THOSE WHO ANTICIPATED Germany’s collapse in 1923 were wrong. All hope was not lost—not yet. In the second half of the 1920s, the introduction of a new currency curbed the country’s runaway inflation. In addition to an extraordinary blossoming of cultural and intellectual life in Berlin, the economic stability brought about a new political stability. The Nazis’ fortunes at the polls began to suffer. Even sales of Mein Kampf would fall dramatically. “One scarcely heard of Hitler or the Nazis except as butts of jokes,” an American journalist in Germany recalled.1
The Berlin of street battles and food riots turned into the Berlin of avant-garde art and bourgeois dinner parties. At a dinner party at Einstein’s home in 1925, Warburg met a scientist who later recommended that he hire Hans Krebs. When the 25-year-old Krebs arrived at Warburg’s lab for his interview that December, Warburg was characteristically blunt. Though he had been invited to dine with Einstein, Warburg described himself to Krebs, accurately, as an outsider who was disliked by scientists in academia. If Krebs hoped to have a career in academic medicine, Warburg told him, he would be better off attaching himself “to some old ass of a professor.” Warburg was particularly outraged, even prepared to leave the Kaiser Wilhelm Society, when a man he disparagingly referred to as a “bee researcher” received a lifetime appointment to the Institute for Biology before the same offer had been made to him.2
Though the specifics of what transpired are not entirely clear, at one point in the 1920s, Warburg accepted an offer from an institute in Heidelberg. Warburg changed his mind, but he may have done so under pressure. Faculty members in Heidelberg—presumably ones who remembered Warburg from his medical school days—were rumored to be planning a boycott if Warburg took the position.
Warburg might have had legitimate grounds for his complaints about other scientists. In a letter to Jacques Loeb from the same period, Einstein noted, as an aside, that Warburg had “been quite nastily oppressed” by his colleagues. Whatever caused the friction, Warburg had few allies left in the Kaiser Wilhelm Society. Boveri, the man who had chosen him for his position, had been dead for years. Warburg’s greatest supporter at the society, Emil Fischer, had committed suicide in 1919 after being diagnosed with terminal cancer.3
Warburg certainly had reason to be outraged in 1927. That year, he was one of two finalists for the 1926 Nobel Prize for Physiology or Medicine. (The 1926 prize was awarded retroactively in 1927 because no one had been deemed worthy of the award in 1926.) The other finalist, Danish researcher Johannes Fibiger, had discovered that he could induce cancer in rats by feeding them worm-infected cockroaches. Whereas Warburg saw cancer cells eating and multiplying like microbes when oxygen was scarce, Fibiger saw the microbes themselves as the cause of cancer.
Fibiger was far from alone in this respect. An entire generation of cancer researchers took up the hunt for the “cancer microbe,” or “cancer bacillus,” as it was commonly referred to. Warburg, to his credit, never believed that a cancer microbe would be found. As he put it in a talk before the German Chemical Society in the summer of 1926, there is “no cancer bacillus” just as there is “no diabetes or arteriosclerosis bacillus.” Warburg’s reasoning was difficult to dispute. It was already recognized that exposure to tar and radiation and various chemicals could cause cancer without any assistance from tiny organisms.4
That both finalists for the Nobel Prize in Physiology or Medicine were cancer researchers was evidence of the expanding place of cancer in science and in public life in the 1920s. But that two scientists with very different explanations for how the disease arises could both be nominated for the Nobel Prize was also evidence of the state of confusion within the field.
The deadlocked Nobel Committee eventually concluded that Warburg and Fibiger should share the honor. And yet when the announcement was made, it did not include Warburg’s name. The Nobel Committee’s last-minute decision to give the award to Fibiger alone remains unexplained. It would prove to be an embarrassing mistake. Fibiger had failed to run controlled experiments—an ironic turn of events, given that he was among the first researchers to run a randomized controlled trial. In addition to the worm-infected cockroaches, Fibiger’s rats had eaten only bread and water. When researchers later repeated the experiments with rats eating well-rounded diets, they found no tumors. Still further research revealed that the tumors Fibiger had detected weren’t even malignant.
