Abstract
Historical documents suggest Leonardo da Vinci was vegetarian and his diet may have contributed to the right hemiparesis that troubled him during the last five years of his life.
Giorgio Vasari (1511–74) published the first known biography of Leonardo in 1550, based mostly on first-hand accounts of Leonardo's contemporaries. 1,2 Leonardo was a vegetarian, and had respect and love for animals. Jean Paul Richter wrote: ‘We are led to believe that Leonardo himself was a vegetarian from following the interesting passage in the first of Andrea Corsali's letters to Giuliano de Medici (“Certain infidels called Guzzarati [Hindus] do not feed upon anything that contains blood, nor do they permit among them any injury be done to any living thing, like our Leonardo da Vinci”)’. 3,4 Eugene Muntz wrote: ‘It appears from Corsali's letter that Leonardo ate no meat but lived entirely on vegetables, thus forestalling modern vegetarians by several centuries’. 5 Similarly, Serge Bramly wrote that ‘Leonardo loved animals so much, it seems, that he turned vegetarian’. 6 Vezzosi also referred to Leonardo as a vegetarian. 6,7
Leonardo suffered from right hemiparesis in the last five years of his life. Vezzosi stated that the semi-paralysis of the right side of Leonardo's body would not have affected this left-handed artist's ability to sketch although it did hamper his mobility. ‘It probably prevented him from standing up to paint and from holding a palette – but he would still have had enough strength to sit down and draw,’ claims Vezzosi who writes further: ‘The painting shows us an elderly Leonardo with all the signs of age, with his right hand suspended in a stiff, contracted position, held up by his robe as if it were a bandage’. He also reported that the paralysis would explain Leonardo's inactivity for the last five years of his life, with several of his paintings left incomplete. 8
Although suffering from a paralysis of the right hand, Leonardo continued to draw with his right hand and to teach. However, with his left hand he was better than the average right-handed person. The main historical reference, based on a visit to Leonardo on 10 October 1517, is that of Antonio de Beatis who wrote in his diary: ‘One cannot indeed expect any more good work from him, as a certain paralysis has crippled his right hand. But he has a pupil, a Milanese, who works well enough. And although Messer Leonardo can no longer paint with the sweetness which was peculiar to him, he can still design and instruct others …’ 9
A vegetarian diet might lower the risk of cardiovascular disease by multiple mechanisms. 10 Although a vegetarian diet can be useful for a short time, its effects over the long term are likely to contribute to the risk of stroke. Most vegetable oils are low in saturated fatty acids and some are rich, and high intake has been associated with elevated plasma cholesterol levels and may be associated with atherosclerosis. 11
Vegetarianism affects levels of vitamin B12, folic acid and homocysteine levels, which are related to cardiovascular disease. 12 The intake of vitamin B12 is lower in vegetarian diets and deficiencies in this vitamin have been reported in vegetarians, especially in vegans, leading to increased plasma homocysteine concentrations. 13–15 Hyperhomocysteinaemia is accepted as an important risk factor for stroke. Elevated plasma total homocysteine with a low concentration of folate and vitamin B6 is a strong, graded, independent risk factor for myocardial infarction and other vascular events including stroke. 16,17 Supplementation with folic acid, pyridoxine and vitamin B12 may be associated with regression of atherosclerotic plaque in the carotid artery and prevention of death from vascular causes. 18
Leonardo may have suffered adverse effects from his vegetarian diet. His stroke, which resulted in a right hemiparesis, may have been related to increased homocysteine levels following a prolonged vegetarian diet. Nevertheless, stroke remains a common disorder of multiple causation.