IN THE 1930s, even as the Nazis were carrying out the first stages of their war against the Jews, they were engaged in another war that seems antithetical to the inhumanity of the rest of the Nazi agenda. This second war was a progressive war, a war to defeat cancer. Shortly after Hitler came to power, the general secretary of the Reich Anticancer Committee promised that the Nazis would engage in “planned cancer combat” unlike anything that had ever come before—and this, at least, was not propaganda.1
The Nazis did not start Germany’s campaign against cancer—the country had been at the forefront of cancer research for decades—but they accelerated it greatly. Thirty years before the American medical community, the Nazis were encouraging women to examine their own breasts for lumps. At “cancer counseling centers” built by the Nazis, the public learned about the danger of asbestos, pesticides, and other chemicals long before other countries had begun to take such threats seriously. One Nazi regulation even required bakeries to produce whole-grain bread, in part out of the fear that the benzoyl peroxide used to bleach white bread could cause cancer.
That the Nazis were introducing legislation to distinguish half-Jews from quarter-Jews at the same moment they were introducing laws to keep the population safe from dangerous chemicals was not a coincidence. For all its progressive innovations, the battle against cancer wasn’t an aberration from the other tenets of Nazism. The entire Nazi project, Stanford historian Robert Proctor argues, can be thought of “as an experiment of sorts—a vast hygienic experiment designed to bring about an exclusionist sanitary utopia.” The Jews, though the most feared and hated, were only one of the many supposed pollutants the Nazis planned to eradicate. In Mein Kampf, it can seem as though Hitler’s unstable mind is incapable even of distinguishing Jews from bodily growths, as though the metaphor collapses under the weight of his rage. “Was there any form of filth or profligacy, particularly in cultural life, without at least one Jew involved in it?” Hitler wrote. “If you cut even cautiously into such an abscess, you found, like a maggot in a rotting body, often dazzled by the sudden light—a kike!”2
HITLER’S FOCUS ON diet and cancer only intensified after he became chancellor. In 1933, eager to learn more about health and vegetarianism, he met with an 80-year-old healer known for her herbal and cold-water cures. Later that day, when a Gestapo officer tried to turn his attention to political matters, Hitler grew agitated: “What this old woman told me this morning is far more important than anything I can do in my life.”3
While Hitler’s persistent stomach cramps helped spur his panic—at one point he became so convinced he had cancer that he sat down and wrote out his will—he found plenty of other causes for concern. Even his home and office were objects of suspicion: In September 1934, a physician made his way through Hitler’s Berlin headquarters with a dowsing rod, an ancient tool believed to move in response to hidden elements or forces. The rod, according to quacks of the era, could detect cancer-causing currents beneath the ground they called “Earth Rays.”4
It’s not known if the doctor detected any such “Earth Rays” that day, but whatever he found, it failed to put Hitler’s mind at ease. The next year, Hitler panicked that his persistent cough and hoarse voice were signs of throat cancer. Upon examining Hitler, a doctor discovered a polyp on his larynx. The doctor told him that it was “a very slight matter,” yet Hitler remained convinced he was heading for an agonizing death. Though he calmed down somewhat when the polyp was removed and confirmed to be benign, he summoned the same doctor again later that year, concerned about a new bout of discomfort in his throat. When the doctor failed to find anything wrong with him, Hitler remembered that there might be a more prosaic explanation: he had recently removed a thorn from his finger with his teeth and then swallowed it by mistake.5
In the spring of 1936, Hitler met the Berlin physician Theodor Morell at a social gathering and told him his stomach problems were so bad he could barely function. Morell, a bald man with a large belly who was said to sweat profusely and give off a terrible smell, was known for his odd eating habits—he bit directly into oranges rather than peeling them—and was said to sleep with his lower eyelids closed upward. He told Hitler that to be a vegetarian was no longer enough. The führer needed fresh fruits and vegetables, grown in soil treated with the proper manure. Martin Bormann, who was essentially chief-of-staff for Hitler and later was named the head of the Nazi Party Chancellery, became the de facto Reich gardener at Hitler’s mountain home in the Bavarian Alps. If Hitler was not in the vicinity, Bormann’s fresh produce was loaded onto a plane and flown to him.6
Morell also suggested an unusual treatment for Hitler’s stomach problems: pills containing a strain of bacteria that had been taken from the intestinal flora of a German military officer. The pills, known as Mutaflor, supposedly cured stomach issues and prevented cancer through interspecies warfare. The good bacteria from an Aryan officer colonized the “living space” of the colon and destroyed the bad bacteria in the process. Hitler’s own gut was now a microcosm of the entire Nazi project.
