Women who consume high volumes of folic acid found in vitamin B from vegetables and some fruits are less likely to suffer from mouth cancer.
A sample of 87,000 nurses were followed for 30 years from 1976 by researchers from the Columbia University Medical Centre and Harvard School of Public Health.
Women who drank a high volume of alcohol and had low folic acid intake were three times more likely to develop mouth cancer than those who drank high volumes of alcohol but had high volumes of folic acid in their diet.
Alcohol is one of the major risk factors for mouth cancer and those who drink to excess are four times more likely to be diagnosed.
This is the first time that folic acid intake has been shown to affect the risk of the disease.
Alcohol leads to a reduction in folic acid metabolism by creating acetaldehyde which leads to a reduction of folic acid in the body.
Chief executive of the British Dental Health Foundation, Dr Nigel Carter, said: ‘Rates of mouth cancer in women have been increasing for many years as a result of changed social habits with more women smoking and drinking.
‘This new research could offer a method to reduce this by looking at the folic acid intake and increasing fruit and vegetables containing folic acid in the diet.
“In the past studies have tended to focus on males, as they are twice as likely to suffer from the disease. While this study focuses on women we know that men also benefit from the protective value of increased fruit and vegetables.’
Folic acid or vitamin B9 is essential to an individual’s health by helping to make and maintain new cells.
Pregnant women are advised to supplement their intake of folic acid, to ensure a healthy development of the baby.
Folic acid is found in vegetables such as spinach, asparagus, beans, peas and lentils and is added to bread.
Fruit juices, broccoli and brussel sprouts contain smaller amounts.
An unhealthy diet has been linked with around a third of mouth cancer cases.
Recent research has also shown that an increase in food such as eggs and fish that contain omega 3, and nuts, seeds and brown rice, which are high in fibre, can help decrease the risks.
Mouth cancer survival is poor with only around half of cases surviving for 5 years and this is due to late presentation.
Early warning signs to look out for include a mouth ulcer that has not healed within three weeks, red or white patches in the mouth and any unusual swelling or lumps in the mouth.
These are all signs that you should get your dentist or doctor to check you out as soon as possible.