If Warburg had good cause for complaint about the 1926 Nobel Prize, he also had reasons to feel grateful. In a time of relative political calm, Germany was quickly reestablishing itself as the world’s leading scientific nation, and Warburg, hidden away in the top floor of the Kaiser Wilhelm Institute for Biology, was becoming something of a scientific legend. “Warburg already had a mystery about him,” wrote the Nobel laureate Fritz Lipmann, who was then a young researcher working in Otto Meyerhof’s lab in the same building. “We admired him boundlessly but saw little of him.” If they were lucky, Lipmann recalled, young researchers might catch a glimpse of Warburg “when he descended into the lower regions.”5
In addition to building on his cancer findings, Warburg now returned to his prewar investigations of cellular breathing. Warburg’s aim remained the same: he wanted to understand how our cells make the nutrients we eat react with oxygen. In 1913, he had discovered that the enzyme required for cellular breathing—Warburg still called it “the respiratory ferment”—appeared to include iron. But Warburg had nothing close to proof. The next step was to crush yeast cells so that he could isolate the enzyme within the chemical soup that emerged. But given the limitations of his laboratory tools in the 1920s, Warburg had little hope of singling out a molecule that existed in only minuscule quantities inside the cell.
Warburg needed another approach, and he needed it quickly. By 1925, the Cambridge researcher David Keilin was close to solving the riddle of respiration. Keilin had identified a series of metal-infused proteins that were clearly involved in the breathing process, despite Warburg having dismissed them as “degenerate ferments.” But none of the molecules Keilin had found would react directly with oxygen. The molecule Warburg sought was still hidden inside the cell, waiting to be discovered.
Warburg’s breakthrough arrived during a serendipitous supper. At a Berlin dinner party in the winter of 1927, he found himself chatting pleasantly about carbon monoxide poisoning with the English physiologist A. V. Hill. Warburg knew that the gas is poisonous for the same reason that cyanide is poisonous: it binds to iron and prevents the meeting of iron and oxygen in our cells. It amounts to a chemical choking.
But that night, Hill mentioned something Warburg did not know. In 1896, a pair of Scottish researchers had made a peculiar observation: in the dark, carbon monoxide would react with the iron in hemoglobin, the molecule that carries oxygen in blood, but shining a simple beam of light on the hemoglobin could cause the gas to lose its deadly power. It was as if the light, like a security guard, were stepping in carbon monoxide’s way before it could attach to the iron. As the story goes, upon hearing of this surprising finding, Warburg excused himself from the party and went directly to his lab.6
Warburg wasn’t interested in preventing carbon monoxide poisoning. The moment Hill mentioned the strange discovery, Warburg understood that if light was preventing the carbon monoxide from binding to the iron in blood cells, it might have the same effect in every cell. And if the phenomenon did hold true for every cell, then light could provide Warburg with an entirely new way of identifying his invisible respiratory ferment.
Warburg’s insight was based on a principle that had been appreciated for decades. Every molecule in a cell absorbs light differently according to its chemical properties. If Warburg could figure out exactly how much light, at each wavelength, would block the carbon monoxide from attacking iron, it would reveal his respiratory ferment’s unique “absorption spectrum.” If the light functioned as a security guard, the “absorption spectrum” was like a fingerprint the guard collected at the scene of the crime.
As in a criminal investigation, the value of a fingerprint for Warburg was that it could be compared with another fingerprint. Warburg’s plan was to find the fingerprint of the molecule in yeast and then to repeat the same trick in his model system, in which charcoals containing iron functioned much like the respiratory ferment. If the two fingerprints turned out to be identical, it would be as close to proof as possible that Warburg had identified the most fundamental molecule of life, the chemical match in our cells that made it possible to burn food without fire.
The first task for Warburg was to confirm that what Hill had told him was true for blood cells was true for other cells, too. Warburg took a small glass vessel containing a solution with living yeast and oxygen and filled it with carbon monoxide. As expected, the yeast were soon suffocating. Warburg then inserted a lamp covered in a watertight jacket into the vessel. Though he would never have admitted to anything resembling giddiness, Warburg must have been filled with anticipation in that moment. The fate of the yeast in his vessel held enormous implications for his scientific future.
The young Hans Krebs stood by, sensing he was witnessing an important moment in the history of biochemistry. If the breathing rate of the yeast increased, it would be reflected by the rising fluid in Warburg’s manometer. Gazing at the U-shaped tube, Warburg, like a doctor looking hopefully at a flat EKG, desperately needed a sign of life.
