The words of the sonnet that initiated this line of diagnostic disputations indicate that Michelangelo was aware of the ancient Roman belief that some water (today’s iodine-deficient), was the cause of goiter.7,9 This was the case in the Alpine regions, in which the river water was addressed as “unhealthy for the throat,” or a possible cause for the “swollen throat.”5,7,9 This comment instigated a flow of hypothetical narratives that are interesting for interpreting the sketch and the fresco, although they are less scientific. Only a few are worthy of mentioning.
In their discussions, Martino and Mariotti argued that Michelangelo spent part of his youth in in a mountain valley of the Etruscan Apennines, a region known for endemic goiter. However, there is no evidence whatsoever that the Master, whilst living in his birthplace, exhibited any physical or mental retardation due to iodine deficiency. Indeed his physical prowess was eminent, and his intellectual development was appreciated at the Medici court when the Master was only in his teens. These two authors considered the Master’s goiter already present when he began painting the Sistine Chapel in Rome.6
This goiter hypothesis was further supported by Bondeson and Bondeson, interpreted based on the evidence that whilst working on the Sistine Chapel the artist made God in his own goitrous image (Figure 2).5 The authors of the present article found no evidence of such goiter in the fresco.
The imaginary theory was even further extended, connecting the external features of the neck with the internal neuro-anatomy of the cerebrum. Suk and Tamargo proposed that, in the Separation of Light From Darkness, Michelangelo drew in God’s neck a ventral view of the brainstem.10 The hypothesis that Michelangelo depicted himself as the goitrous Creator of the fresco is interesting but in our view not acceptable (Figure 2).
In 1509, at the time of the above-mentioned sonnet composition, Michelangelo was only 34 and was working long hours on a scaffold, with his neck hyper-extended. He was well and active. Assessed behaviorally, the Master was at times irritated, nervous, but there was no evidence of a hyperactive thyroid. It would be unrealistic to propose as a sign of thyrotoxicosis the single-minded work routine, unusual lifestyle, limited interests, poor social and communication skills, and issues of life control.11
Morphologically, in almost all portraits and self-portraits, Michelangelo is shown with a long beard. The Master painted three self-portraits as Jeremiah (on the ceiling of the Chapel), as the flayed skin figure displayed by Saint Bartholomew (in the Sistine Chapel’s “Last Judgment”), in the “Crucifixion of Saint Peter” (the Vatican’s Pauline Chapel), all with their neck covered, preventing any proper diagnosis of goiter.
Michelangelo was also depicted by Raphael (as Heraclitus in The School of Athens, sitting on the front steps), and portraits were painted by Jacopino del Conte, Daniele da Volterra, and Pompeo di Giulio Caccini. They all portrayed the bearded Master in his later years of life, or copied after his death, similarly preventing any anatomical diagnosis. In our view, no goiter or neck swelling is visible in any of the aforementioned Michelangelo portraits (Figure 3).
Close-up of Michelangelo’s portraits.
Michelangelo wrote over three hundred sonnets and madrigals, and there is no mention of goiter other than in the above-mentioned “Sonnet V” sent to Giovanni da Pistoia. The Master lived for 89 years, and no sign of hyper- or hypothyroidism was described by contemporaries. His self-portraits, his activities, his long life—all would argue against any thyroid pathology.
Finally, our critical review of two major biographies (by Giorgio Vasari and Ascanio Condivi), as well as of his extensive correspondence, found no mention of goiter.1,2,12 It is also unlikely that the thermal water of Fiuggi, with which Michelangelo used to cure his nephrolithiasis, solved the goiter, as that water is not iodine-rich.13–15