A chemical found in peanuts may be an effective treatment for tuberculosis, research suggests.
Peanuts contain the crucial chemical
TB causes the death of more than two million people world-wide each year.
However, most who are exposed to the bacterium that causes the disease show no ill effects.
This suggests that in most cases the immune system is strong enough to prevent the bacterium from causing disease.
The chemical nitric oxide (NO) is thought to play a key role in mobilising the body's defences.
And scientists believe it is a deficiency of NO that makes some people vulnerable.
Many nuts contain a lot of arginine but peanuts are especially rich in this nutrient
In theory, boosting NO levels could correct the problem.
One way to do this is may be to give people capsules of a substance called arginine, which is used by the body to produce NO.
Arginine is found in particularly high concentration in peanuts.
Scientists from Linkoeping University in Sweden tested the theory in a study involving 120 patients with TB in Ethiopia.
The volunteers were given either arginine or dummy capsules for four weeks alongside standard drug therapy.
Those given arginine responded more quickly to their treatment.
Symptoms such as serious coughing cleared up more rapidly, and spit tests showed a lower level of TB bacteria than those who took a placebo.
The researchers believe that arginine therapy could reduce the length of time that patients have to take standard drug treatments.
They believe it might even reduce the risk of transmission during the infectious stages of TB.
Lead researcher Dr Thomas Schön told BBC News Online: "It is important to emphasize that the four-drug antibiotic regimen recommended by the WHO is the most important way of treating TB.
"However, arginine supplementation might represent a new therapeutic option to make this treatment more effective initially by boosting the immune response through increasing nitric oxide production."
In areas where arginine capsules are not readily available, the researchers suggest that people could get much the same positive effect from eating foods - such as peanuts - which are arginine-rich.
Dr Schön said: "Many nuts contain a lot of arginine but peanuts are especially rich in this nutrient and are cheap and available around the world.
"Peanuts also contain other nutrients as well such as fat, which might also give other, but possibly positive effects for the patients."
Dr John Harvey, of the British Thoracic Society, said: "This is interesting research which needs further exploration.
"It reinforces other evidence that a balanced diet rich in fruit and vegetables - may help to protect against the development of many lung diseases that are associated with inflammation - such as asthma and TB."
The research is published in the European Respiratory Journal.