It wasn’t only Hitler. Many Nazi leaders were strangely focused on diet and cancer. Goebbels, who often turned to cancer as a metaphor in his propaganda campaigns, was also a hypochondriac and was convinced that his ulcers were signs of cancer. Rudolf Hess, Hitler’s deputy führer until he flew to Scotland in 1941, was petrified of cancer and had some of his teeth pulled in the name of cancer prevention. Hess was also passionate about organic farming and started carrying his own organic, vegetarian foods with him when forced to eat out. Hess even brought along pre-prepared dishes to meetings with Hitler at the Reich Chancellery. Hitler, annoyed, told him to cut it out.7
Julius Streicher, the Nazi official behind Der Stürmer—a tabloid so crudely anti-Semitic that even some senior Nazis were embarrassed by it—helped to establish a tumor research institute in Nuremberg. In 1936, Streicher began championing a cancer drug that could wipe out tumors with the help of extracts from Chinese rhubarb. Though a number of leading German medical figures had already dismissed Streicher’s cure as quackery, Hitler was intrigued and asked Karl Brandt, the doctor overseeing his care, to investigate the treatment. Brandt brought the researcher who had developed the new drug to Berlin and forced him to reproduce his experiments. Even when Brandt reported back to Hitler that the drug was a failure, Hitler held out hope. When Streicher continued to insist that the treatment worked, Hitler made Brandt travel to Nuremberg to investigate the matter a second time.8
Heinrich Himmler, the head of the SS and among the most powerful men in Nazi Germany, had stomach problems of his own and, like Hitler, feared that his discomfort might be an early sign of cancer. Himmler, too, suspected that diet was at the root not only of cancer but of all of Germany’s health problems. “The wrong diet always plays a decisive part in all the troubles of civilization,” Himmler once said, “from the loss of teeth to chronic constipation and digestive ailments, not to mention bad nerves and defective circulation.”
Himmler, who had studied agriculture and once worked in a fertilizer factory, focused a great deal of his energy on the role of diet in cancer. “The artificial is everywhere; everywhere food is adulterated,” Himmler wrote, “filled with ingredients that supposedly make it last longer, or look better, or pass as ‘enriched.’ ” The blame, in his view, fell on “the food companies, whose economic clout and advertising make it possible for them to prescribe what we can and cannot eat.”9
In 1933, Himmler, then the police president of Munich, established Dachau as one of the first Nazi concentration camps. The camp, situated 10 miles northwest of Munich, initially held political opponents but gradually expanded to include Jews, homosexuals, Roma, and Jehovah’s Witnesses. In 1937, prisoners at Dachau were forced to drain marshlands and then to plant and run an industrial-sized organic farm on 200 acres. The Dachau plantation eventually comprised a research station, greenhouses, a spice mill, drying and storage rooms, and an apiary from which the prisoners would harvest organic honey. The herbs and spices grown at Dachau were sold as natural remedies and are thought to have supplied nearly all of the German army’s seasonings during World War II.
