenty of water. To my unanticipated delight, I noticed that after 5 days, my asthma symptoms had disappeared. Suspecting a food allergy cause, I continued fasting for a total of 10 days, and began eating again, with certain food groups only, in order to determine which one might have been the issue. Nothing that I ate caused the symptoms to return, and I discontinued using any asthma medicine. That was in October of 1999. To my total, unexpected surprise, not only has the asthma never returned, but since then, I never catch a cold, the flu, or any other illness or discomfort. I have to have annual physicals to remain an adult volunteer in the BSA, and I always check out fine, with no problems at all.
It would be interesting to hear from anyone else who had similar results from, by all appearances to me, nothing but fasting.