Image copyright FacePalace Image caption The skin barrier was weakened by high levels of infection and was the trigger for a response from the immune system
Long-term sufferers of an allergy to sugar are at a nearly 40% lower risk of developing the most dangerous form of blood cancer, a new study says.
It said they were less likely to develop Leigh’s syndrome and were less likely to experience early deaths.
The findings come from a study of 18 people who all had the allergy but with different genetics.
The researchers say their work could help people understand their risk of the disease.
Leigh’s syndrome causes a sudden redness, swelling and pain in the face. It has no specific treatment and is usually fatal.
About 11 in every 1,000 people have it.
Scientists at the Karolinska Institute in Sweden followed the 18 long-term sufferers – aged from 19 to 35 – for 11 years.
They found that they were 14% less likely to have any of a range of severe diseases, including respiratory infections, heart attacks, heart failure and heart attacks.
Over the 11 years, the people who had the allergy had a 26% reduced risk of the disease spreading to their bones, muscles and blood vessels.
The effect also held true for the only other major group of allergy sufferers – animals.
“At the molecular level, our results indicated a thinning of the membrane lining the mouth and tongue from prolonged exposure to sugar,” said lead scientist Professor Michal Kosloski, a virologist at the institute.
“The same thinning process continued until this was cleared out by the body’s immune system.
“The most important moment for the 18 participants was when a chronic intestinal infection, which caused severe allergic symptoms, was triggered by high levels of sugar.”
“Based on these results, we should not simply assume that patients with allergies, in general, have a lack of natural immunity,” he added.
Professor Kosloski believes these findings could be shared with clinicians and support a “careful assessment” of a patient’s genetic makeup and triggers.
If people had certain mutations in some genes, such as T-Kras, they would have less risk, he said.
Many of the genes present in people with similar behaviours to the 21st Century Dermaphilia study have previously been found in people with leukemias.
Dr Janet Clark, an immunologist from St George’s University of London, welcomed the findings.
She told BBC News: “This is a fantastic study, and a very large clinical trial. It was important to make the human health links between patients and people who had similar diseases.”
She also said that leukemias with the T-Kras gene can have different mutations to those in people with allergies, and that might be why they also tended to have a reduced risk of developing Leigh’s syndrome.
“There is no silver bullet,” she said. “It’s complex and there are really lots of genetic determinants.
“What we need now is a very large clinical trial, probably involving 100 patients, to try to identify which of the genes are contributing to which disease.”
Image copyright FacePalace Image caption Many leukemias can have variants of the T-Kras gene
Leukaemia charity Bloodwise said the findings could help prevent other cancers, but cautioned that they were still at the laboratory level.
General manager Dr Luke Williams said: “The research team has clearly provided strong evidence that there is a lower risk of Leigh’s syndrome due to a sugar allergy.
“However, patients suffering from other forms of leukaemia would not be immune to these findings.
“Clinical trials of the human blood of patients with leukaemia to see whether they have inherited these insulin sensitive genes will allow us to assess the benefits of protecting against leukaemia.”