The Dachau plantation quickly became the largest research center of its kind in the world. As many as 1,000 prisoners could be working in “the herb garden,” as the SS men called it, at a given time. It was among the most feared assignments; the emaciated prisoners working in “the herb garden” would regularly drop dead from exhaustion. Others were held by their feet and drowned in the carp pond.10
One of the few firsthand accounts of the Dachau plantation comes from Himmler’s young daughter, Gurdun, who toured the grounds with her family in the middle of the war: “Today we drove to the SS concentration camp in Dachau. There we then toured everything . . . the large nursery, the mill, the bees, saw how all the herbs were processed . . . all the pictures that the prisoners have made. Magnificent!” Continued Gurdun, “Then we ate, then everybody got a present. It was lovely. A very big operation.”11
Dachau was only a first step toward Himmler’s planned diet revolution. The SS had additional gardens planted at other concentration camps. In January 1939, Himmler oversaw the purchase of 16 additional farms and opened a food and nutrition institute to study “natural methods of agriculture.” That same year, the SS, already running its own fruit juice factories, began bottling mineral water.
Himmler was especially focused on what went into the mouths of his SS men. Potatoes, he ordered, should never be salted or peeled. He planned to one day bring “nutrition supervisors” into the SS who would be tasked with weaning his men off meat, among other foods. (“Too Much Meat Can Make You Sick,” reads one heading in a Hitler Youth nutrition manual from the 1930s.) Himmler appreciated that it would be a challenge to remake the German diet by replacing “meat and sausages” with “equally tasty foods that satisfy the palate as well as the body.” Soybeans, thought to be one solution to this problem, were referred to as “Nazi beans.”12
While Himmler acknowledged that some of his dietary reforms would have to wait until after the war, certain measures had to be implemented without delay: “The attention of all units must be drawn most vigorously to the toasting of bread,” he wrote to a Nazi nutrition inspector in the middle of the conflict.
Himmler’s obsession with nutrition wasn’t entirely a product of his fear of disease. Like Hitler, he dreamed of a Germany that controlled its own supply of food and could never again be starved. But cancer was never far from Himmler’s thoughts. In 1936, his father was diagnosed with stomach cancer. He died after Himmler, on a doctor’s advice, chose not to have him operated on.13
At approximately the same time, Himmler took an interest in the work of Sigmund Rascher, a Nazi medical researcher examining whether eating plants grown with artificial fertilizers might cause cancer. Rascher hoped to develop a blood test that could detect cancer at an early stage, but to figure out which blood markers might signal cancer, he would need to follow his test subjects for years. Himmler’s prisoners, it occurred to Rascher, would make ideal test subjects. On May 26, 1939, Himmler granted Rascher access to Dachau. It was in that dystopian landscape of barbed wire and organic honey that he carried out the very first medical experiments on Nazi prisoners.14
Adolf Hitler, broken glass-plate negative, date unknown.
IN THE 1930s, Otto Warburg embarked on his own war against cancer, even as his entire world unraveled around him. He had spent much of the previous decade examining cancer cells that overeat and ferment glucose. The next step seemed straightforward: Warburg would cure cancer either by preventing the switch from respiration to fermentation or by interfering with the fermentation process and starving cancer cells.
It was a perfectly logical plan but one far ahead of its time. Though Warburg had already identified the respiratory ferment, both respiration and fermentation remained poorly understood. Before Warburg could cure cancer, he would first need to return to basic science. Specifically, he would need a better understanding of enzymes, the microscopic machines that carry out the work of metabolism.
Warburg became interested in modern enzyme science only after a rapid evolution of his thinking on cells and energy. Throughout most of the 1920s, he had continued to believe that the reaction between iron and oxygen in his ferment was the entire story of respiration. Warburg had been particularly incensed by Heinrich Wieland, his first great scientific nemesis, who had argued that the key to respiration was the reactivity of hydrogen, rather than oxygen. As Warburg saw it, Wieland’s experiments, carried out on one of Ehrlich’s dyes, as opposed to on living cells, were too speculative. It was Romanticism, Warburg argued, in the process of belittling Wieland’s achievements, “to rate the unknown as more important than the known.”15
Warburg’s distrust of Wieland’s methods was sincere. A physicist’s son, Warburg always favored simple, elegant explanations for natural phenomena. The possibility that hydrogen and oxygen each had to be independently sparked into action to power life made respiration seem far more intricate than Warburg wanted to believe. Warburg had once invoked the story of the magic bullet to make a point about science, just as Paul Ehrlich had in describing his vision of targeted drugs. Only in Warburg’s telling, the seventh magic bullet goes astray and kills Max’s love because it had been hastily assembled from many different parts. The moral of the story, in Warburg’s version, was not that one should never sell one’s soul to the devil; it was that overly complicated thinking is the devil’s work.16
But for Warburg, the biggest problem with Wieland’s research was not that it was speculative or too complex. It was that the respiratory ferment Warburg had identified had not been properly acknowledged. Once that acknowledgment came in the late 1920s and Warburg felt properly validated, he would finally shift his gaze beyond his one favored molecule.
