Today we are all concerned about nutrition, but for a long time medical science paid no attention to this aspect.

It is surprising, but the truth is that research on the relationship between diet and health was very slow, and most of the information came from doctors who risked their lives and experimented on themselves.

Joseph Goldberger, a Jewish doctor from New York, is among them who settled in the southernmost state of America in 1914.

There, Dr. Joseph Goldberger brilliantly solved a medical puzzle that saved thousands of lives and forced governments to intervene in people's diets for the first time.

He was sent by the US Surgeon General to investigate an epidemic in the southern states of the country.

Pellagra is a very dangerous disease. Initially, it causes sunburn-like marks on the backs of the hands. After that, a butterfly-shaped sore appears on the face. This is followed by depression, confusion and memory impairment. And in 40 percent of cases, the patient dies.

Goldberger's mission was to find the cause of this disease.

An important Nuance:

The disease did not come from outside, and in households where one person had the disease, there was an 80 percent chance of contracting the disease to another person.

It was considered a highly contagious disease and its victims were treated like leprosy patients.

Goldberger had a surgeon general on his back, but as the son of immigrants, he always thought of himself as a new outsider.

Dr Alan Kraut, author of the book 'Goldberger's War', told the BBC that 'Joseph Goldberger was deeply influenced by the American West and Westerners throughout his life. And much of his medical research work and his fight against the epidemic was another form of his desire to be an adventurer who wanted to achieve something worthwhile.'

"He saw himself somewhat as a lone hunter with only scientific bullets," said Dr. Don Sharp, Goldberger's grandson.

 Goldberger toured the southern states of the United States and visited prisons, orphanages, and nursing homes to learn about the disease.

And there they saw a surprising thing that the prisoners were being affected by pellagra but not the prison staff.

So while most of his colleagues were of the opinion that it was an infectious disease, he realized that it was not, but something else.

They soon came to the conclusion that something in the diet was causing the pellagra.

But Goldberger knew that as a northerner, if he criticized the food of the southern states, no one would listen to him.

"They needed evidence for scientists to support their conclusion that pellagra was not actually a disease, but a food-related illness," says Dr. Alan Kraut.

So they thought of doing a very controversial experiment.

They decided to inject pellagra into 12 perfectly healthy men.

And these 'volunteers' were inmates of a prison in the state of Mississippi.

Back then, most people, especially the poor, only ate what was considered a southern delicacy. This food, called lardo or fatback, is made from lard, grains and molasses, i.e. syrup.

At first the men thought it was too great, but after six months all the prisoners started showing symptoms of pellagra, so Goldberger ended the experiment.

He was now fully convinced that improper diet was the cause of pellagra.

But the scientific community still disagreed with him.

Goldberger was shocked. To silence his critics and prove his point beyond doubt, he decided to do something even more controversial, experiment on himself.

He wrote: 'I did not impose any restrictions. No effort was made to prevent 'natural infection'.

First, he went to a local pellagra hospital and there he took a swab and collected colds from the patients' noses and put them in his own nose.

He wrote: 'There was less than two hours between collecting the samples and inserting them. By the way, perhaps it should be remembered that some cold that is put in the nose may have been swallowed in the end.

They then collected urine, skin samples, and stool.

He wrote: 'The patient who provided me with stools had severe seizures and passed watery stools four times a day.'

Dr. Goldberger mixed all these ingredients with wheat flour, made a pill and swallowed it.

Dr. Alan Kraut says that 'the thought of ingesting someone's skin and faeces can make you feel sick.'

Dr Sharp said: 'We as a family have always found it unbelievable how he could have put himself in such danger. Often when we talk about it with our family and friends, we are left dumbfounded.

Goldberger also asked his colleagues to join in the experiments, which he called 'dirt parties'.

And if feces and urine weren't enough, Dr. Goldberger had one last surprise for them: blood.

He collected some blood from a patient and transfused all his volunteers, including his wife Mary.

Dr Sharp says: 'I think my grandmother wanted to do anything to silence those critics.'

Mary says: 'The men did not allow me to swallow these pills, but they injected me in the stomach with the blood of a woman dying of pellagra.'

Any type of germs could enter their body through this needle.

Mary said: 'It was trust, I didn't need bravery.'

Marie's faith paid off and none of the volunteers got sick.

Dr Sharp said: 'My grandfather was very excited and delighted that none of the people who attended the dirt parties had contracted any illness other than mild diarrhoea.'

And no one had pellagra.

Goldberger thought he had done it. They had all the evidence to prove that pellagra was not a contagious disease. This was due to the lack of an important element in the diet of the southern region.

His case had become completely bulletproof and now it was time to go public and wrap up.

But he had to face severe and violent criticism from the southern people.

Goldberger realized that he would not be able to convince doctors that pellagra was caused by a dietary deficiency until he found a cheap and simple treatment.

And this discovery also happened in an interesting way.

They were experimenting with pellagra by feeding dogs southern food, but the problem was that the dogs did not want to eat the food.

So they added to their diet what they termed 'appetizers'.

Several months passed but the dogs were still healthy. Goldberger eventually learned that this appetizer was keeping him safe. Perhaps this was what they had been looking for for years.

And here's the thing. It is no meat, no vegetable, no mineral, but only yeast.

In 1927, Goldberger's time finally came. After the floods, pellagra spread further. Goldberger provided yeast to the refugees.

It was surprising that people started to recover after taking a few teaspoons daily.

Goldberger was eventually hailed as a hero.

Years later, a chemist discovered something from yeast that helped prevent pellagra. It is a vitamin called niacin.

The US government ordered flour mills to add niacin to flour. Other countries followed suit and pellagra soon became a disease of the past.

We now know that niacin is essential for healthy skin, digestive system and nervous system.

Goldberger proved a close connection between diet and health. Our diet and lifestyle are directly related to our diseases and this is what Dr. Joseph Goldberger wanted to explain to the world.