And then it happened: the fluid crept up the right arm of the tube. The yeast gradually began to breathe. Warburg immediately went to work shining lights of different wavelengths on the cells until he had his ferment’s fingerprint. Next, he repeated the experiment in his model system with charcoals. The moment he saw that the two fingerprints were the same, he would have understood that his own life would no longer be the same.
On February 22, 1928, Warburg presented the new evidence for his respiratory ferment at a lecture held at the Berlin Palace, a sprawling fifteenth-century structure that had served as the residence of various Prussian kings over the centuries. David Nachmansohn attended the lecture. Decades later, he could still remember the electricity in the room. Those in the audience, he recalled, understood that Warburg hadn’t merely demonstrated an important discovery. By linking cellular breathing to a specific part of a specific molecule, Warburg had launched a new era in science.7
Warburg once told Krebs that it was critical for a scientist to investigate a narrowly defined problem for many years and that such narrow pursuits would, paradoxically, provide answers to the most expansive questions in biology. Now, some 15 years after he had first sprinkled iron salts on crushed sea urchin eggs, Warburg had identified the mechanism of life itself.
AS WORD OF Warburg’s discoveries spread, he was increasingly regarded as the leading figure in his field. In 1929, he traveled to the United States to present his latest work. After a lecture at Johns Hopkins University, Warburg met with officials from the Rockefeller Foundation, who were so impressed that they offered to support him with $20,000 per year for his research. Warburg returned to Dahlem in an unusually good mood, regaling Lotte with stories of the women who had pursued him during his journey home on a luxury ocean liner.
The Rockefeller money was an extraordinary gesture, given how recently America and Germany had been at war, but Warburg had something more in mind. In an exchange of letters with a foundation official, Warburg made the case for an institute of his own. His lab at the Kaiser Wilhelm Institute for Biology, he wrote, wasn’t suitable for the “delicate physical measurements” he hoped to carry out. That was an exaggeration, if not an outright lie, but it mattered little. The Rockefeller officials believed in Warburg’s genius and his importance to cancer science, in particular. On April 16, 1930, the foundation’s board of trustees met in New York and passed a resolution granting the Kaiser Wilhelm Society a lump sum of $655,000 for the building of two new institutes: one for Warburg and one for the study of physics.8
Warburg suggested to the Rockefeller Foundation that his new building could be considered a Rockefeller institute—with the Rockefeller Foundation taking over all of the funding. The director of the Kaiser Wilhelm Society, Friedrich Glum, had not approved the idea and was dismayed when he learned of it. Glum wrote to the Rockefeller Foundation explaining that Warburg’s suggestion that his own institute be given a special status within the Kaiser Wilhelm Society was impossible. Although Glum was, ostensibly, Warburg’s boss and had every right to dismiss the proposal, he asked the Rockefeller Foundation officials not to reveal his intervention to Warburg.9
Additional money for Warburg’s institute would come from the estate of a wealthy woman who was dying of cancer. The woman wanted the building designated a “cancer research institute,” but Warburg refused, arguing that his research couldn’t be reduced to a single medical application. It would be as “ridiculous and unscientific as if a physicist wanted to call himself a radio waves physicist,” Warburg said.10
Work on the new institute in Dahlem began right away. The architect hired for the job drew up plans for a modern Bauhaus-style institute. Warburg glanced at the blueprint and was repulsed. It looked like a “factory,” as he put it. Always fond of rococo, Warburg wanted the architect to model the institute on an eighteenth-century country manor he had seen while traveling with Heiss outside of Potsdam. Though there was no evidence it was true, Warburg liked to say that the manor had been built by one of Frederick the Great’s generals.
The architect was horrified by Warburg’s vision for the building, which would not look anything like the other Kaiser Wilhelm institutes, or any other modern scientific building, for that matter. But Warburg, now at the height of his influence, was not about to let someone else design his dream institute. He had secured the Rockefeller money, and he was going to have an eighteenth-century rococo manor. The windows were to be the same size and to have the identical shutters as the home he had seen near Potsdam; the roof was to be adorned with the identical slate shingles.
The new institute was built exactly to Warburg’s specifications, which called for an imposing oakwood door and a small walkway flanked by rows of lime trees. The contrast between the baroque exterior and the sophisticated scientific equipment inside was a perfect mirror of Warburg himself. To ward off all distractions from his research, Warburg assigned each of his technicians a different managerial responsibility, from paying bills to ordering new glassware.