Without admitting that Wieland had been partially correct, Warburg now granted that his respiratory ferment—he still avoided the word “enzyme”—was only the last of a series of reactions that make cellular breathing possible. The process begins with the phenomenon Wieland had studied: enzymes ripping hydrogen atoms off of the fat and carbohydrate molecules that we eat. The hydrogen atoms are then stripped of their electrons, which are passed from one molecule to the next on a journey to meet oxygen at Warburg’s respiratory ferment. “Wieland and Warburg had been examining opposite ends of a great elephant,” the Cambridge biochemist Guy Brown wrote. “Wieland had the trunk where the electrons went in and stated firmly that this was all there was to the elephant; while Warburg had the tail where the electrons came out and thought this was the essence of the elephant.”17
In retrospect, it’s clear why evolution arrived at a multistep system for cellular breathing, rather than allowing hydrogen and oxygen to react. A direct reaction between hydrogen and oxygen would release too much energy at once, as the Nazis were reminded when their prized Hindenburg zeppelin turned into a ball of fire and left 36 people dead. But if Wieland and others had long appreciated that specific enzymes function like movers—taking the hydrogen from one molecule and transferring it to another—the movers themselves were not well understood.18
In his early research on respiration, Warburg had relied on indirect evidence, learning what he could from the power of cyanide and carbon monoxide to suffocate a cell. He needed a more direct approach to studying the activation of hydrogen, particularly after spending years belittling Wieland’s work. He needed, specifically, to isolate the enzymes that transfer hydrogen and to figure out what they are made of.
The task before Warburg was a bit like attempting to single out one ingredient in a smoothie made from countless unknown foods. There were no instructions to follow. Biochemists of the era would first put organic tissue through a meat grinder again and again and then pulverize the cells further until they released their “juice.” That juice, in turn, would be spun in a centrifuge to separate molecules by weight and then sent through membranes with microscopic pores to separate molecules by size. The juice might be heated or cooled or shaken or subjected to dozens of different chemical treatments, depending on the enzyme involved. Obtaining enough of any given enzyme within the “juice” might mean going through a mountain of organic matter. One visitor to Warburg’s institute in the 1930s recalled that potatoes were arriving by the ton.19
Warburg’s first success was the isolation of a hydrogen-transferring molecule that, due to its color, would later be called “Warburg’s yellow enzyme.” When Warburg filtered the enzyme through a material that allowed small molecules to seep through, something peculiar took place: the yellow component slipped away through the filter, and what remained of the enzyme lost its ability to react with hydrogen. The enzyme, Warburg saw, contained two parts: a protein and a smaller nonprotein component—the part that had been lost through the filter—known as a “coenzyme.”
Like the iron in Warburg’s respiratory ferment, the yellow coenzyme was the reactive component, the secret to the molecule’s power. Coenzymes had already been discovered, but no one could say precisely what they were made of. Anxious to determine what the yellow substance was, Warburg began a chemical analysis. What that analysis revealed brought his science to an entirely new place.
Earlier in the century, researchers had made considerable progress in identifying the specific nutrients that could prevent diseases such as rickets or beriberi. These nutrients came to be known as vitamins, but what vitamins did inside our cells to cure diseases remained unknown. Now Warburg, if only inadvertently, had arrived at an answer. The reactive yellow part of his yellow enzyme turned out to be riboflavin, or vitamin B2.
Through his quests to understand how cells breathe—and how the process goes awry in cancer—Warburg had, unintentionally, discovered why vitamins are so critical for our health. Most vitamins function as coenzymes that make respiration and fermentation possible. Because our bodies can’t produce these critical engine parts, we need to obtain them from food.
