Comparing Arsenic to MSG as far as both being natural is crazy. One is a science proven poison . The other has never been science proven, nor is it a poison. Would you sprinkle arsenic on your food or incorporate it in . I doubt it.
Arsenic by the way years ago was given to infants when their digestive track could not keep food down. Minute amount of arsenic was given to open the organs that led to th stomach. Don't believe me ask an older gastro doctor. Plus I know first hand, as I was one of those babies.
Over 50 years in food service business 35 as Ex Chef. Specializing in Volume upscale Catering both on and off premise .(former Exec. Chef in the largest on premise caterer in US with 17 Million Dollars per year annual volume).
Well versed in all facets of Continental Cuisine...