By the time the institute opened in 1931, Warburg and Heiss had already moved into a new home down the street. The house, too, was built according to Warburg’s detailed instructions. He insisted on 13-foot ceilings, a stone-tiled hallway, and parquet floors. Behind the house, Warburg built a stable for his horses and created a large riding area. When Lotte visited in the spring of 1930, she found Warburg on the terrace drinking coffee with Heiss. A poodle had its head on Warburg’s knee. Looking around at the mahogany furniture and the antique Persian rugs, Lotte was struck by her brother’s talent for reconfiguring the world to his desires. Everything was unique, “as he would have it and no other.” As Lotte said on another occasion, it was as though every last object was a “reflection of Otto’s being.”11
Neighbors who spotted Warburg atop his horse, galloping down the streets each morning in the boots and spurs he had worn with the uhlans, began calling him “the Emperor of Dahlem.” Warburg was indeed shaping every last aspect of his life in a way that only an emperor could. His salary, 36,000 marks, was twice that of a typical science professor of his seniority. His technicians were ready to devote themselves to whatever experiments he might dream up, and perhaps the world’s most generous philanthropic organization was ready to finance those experiments. Few, if any, figures in the history of science have had a better arrangement.12
For summer vacations, Warburg and Heiss would travel (sometimes by horse—a full day’s ride) to Nonnevitz, a quaint village on the island of Rügen in the Baltic Sea, where they maintained a small farm of chickens, geese, ducks, and goats. Warburg referred to it as his own “Noah’s Ark.” He would spend these vacations writing up his research from the previous year. Warburg’s papers, as one colleague put it, were “masterpieces of clarity.”13 The Nobel Prize winner Albert Szent-Györgyi once asked Warburg the secret to writing such well-crafted scientific papers. Warburg explained that he would first write a draft that included everything that came to his mind and then set it aside. He would then return a month later and write the paper again without looking at the original draft. If the second draft differed from the first, he would write a third draft, and so on, sometimes rewriting a paper as many as 16 times before arriving at a point where the text was no longer changing.
It wasn’t all work at Nonnevitz. Warburg would step away from his writing long enough to take long walks by the sea with Heiss. Warburg was said to be a different person during these vacations, more friendly and relaxed. He got along with the locals better than he did with almost anyone in Berlin and would sometimes stop to chat with them about their crops and the conditions of the soil.14
The only thing still missing from Warburg’s idyllic life was a Nobel Prize. It would arrive in 1931, in recognition of his respiration research, along with $31,100 in prize money. Emil Warburg had died only months before, but if Warburg was disappointed that his father didn’t live to see him achieve the great honor, there is no record of it. When the newspaper reporters arrived at his door, Warburg begrudgingly agreed to a photograph with his dogs, and then had Heiss chase everyone away.
At the awards ceremony in Stockholm, the Swedish chemistry professor Einar Hammarsten introduced Warburg and declared his discovery of the respiratory ferment the culmination of a quest begun by Lavoisier in the eighteenth century. The Nobel was important validation for a man who needed it, and yet it would lose a bit of its luster after Warburg met the scientists who had chosen him for the award. As Hammarsten would later recall with amusement, Warburg could hardly believe the decision had been made by “such an obscure” group.15
Shortly after Warburg returned to Berlin, he crossed paths with Einstein at the home of a mutual acquaintance. Warburg told him that he planned to use his Nobel Prize money to buy a white horse with a black stripe that he’d long had his eyes on. Einstein responded that as far as he was concerned, personal possessions shouldn’t matter to a scientist. Warburg was stung. Einstein remained one of his idols. Though it’s not clear that Warburg said anything in response, he was still bothered by the remark days later. He told an acquaintance that Einstein’s dismissal of money and possessions was “nonsense” and that he was happier now that he was more financially secure.
Kaiser Wilhelm Institute for Cell Physiology, around 1940.
Otto Warburg with Prince Wilhelm of Sweden, Nobel Prize reception dinner, 1931.
