Medieval Advice for Living Forever

In recent years, the quest for eternal life has become big business, as a growing number of biotechnology start-ups race to develop a drug which can prevent aging. Many of them are funded by Silicon Valley billionaires who hope to be the first humans to live forever, and who have personally committed to strict health regimes in the hope of achieving this goal.

While the technology may be new, the quest for longevity is not. Indeed, it was also an obsession of elite medieval Europeans. Then and now, the quest for immortality is based on optimizing the body, using lifestyle changes and more outlandish techniques, in an attempt to prolong life beyond its usual span. And yet, the lesson, then and now, seems to be that the quest for immortality is less about advancing scientific knowledge for the good of all mankind, and more about harnessing that knowledge for the benefit of the most privileged members of society.

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Although plague and other infectious diseases brought high death rates in medieval Europe, those who reached adulthood had a reasonable chance of surviving into their seventh or eighth decade; in some early 15th century Italian towns, around 15% of the population was over 60. Just like us, medieval people wanted to live long, healthy lives and hoped to emulate long-lived relatives. The 14th-century Italian poet Petrarch’s grandfather supposedly lived to be 104, while the Florentine politician Donato Velluti (1313-70) claimed that his ancestor Bonaccorso di Pietro (d. 1296) reached 120. In his final years, Velluti described him as blind and very stiff, but still active and sharp-minded.

Indeed, medieval people believed that humans had the capacity to live for centuries, just as Biblical figures such as Noah and Methuselah did. This conviction fueled numerous attempts to work out how they could do so. Writing around 1460, the Italian physician Michele Savonarola complained that, while the ancients thrived on acorns and chestnuts, the gluttony of modern people made them weak and vulnerable to disease. Sex was also a problem: the French rabbi David Kimhi (1160-1235) suggested that people in Genesis enjoyed long lives because they were not slaves to lechery.

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Modern longevity gurus typically offer their followers detailed instructions on how to live their lives, and medieval people were equally convinced of the benefits of micromanaging one’s daily regime. Prevention was at the heart of medieval medical theory: it was widely believed that managing the six non-naturals (air and environment, food and drink, excretion, sleeping and waking, motion and rest, and the passions of the soul) would help an individual to remain healthy.

Medieval medical experts stressed that such an approach became increasingly important later in life, because as a person aged, their body cooled and dried—and death occurred when all of their heat and moisture was used up. Few people believed that it was possible to stop this happening, but there was plenty of discussion about slowing the process down.

Regimens such as Gabriele Zerbi’s Gerontocomia and Marsilio Ficino’s On a Long Life (both published in 1489) included detailed, medically-informed advice on how to prolong one’s life. Some of their suggestions might seem ridiculous to modern readers. Zerbi, for instance, warned his readers to avoid both sneezing and sex, which dry out the body, as well as cutting fingernails under certain astrological combinations.

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But much of their advice has persisted. Medieval doctors told their patients to exercise, get enough sleep, take care of one’s mental health, and avoid excessive alcohol consumption. Above all, it was important to eat a healthy diet, a subject which is covered in exhaustive detail in both medieval and modern regimens. In addition, medieval people were intrigued by the possibilities of fasting. The elderly Petrarch, for example, decided to fast because many of the Desert Fathers (the early Christian hermits whose ascetic lifestyle proved the template for medieval monasticism) had lived to be over 100. The Italian priest-physician Marsilio Ficino recommended eating just two small meals a day, no more than nine hours apart. He also advised against eating too much meat, green fruits, and vegetables.

Beyond diet and lifestyle choices, medieval longevity experts also believed in the rejuvenating potential of young blood. Marsilio Ficino suggested that the elderly could be reinvigorated with an infusion of youthful bodily fluids, which would provide much-needed heat and moisture. This might involve drinking the milk of a "healthy, beautiful, cheerful and temperate" girl, or sucking blood from a "willing, healthy, happy and temperate" youth through a small incision in his left arm. Slightly less gruesome strategies included rubbing fresh pig’s blood onto the stomach, or hugging "a girl who is close to her menstruation" as one slept.

Increasingly, however, the ultimate ingredient for the medieval health freak was gold—a perfectly composed and virtually indestructible element which would help the human body to exist in a state of perfect health for many years. According to the papal physician Arnold of Villanova (d. 1311), many clerics sucked gold nuggets or drank potable gold with their meals. Confident that such practices would preserve their health and prolong their lives, they "consider[ed] gold as the greatest secret they ever knew or possessed." Three centuries later, Renaissance popes were still paying their physicians to make gold-based elixirs to allow them to live to 120.

Whereas some aspects of a healthy lifestyle are quite widely accessible, such costly prophylactic measures were only available to the wealthiest members of society. Whereas Marsilio Ficino openly declared that On a Long Life was written only for "prudent and temperate people of sophisticated intelligence who will benefit mankind," modern longevity specialists often insist that their findings will help everyone. But it is hard to ignore the reality that most modern strategies for the prolongation of life are, like their medieval equivalents, available only to those who have ample supplies of both time and money.

And if the Middle Ages raise important questions about the ethical implications of longevity science, they also offer cautionary tales about its limits. Being at the forefront of medical endeavor brings rewards but also risks, and some of the medieval strategies may actually have caused health problems. The same could be true of modern longevity techniques.

Nor is there any guarantee that you will outwit fate, which seems to have a sense of humor. Pope John XXII (d. 1277) repeatedly and very publicly claimed that he knew how to prolong his life by many years, only to die when a ceiling collapsed on him. Gabriele Zerbi also met an untimely end, murdered by the disgruntled family of a patient. In the Middle Ages as today, medical knowledge might extend your life—but only if you were possessed of both wealth and good luck.

Katherine Harvey is an Honorary Research Fellow at Birkbeck, University of London. She is the author of The Fires of Lust: Sex in the Middle Ages (Reaktion, 2021), and is currently working on a book about medieval approaches to healthy living. Made by History takes readers beyond the headlines with articles written and edited by professional historians. Learn more about Made by History at TIME here.