New research claims that the use of nitrate fertilisers in growing vegetables could be the cause of the fastest growing cancer in the UK, reports BBC Online.
Researchers have studied the link between nitrate-rich fruit and vegetables and gullet cancer, which kills more than 3,000 people in the UK every year.
The study is being led by Professor Kenneth McColl at Glasgow University. He says the cancer affects three times as many men as women, and cases have trebled in the last 20 years.
Nitrates occur naturally in fruit and vegetables but the use of extra fertilisers began in the 1940s when the war demanded maximum output. Although permitted levels of nitrates have fallen since then, research shows that the rise in gullet cancer follows the same curve as the use of the fertilisers but with a 10 to 20 year time lag.
McColl's team have studied the link between high levels of nitrate and cancer around the gastro-oesophagael junction, where the oesophagus joins with the stomach.
The team now plans to carry out further tests on humans in a bid to find out the extent of the problem, which appears to affect people in Scotland more than any other part of the UK.
McColl said: "We are still carrying out this study and are certainly not saying people should stop eating vegetables. But our investigations have shown that there is definitely something happening here."
"Hopefully, with further human tests, we will be able to see exactly how and why this is taking place because at the moment it is a mystery, but one that is having severe consequences."
He revealed that this form of gullet cancer was now more common than stomach cancer in the UK and noted that some victims had been aged as young as 30, with a number of sufferers dying within a few years of being diagnosed.
His team, which has received a £150,000 grant from the Scottish Executive to carry out the study, has found that human saliva plays a vital role in converting nitrates into carcinogens, which come into force at the gastro-oesophageal junction.
The researchers believe that this form of cancer may be prompted in some people at the point when the saliva they swallow first meets the acidic juices in the stomach.
Furthermore, countries with less sunlight which grow the majority of vegetables under glass, such as the UK, are more at risk.
McColl also said organic food would not prove to be a healthier option because it also contained substantial levels of nitrate, some of which came from natural fertilisers such as manure.
"It appears that the mass production of vegetables in the western world since the last world war may be the underlying factor that has led to such huge increases in this form of cancer," the professor said.
"We now want to determine if the permitted levels of nitrate fertilisers, which has fallen somewhat in recent years, may be partly to blame."
He said research so far had showed that green and root vegetables contained the highest levels of nitrate.
In the last 20 years, the number of people suffering this form of cancer in Scotland alone has risen from 450 to more than 1,100, the professor said.