Folic acid should be added to all bread, the Government’s food watchdog has ruled.

If approved by the Department of Health, the Food Standards Agency’s recommendation would lead to the first programme of mass medication since the FLUORIDATION of water in the 1950s.

The agency yesterday wrote to chief medical officer Sir Liam Donaldson calling for the move, following new evidence which suggests previous studies that indicated a link between folic acid and cancer were inaccurate.

Sir Liam is a strong advocate of forcing bread and flour manufacturers to include folic acid in their products and it is expected he will push the Department of Health to accept the FSA’s recommendations.

The FSA’s decision follows years of wrangling with doctors and campaigners.

In 2007 American studies indicated a link between folic acid and cancer, particularly colon cancer.

However the FSA has now decided there is not enough evidence to prove a link following an announcement by independent body the Scientific Advisory Committee on Nutrition.

The FSA said: ‘The advisory committee has concluded that the new evidence does not provide a substantial basis to change its previous recommendation for the introduction of mandatory fortification with folic acid.’

If the Department for Health accepts the recommendation, Britain will be the first EU country to follow America’s lead on folic acid. It has been added to flour in the U.S. and Canada since 1998.

Folic acid is the synthetic form of a naturally occurring B vitamin, folate. Women who have good levels of folate in their diet, or take folic acid supplements, are less likely to have babies with the birth defect spina bifida.

Spina bifida affects around 1,000 pregnancies a year and the FSA believes this number could be reduced to about 350 if folic acid was introduced into bread or flour on a mandatory basis.

Folic acid cannot be stored in the body and must be obtained from food or supplements.

In 2007, the Institute of Food Research warned that adding folic acid could increase cases of bowel cancer and trigger problems for those with leukaemia and arthritis.

It warned it might take 20 years before the effects of increased consumption by millions become known.

At the time, Dr Sian Astley from the IFR said: ‘With doses of half the amount being proposed for fortification in the UK, the liver becomes saturated and unmetabolised folic acid floats around the blood stream.

This can cause problems for people being treated for leukaemia and arthritis, women being treated for ectopic pregnancies, men with a family history of bowel cancer, people with blocked arteries being treated with a stent and elderly people with poor vitamin B status.

‘This has important implications for the use of folic acid in fortification, because even at low doses it could lead to over-consumption, with its inherent risks.’

She said it also increased the likelihood of multiple births for women undergoing fertility treatment.

A spokesman for the Department of Health said: ‘We will now consider the FSA’s recommendation for the introduction of mandatory fortification of flour with folic acid alongside controls on voluntary fortification.’