Arnold Berliner, the physicist who witnessed the moment between Einstein and Warburg, noted in a letter that he planned to tell Warburg that Goethe was on his side of the debate, as Goethe had written that even “if life loses all charm, possessions are still worth something.” Berliner appears to have been unaware that the line comes from Faust and is spoken by Mephistopheles.16
As far as Lotte was concerned, Warburg seemed in the grip of darker forces. He no longer needed the people who “so often annoyed and insulted and lied to him, partly out of their hatred of the Jews, partly out of their envy of his scientific successes,” Lotte wrote in her diary. For another person, independence might have been a positive development, but for Warburg it had a dire consequence: he was free to “indulge in his contempt.” He became “more and more difficult,” according to Lotte, even “vicious” sometimes. In February 1932, less than a year after his institute had been built with Rockefeller Foundation money, Warburg refused to have breakfast with the foundation officials who had come to Dahlem. He did not like late breakfasts, he explained.
Lotte did her best to rationalize Warburg’s coldness. “Thinking with scholars is always at the expense of feeling,” she wrote. “It is impossible to live an idea and a feeling at the same time. One must be sacrificed.” But she couldn’t help but see the perverse direction of Otto’s life: “He achieves everything he wants and becomes harder and harder instead of happier.”
Warburg had just won the Nobel Prize for his discovery of how our cells respire, but Lotte found herself thinking of respiration in a very different way. “It’s hard for the little people to breathe the air of great spirits,” she wrote. “And so it is often difficult to breathe Otto’s air.” Then she added, “It sometimes suffocates you.”17
WARBURG’S FINANCIAL BACKERS, including the Rockefeller Foundation, were primarily interested in his cancer research, and with good reason. Cancer rates were continuing to rise across the West. By the 1920s, the growing number of cancer deaths in Germany had become a national fixation. Cancer, in the words of one prominent German doctor of the era, had become “the number one enemy of the state.”
To confront this enemy, Dresden’s Hygiene Museum created a traveling exhibit called “The Fight Against Cancer.” More than half a million people visited it, so many that police would sometimes have to cordon off the huge crowds that would form outside its temporary exhibit halls. Among the highlights of the exhibit was a silent film seemingly designed to terrify all who saw it. At one point in it, a grim reaper appears over a map of Germany, then slowly expands until the sharp blade of his scythe has stretched across the screen.
The acclaimed German doctor Ferdinand Sauerbruch reported that due to the exhibit, his clinic was being overrun by panic-stricken patients showing up with nothing but warts. He called for the exhibit to be shut down. But it was a symptom of the cancer panic rather than the source. The Germans were terrified for a reason: their friends and relatives were dying of cancer in unprecedented numbers. One cancer film of the era was titled One in Eight, a reference to how many Germans could be expected to die of the disease.18
Cancer was now often referred to as a “disease of civilization,” and “civilization” was typically understood in a positive context. Cancer, in this view, was an unfortunate side effect of modern life. As one British cancer expert of the period put it, cancer was “the price we pay for civilization.” But to some, “civilization” had a very different connotation. The German Romantics had long preached that modern civilization was corrupt and that superior German traits were being diluted amid the departure from nature and the mixing of races in modern cities. That cancer, along with a number of other diseases, had arisen during the period of industrialization, when Germany left its “natural” state, fit perfectly with this racist fantasy. For the Romantics, cancer wasn’t an unfortunate consequence of the modern world. It was more evidence that the modern world was itself a terrible mistake. And the more Germans who died of cancer, the more compelling this perverted logic would appear.19
Cancer epidemiology and racist ideology would come together in the person of Erwin Liek, a Danzig surgeon, known as “the father of Nazi medicine,” who sought to restore health through a return to natural living and healing. Liek, who wrote two popular books on cancer, was convinced that malignant growths were a problem of “civilization” and “not found among savages.” “[T]he simpler and more natural one’s way of life,” wrote Liek, “the rarer is cancer.”20
Liek, a eugenicist, maintained that civilization undermined the health of the German race by keeping weak and defective people alive—and thus able to pass on their defects to the next generation. He visited the United States in 1912, working at the Mayo Clinic, among other hospitals, and was delighted to discover that the nation had no social insurance programs. (That the doughy Liek was not in robust health himself—he died in 1935 at age 56—does not appear to have ever given him pause.)