Warburg left the task of purifying and working out the structure of his yellow enzyme to Hugo Theorell, a Swedish researcher who had come to work at his institute and who would go on to win the Nobel Prize for his findings. Warburg had already moved on to another enzyme. He called it the “between ferment” because it appeared to function as a link between the hydrogen reaction that takes place at the trunk of the elephant and the oxygen reaction that takes place at the tail.
In 1933, Warburg successfully isolated the “between ferment” and saw that it, too, relied on a coenzyme. But here he ran into a significant obstacle. Warburg had relied on horse blood to study the “between ferment.” And yet 200 liters of horse blood had yielded only a few milligrams of a mysterious molecule that appeared to be the crucial reactive component. According to Warburg’s calculations, to secure enough of the substance to figure out what it was, he would have to slaughter all of the horses in Germany. Warburg, who once complained to Berlin officials that air pollution was going to give his horses pneumonia, needed a new path forward. And he needed it quickly. A group of researchers in Sweden were also making progress on the “between ferment.” When Theorell told Warburg he might travel home to Stockholm for Christmas, Warburg responded, in jest, that he would kill him if he revealed any secrets from his lab to his colleagues in Sweden. Theorell had to promise Warburg that he wouldn’t even mention the molecule.
Warburg, a scientist who let nothing stop him, was stumped. Then he got lucky. Warburg told his friend Walter Schoeller about his inability to solve the puzzle of the “between ferment.” A laboratory director at one of Germany’s major chemical companies, Schoeller regularly consulted with Warburg on his cancer research. Since Warburg already knew the melting point and molecular weight of the mystery molecule, Schoeller offered to check an industrial reference book to see if it might yield any clues. He immediately found something much better than a clue: a perfect match. The molecule Warburg sought wasn’t mysterious at all. It was nicotinamide. It had been synthesized for the first time in 1873 and was widely used in photography. “Yesterday we could not buy it for any money in the world,” Warburg said. “Today we can buy it for 2 marks a pound.”
Nicotinamide, it became clear, is the critical component of two hydrogen-transferring coenzymes—now known as NAD and NADP—that are central to both respiration and fermentation. Today, the molecules are an increasingly popular area of interest in both cancer and aging studies. Though most contemporary NAD researchers are unaware of Warburg’s contributions to the field, Theorell, who witnessed the discoveries at Warburg’s institute, was awed by him. “It is not often that such things happen,” he later said, “but let us agree that the few of us who have ever witnessed such an explosion of progress will never forget it.”20
Warburg’s research in the first half of the 1930s, which also relied on his remarkably innovative use of light absorption patterns to determine how coenzymes work, is considered by some to be his greatest accomplishment of all. It wasn’t only the breakthroughs themselves that amazed other scientists of the era, but also, as Theorell suggested, the rapid pace at which Warburg made them. As one American researcher who briefly worked at the institute in the 1930s recalled, the operation was minuscule in comparison to that of a large university research department—it consisted only of Warburg and a handful of technicians—and yet it had somehow become “the most famous biochemical laboratory of the time.”21
Warburg’s accomplishments would have been remarkable under any circumstances. But he was not working under any circumstances. He was working under a Nazi regime that was harassing him at every opportunity, questioning even his authority to order alcohol. German science was rapidly falling apart as Jewish scientists fled, and yet the Emperor of Dahlem remained at the height of his powers.
THAT A SIMPLE MOLECULE synthesized in 1873 turned out to be so central to biology was a great surprise. The bigger surprise was still to come.
In the 1920s, the American researcher Joseph Goldberger had discovered that certain foods, such as milk, eggs, and brewer’s yeast, could cure pellagra, a potentially deadly disease that leaves its victims with dry, scaly skin, fiery, inflamed tongues, and dementia, among other symptoms. “There is no more pitiful spectacle than the pellagrin,” the New York Times wrote. “Too feeble to work, he barely shuffles along.”22
Goldberger’s triumph was in convincing the medical world that pellagra was caused by something missing from the victim’s diet rather than by a microbe inside the body. (He had to inject himself with the blood of a pellagra patient before anyone would believe it was harmless.) But neither Goldberger nor any other scientist had succeeded in determining which specific molecule cured the disease.
