Even by his own standards, Hitler's hatred of smoking was extraordinary. Braun, Joseph Goebbels and the other unfortunate addicts who shared a roof with the Fuhrer in the last days of the war had to sneak out into the smouldering ruins of Berlin for a few furtive drags. Braun covered up her guilty secret by chewing mints.
Half a century later this first smoking ban at a public place seems enlightened, at least from an American perspective. A US scholar has assembled compelling evidence to prove that, largely because of Hitler's obsession, not only the bunker but wartime Germany as a whole was at least 20 years ahead of the rest of the world in nailing tobacco as the cause of lung cancer and in attempts to curb the filthy habit.
The implications are enormous. Millions of people puffed on after the war, oblivious to the dangers. On proper medical advice, some might well have given up smoking and lived a good few years longer.
A reappraisal of German medical science is also in order. The experiments of Josef Mengele and his ilk debased the work of an entire generation of German scientists. It has been assumed no worthwhile work was done by Third Reich biologists, so tainted were they all by their search for racial purity and related pseudo-science projects. The Nazis could build rockets - curing human ailments was not their forte.
The historian Robert Proctor, author of The Nazi War on Cancer, explodes that myth, only to raise more questions: how did the knowledge gathered in the Third Reich become lost, and why did it take the medical establishments in Britain two decades and in the US even longer to rediscover it? Or did they know it all along?
First, the evidence. It all goes back to the day the young Adolf Hitler chucked his last packet of cigarettes into the Danube. Smoking, he decided, was bad for him, and therefore bad for Germans. Tobacco was one of the first things he would try to wipe off the face of the Earth.
Soon after he reached power, millions of posters proclaiming nicotine as "poison for the Aryan race" were printed. Measures were promulgated, restricting the sale of cigarettes to women, cutting soldiers' rations on the Eastern Front and banning smoking in cars, trains and buildings. Members of the Hitler Youth were drafted in to spread the message with their inimitable subtlety.
At the same time, money was poured into research. A link between rising consumption of alcohol and tobacco and the incidence of stomach and lung cancers had long been suspected. The first breakthrough came in 1939, when a PhD student at Cologne University demonstrated for the first time a connection between smoking and lung cancer. In 1942 Hitler helped to set up the Institute for the Struggle Against the Dangers of Tobacco at Jena with 100,000 Reichsmarks from his own budget.
A year later the Jena scientists came up with the goods. Two researchers, Eberhard Schairer and Erich Schoniger, had carried out a statistical analysis of the correlation between tobacco and lung cancer, using a group of smokers as well as a control group.
Their study, described by Professor Proctor as the "crown jewel of 20th- century epidemiology", established that smokers ran an increased risk of lung cancer.
To put this finding into perspective, Britain's Medical Research Council claims to have been the "first national institution in the world to accept formally the evidence that tobacco is a major cause of death". The research council took that leap of faith in 1957.
Germany did not just investigate, it acted on its findings. As early as 1939 the Nazis convened a congress on the dangers of tobacco, attended by 15,000 scientists. In the same year Hermann Goering forbade soldiers from smoking on marches, in the streets or on patrol. Cigarettes could not be sold to women, drivers faced lawsuits for criminal negligence if found smoking at the wheel. Research continued, with mixed success. Hitler was convinced of tobacco's lingering genetic effects.
But scientists did not dare to report the results of their fertility studies, which showed that nicotine was, if anything, making laboratory rats more randy. Like the rest of German life sciences, much of the tobacco research was motivated by the Nazis' preoccupation with "racial hygiene" and inevitably ended up in blind alleys. Stomach cancer also drew a blank. But the rest of their research has stood the test of time. "If it hadn't been for the war and the fact that this research had ideological grounding, the Jena study would be considered a classic early epidemiological work," said Professor George Davey-Smith of Bristol University, who was the first to unearth this piece of the jigsaw. "I think it was underestimated."
What a pity it all became lost. Or did it? German in those days was the language of science, its scholars well enough respected - prejudices and distaste notwithstanding - to elicit academic curiosity among its competitors elsewhere in the West. Their work was published by reputable journals. Even Mengele's disgusting research on human guinea-pigs in Auschwitz and the inquiries German scientists were conducting at Buchenwald appeared in print.
"It's extraordinary what was in the medical journals of the time," said Professor Paul Weindling of Oxford Brookes University, a leading expert on Nazi eugenics research. "And the British and Americans would just read them."
They did not own up to it, of course. The international scientific community did not want to get mixed up with the unethical work of German colleagues, and therefore created the myth that all German medical science had been paralysed by primitive racism. "There is no doubt that there were some really mad scientists involved, but on the other hand you have to look at the people who used the opportunities available to do very advanced work," said Professor Doris Kaufmann.
The German historian leads a group in Berlin which is going through the archives of Germany's elite research institutes. What they have discovered so far is that many scientists employed on Goering's human projects were considered good enough to be given jobs in the United States after the war.