But the problem with modern civilization wasn’t merely that it was too forgiving of the feeble. Liek, like Germans who were not Romantics—and many people today—was convinced that modern life had brought with it an almost endless list of carcinogens. His books on cancer discuss dozens of cancer-causing agents: air and water pollution, artificial fertilizers, tobacco, insufficient activity, stress, and the dangers of aluminum pans and utensils, among others. That cancer was more and more common was terrifying in its own right. That almost every aspect of modern life could be said to cause cancer was enough to make anyone panic.
The greatest environmental threat of all, Liek and other German cancer specialists were coming to believe, was the German diet. By the late 1920s, Germans were arguably more concerned with the connection between diet and cancer than any other nation in the world. Some Germans believed that the danger stemmed from what Germans were not eating. New evidence showed the links between nutritional deficits and public health scourges. Goiters were traced to a lack of iodine, rickets to insufficient vitamin D. Perhaps cancer, too, would eventually be linked to a specific nutrient that was lost when food was cooked or grains refined.
What was added to food was thought to be even more problematic. The same coal-derived chemicals that had given rise to colorful clothing and to Ehrlich’s chemotherapies were making German foods brighter. Bread was being bleached with benzoyl peroxide. Still other chemicals were used to preserve foods that would have gone bad under natural conditions. “The foods produced by our earth are good,” Liek wrote, “those denatured by humans are bad.”21
Liek’s books revealed the influence of Frederick Hoffman, the German American insurance analyst whose 1915 tome, The Mortality from Cancer throughout the World, concluded both that cancer was a “disease of civilization” and that it was becoming increasingly common in the modern world. Researching and writing the book had required a monumental effort, but Hoffman did not slow down after it was published. Once convinced that cancer was on the rise, he was determined to figure out why.
While he had previously relied on the work of others in his analysis, in 1924 Hoffman started conducting his own population studies. His primary effort was a study of cancer in San Francisco, which then had the highest cancer death rate in the country: 160 cancer deaths for every 100,000 citizens, nearly double the average American rate. The study included thousands of surveys on the lifestyles and eating habits of San Franciscans, both cancer patients and control groups, and a review of some 50,000 death certificates. During the same period Hoffman also conducted surveys from countries across the world, including Mexico, India, Malta, Sudan, Iceland, the Philippine Islands, and New Zealand.
Hoffman was an early adopter and proponent of air travel—he became known as “the flying actuary”—and often collected his data in person. But the nonstop travel and writing—he published over 1,200 papers during the course of his career—began to take a toll. In the spring of 1927, Hoffman collapsed in Newark, New Jersey, and was rushed to the St. Barnabas Hospital, where he was diagnosed with pneumonia. As the concerned doctors looked on, Hoffman fell into delirious fits, reciting a lecture on cancer he had been preparing for his upcoming address in Brussels.
Hoffman’s doctors gave him only a 50 percent chance to make it. He left the hospital for Europe a week later. In addition to his lecture in Brussels, he stopped in Berlin to address the German Society for Cancer Research on the use of statistics in cancer investigations. A brief Rockefeller report on the event mentions that Otto Warburg, still in the early stages of unraveling how cancer cells eat, was among the German scientists in attendance.22
If Hoffman was gathering cancer statistics in the 1920s with a sense of urgency, it was, in part, because the predictions he made in his 1915 book about the coming cancer epidemic were looking accurate. Hoffman had been aghast in 1915 that approximately 80,000 Americans were dying of cancer each year. By the late 1920s, the number had grown to about 145,000, and Americans, like Germans, were growing increasingly worried. In 1928, West Virginia senator Matthew Neely stood in front of Congress waving a copy of Hoffman’s book and declared cancer “more terrifying than any scourge that has ever threatened the existence of the human race.”23
By the end of his San Francisco survey, Hoffman was convinced that he had found an explanation for the increase in cancer. The cancer problem, first and foremost, was a problem of food—a problem, Hoffman wrote, of the “essential errors” that “underlie the modern diet of civilised races.” In 1937, Hoffman published Cancer and Diet, a 767-page book presenting a mountain of new data as well as a review of every source he could find on the subject, dating back to antiquity. In the book, Hoffman noted that the rest of the world had fallen behind the Germans in their research into nutrition’s role in cancer. He mentioned Warburg’s “epoch making treatise” on the metabolism of cancer cells more than a dozen times.24
If Hoffman had moved beyond the long list of possible carcinogens he’d discussed in 1915 to a focus on nutrition, it clarified only so much. There was still a dizzying number of foods and preservatives and cooking methods to worry about, and every expert offered different advice. Germany’s traveling cancer exhibition called for a diet high in fruit and fiber and warned Germans against too much fat, sugar, and protein. Liek recommended avoiding meat and sweets (with the exception of honey) and eating dark bread along with fruits and vegetables. Hoffman encouraged his readers to be aware of vitamin and mineral deficiencies and singled out tomatoes and salt as particularly harmful.