After Warburg’s discovery that nicotinamide played a critical role in respiration, the American biochemist Conrad Elvehjem decided to investigate whether it might also be the molecule that cured pellagra. Elvehjem obtained a supply of nicotinic acid, the precursor molecule that turns into nicotinamide in our bodies, from the Eastman Kodak Company and soon confirmed that it was, indeed, the answer to the pellagra mystery.
Nicotinic acid, or niacin, is also known as vitamin B3. Warburg’s study of the molecule carries a sad irony. Though he certainly recognized the scientific importance of his work, Warburg seems never to have appreciated that his research on coenzymes was the world-changing discovery he had always hoped to make. In 1938, 400,000 people were thought to be suffering from pellagra in the American South. (Some 100,000 Americans died from the disease between 1906 and 1940.) That the little white tablets of nicotinic acid could wipe out the disease was deemed a “miracle” by the New York Times in 1939.23
Perhaps Warburg couldn’t fully recognize his accomplishment because the disease was less common in Germany. More likely, pellagra simply wasn’t a sufficiently famous disease to bestow on him the greatness and adulation he sought. Only a cure for cancer would bring the glory Warburg longed for.
Warburg continued his enzyme research after his nicotinamide triumph. During a remarkable stretch in the second half of the 1930s, he isolated and purified one metabolic enzyme after another. That research laid the groundwork for decades of future breakthroughs in biochemistry. But for Warburg, understanding how cells use energy was never an end in itself. It was also a means to understanding and curing cancer. Warburg already believed that cancer arose from damaged respiration. Having found that coenzymes were necessary for a cell to breathe, he wondered if he had also arrived at a major cancer discovery. He wondered, specifically, if feeding cells the key components of coenzymes could keep respiration humming along so that the transition to fermentation would never take place.
As early as 1934, Warburg was spreading the word that he was close to a breakthrough on cancer. At a Kaiser Wilhelm Society board meeting that year, he discussed positive results from rats injected with an unspecified “ferment,” noting that it still needed to be tested in humans. It’s possible that Warburg, already aware that his safety in Nazi Germany depended on his value to cancer science, was purposefully overstating his findings. In July 1933, Anny Schrödinger, the wife of the famous physicist, told Lotte Warburg that she had heard (seemingly by way of Max Planck) that the Nazis wanted “to keep” Warburg because of his cancer research. But an entry in Lotte’s diary at the time suggests that Warburg genuinely believed he was on the cusp of a true breakthrough. He told Lotte, in a letter, what he had told the society: that he had successfully cured cancer in rats with his “ferment” and planned to move on to human trials. “If Otto goes so far as to say he’s very hopeful then there is something to it,” Lotte wrote. “Before he would just say: ‘The cure will be found someday.’ ”
The “ferment” Warburg invoked appears to have been a coenzyme, one of the B vitamins necessary for respiration. Warburg continued to study its impact on cancer for years. A 1938 letter sent to Warburg by one of the collaborators on the experiments includes a mention of using the “ferment” to successfully cure 4 of 20 cancer-stricken animals. By that point, Warburg was trying everything.24 In one series of experiments, he subjected cancer-stricken mice to varying levels of oxygen. In another, he tested different chemicals to see if he could prevent cancer cells from getting the glucose they need in order to grow.
In retrospect, the quickening pace of Warburg’s work looks like desperation, as though he was determined to find something, anything, that would show evidence of progress. By the end of the 1930s, Warburg was isolated in Nazi Germany. The small number of Jewish scientists who hadn’t yet fled the country were now running out of time. Some would be murdered. Others committed suicide. Those who had managed to hang on to their careers were, like Warburg, Mischlinge—half-Jews and quarter-Jews. And though the fate of the Mischlinge in Nazi Germany remained uncertain, it was not hard to imagine a bad ending.