London :A natural compound, found in citrus fruits, could help in early-stage detection of liver diseases, according to a new study.
The natural compound limonene occurs in the greatest abundance in citrus fruits, but it is also found in a large variety of other fruit and vegetables.
In the UK alone, liver diseases have risen sharply over the past few decades and is the third biggest cause of premature mortality, with three quarters of liver deaths due to alcohol poisoning.
Patients are often not diagnosed till the advanced stage. Even then diagnosis is difficult and the symptoms and signs are often mistaken for other pathologies.
The study by Molecular Physics Group was carried out in two phases breath samples from a group of 31 patients suffering from cirrhosis, a condition in which the liver does not function properly due to long-term damage, were first compared with a healthy control group.
Then pre-transplant samples from cirrhosis sufferers were compared with a sub-cohort of 11 patients who went on to have a liver transplant.
When the patients were tested before transplant surgery, the level of limonene in the breath was found to be very high higher than in a healthy person. This resulted from patients being unable to fully metabolise limonene.
When the team tested the same patients who had received a new liver, the tests showed that the limonene levels gradually dropped over several days.
The researchers deduced that the unmetabolised limonene had been stored in the body fat of people suffering with cirrhosis.
Dr Margaret O’Hara, primary investigator of the group, said: “We already knew that people with liver disease have a very distinct smell on the breath and we wanted to find out what caused that smell. Now that we have found a biomarker for the disease in limonene, we can continue to verify how good it is for diagnosing liver disease.”