Hoffman had arrived at his conclusion that the Western diet was responsible for cancer largely based on the scarcity of cancer in populations that followed traditional diets. Yet when it came to identifying the specific culprits in the Western diet, the comparisons between Western and non-Western populations were less helpful. It might be true that neither the Inuit of the Artic nor the Gabonese of West Africa developed cancer when following their traditional diets, but their traditional diets were remarkably different from one another. The Inuit ate almost exclusively animal products, while the Hunza of the Himalayas ate a diet rich in plant foods.
That an anxiety about carcinogens in food had become entangled in a profoundly racist Romanticism didn’t necessarily mean the anxiety was misplaced. It is possible to be simultaneously correct on the facts and wrong on their meaning. But Romantics like Erwin Liek faced an empirical problem as well. For all the concerns about carcinogens, the evidence linking any particular food or nutrient to cancer was not particularly strong. “[I]t certainly seems exceedingly rash to attempt to make us believe that there is any connection between cancer and diet,” the Dutch cancer authority H. J. Deelman argued. As Deelman noted, for all the new emphasis on diet, the larger problem of distinguishing the influence of diet from other factors in the environment had hardly disappeared. The cancer-free populations didn’t only follow different diets. They had, Deelman wrote, a “wholly different mode of living.”25
Liek pushed back against his critics as best he could. Though he detested what he saw as the mechanistic science of researchers like Warburg, he didn’t hesitate to bring up Warburg’s findings as evidence that nutrition was linked to “metabolic disruptions in cancer tissue.” And yet there was only so much Liek or Hoffman could say. Deelman’s position was scientifically sound. He was not denying that cancer was becoming more common in industrialized countries, only that the diet hypothesis was far from proven.26
If Hoffman and the German cancer establishment remained confused about the connection between eating and cancer, they were circling around something fundamental. They had noticed that cancer rates rose in industrialized societies and that the cause appeared to be related to food. With the publication of Cancer and Diet in 1937, Hoffman had reason to believe that the rest of the world would follow Germany’s lead in focusing on the relationship between diet and cancer.
Perhaps the medical establishment would have taken the cancer-diet connection more seriously had the thinking not fallen into the wrong hands and been forever tainted.
CANCER WASN’T Hitler’s only health concern. August Kubizek, the friend from Hitler’s early years—the two shared a room in Vienna in 1908—remembered that Hitler was “almost pathologically sensitive about anything concerning the body.” And though Hitler’s health had been generally good in the 1920s, he had an acute fear of death. “When I’m no longer here” had become Hitler’s “mantra,” Goebbels noted in his diary at the time.27
In 1924, Hitler cut back on meat and alcohol. He explained the decision with a vague reference to his health and weight, but he later credited his turn to vegetarianism to Richard Wagner, whom he idolized. In an 1881 essay, Wagner had written that vegetarianism was the original human diet and that eating animal flesh, along with the mixing of racial groups, had contaminated the human race. The essay inspired one of Wagner’s zealous admirers to move to Paraguay, where he could establish a colony free of meat and Jews. Hitler, more ambitiously, wanted Germany to be his vegetarian, Jew-free utopia.28
But if Hitler’s hypochondria would manifest itself in many different forms, it was cancer that terrified him most. He had long worried that his stomach cramps and severe bloating were evidence of the disease, and with each passing year, his anxiety would deepen. That his fears were shaped by his experience of watching his mother suffer from an experimental cancer treatment is obvious from Mein Kampf. In one passage Hitler argues that Germany’s military should be no more hesitant to take bold risks than a dying cancer patient who embraces treatment even “if the operation promises only half a percent likelihood of cure.” In a critique of the Austro-Hungarian Empire, Hitler wrote, metaphorically, that “its weakness in combating even malignant tumors was glaring.”29
