I heard that too. However, in my case, I may have started at 11, but my cycles stopped dead 3 months after I turned only 41.
After learning about Iodine I instinctively thought the absense of flow might have been due to Iodine deficiency but that was a 'gut feeling'...
My uterus has sure been giving me fits again lately! (not painful) A while back, my chiropractor pretty much confirmed my 'gut feeling' when he said: "I have seen cycles return after MANY years of amenorrhea once nutritional deficiencies have been corrected."
Remember when you read any old research, too! A tremendous deal of research, of which we base our present knowledge of "known facts", was done on people who were already iodine-deficient!!!