Cancer was an easy metaphor in the 1920s, as it is today. But the frequency with which Hitler relied on it in his writing and speeches is telling. In some instances, he likens Germany itself to a dying cancer patient. Hitler, in turn, presents himself as the surgeon, “lancing the cancerous ulcer” and “combating malignant tumors.” In 1928, his cramps drove Hitler to see a doctor, who diagnosed him with chronic irritation of the stomach and recommended an even more restrictive diet. When the cramps persisted, so did Hitler’s fixations on cancer and food.30
At some point—it’s not clear when—Hitler became an admirer of Erwin Liek. Even before being named chancellor, Hitler would personally offer Liek the position of Reich Physicians’ Führer. And in his uniquely confused way, Hitler, too, would also come to see cancer as a “disease of civilization.” Perhaps directly influenced by Liek, he suspected that the act of cooking, by taking food out of its natural state, was the root of the problem. He repeatedly returned to this theme during his mealtime rants:
Nine-tenths of our diet are made up of foods deprived of their biological qualities. When I’m told that 50 per cent of dogs die of cancer, there must be an explanation for that. Nature has predisposed the dog to feed on raw meat, by tearing up other animals. Today the dog feeds almost exclusively on mixed bread and cooked meat. If I offer a child the choice between a pear and a piece of meat, he’ll quickly choose the pear. That’s his atavistic instinct speaking. Country folk spend fourteen hours a day in the fresh air. Yet by the age of forty-five they’re old, and the mortality amongst them is enormous. That’s the result of an error in their diet. They eat only cooked foods. It’s a mistake to think that man should be guided by his greed. Nature spontaneously eliminates all that has no gift for life. Man, alone amongst the living creatures, tries to deny the laws of nature.31
The most striking account of Hitler’s thinking on diet and cancer in this period comes from Albert Krebs (no relation to Hans Krebs), a regional Nazi leader who was with Hitler in the Atlantik Hotel in Hamburg in February 1932. Hitler, who was campaigning for the German presidency, had delivered a speech the night before. Knowing that Hitler liked to review the published transcripts of his speeches, Krebs planned to show him the morning newspaper. But as Krebs made his way down to Hitler’s suite, he heard “rhythmic cries” of “M’soup!” In the first room of the suite, Krebs found Hitler’s entourage frantically scrambling to prepare another serving for their aggravated führer. It “was like a scene from a French comedy,” Krebs wrote.32
Krebs continued on to the farthest room in the suite, where he found Hitler “hunched over a round table, looking melancholic and weary, slowly slurping his vegetable soup.” When Krebs showed him the newspaper, Hitler shoved it aside. He had something else he wanted to discuss. He began to question Krebs “urgently and with obvious anxiety” about his views on vegetarian diets.
Krebs wasn’t sure how to respond, but Hitler wasn’t interested in his response. He “launched into a lengthy and detailed lecture” on health food. Krebs knew Hitler well enough not to be startled by his ranting, but that morning Hitler did, in fact, surprise Krebs. For the first time, Hitler took a conversation with Krebs in a personal direction, speaking openly of his fears of illness, even listing the symptoms—sweating, extreme nervousness, trembling, and more—that had led him to adopt his meat-free diet. “This revelation of weakness in an unguarded moment,” Krebs wrote, “threatened to expose the hidden truth: that his ‘strength’ was only an overcompensation.”
Hitler also told Krebs of the stomach cramps that he feared were symptoms of cancer. It’s possible that the very name “Krebs” had unsettled Hitler. “Krebs” is the German word for cancer. Both “cancer” and “Krebs” are derived from karkinos, the ancient Greek for “crab.” (Hippocrates is thought to have named the disease, though why cancers made him think of crabs is unclear.) In German, “Krebs” can also refer to actual crabs, as well as crayfish and lobsters, and Hitler was fascinated by these sea creatures. Some scholars have suggested that it was more than a coincidence that Hitler’s mind was on cancer even as he gazed at shellfish.
As Albert Krebs sat and listened in amazement, Hitler said that it was the knowledge that he was dying that made his election so critical. If he didn’t come to power soon, Hitler said, he wouldn’t have enough time left to “finish the gigantic tasks” he had in mind.
With those words, Hitler suddenly regained control and turned his attention to the newspaper and his speech. “The depression was overcome,” Krebs wrote. “Hitler the human being had changed back into the Führer.”
Adolf Hitler, broken glass-plate negative, date unknown.
