Scientists dispute safety claims

Food Safety Minister Kate Wilkinson has been caught up in a row among scientists about whether folic acid increases the risk of cancer.

Wilkinson told TVNZ's Close Up programme earlier this week that she was convinced dosing bread with folic acid was safe, based on data from an as-yet unpublished British study.

She also attacked Food and Grocery Council chief executive and former National MP Katherine Rich and Green MP Sue Kedgley, calling them "irresponsible" for "alarming New Zealanders, when the science says there is no risk".

Wilkinson made the claim following a telephone conversation with University of Otago Professor Murray Skeaff, who had issued a statement saying new research presented at a conference he attended in Prague showed there was no increase in cancer risk with high-dose folic acid.

Skeaff said the data was "state of the art" and the highest-quality analysis to date that folic acid posed no risk of cancer.

But two other professors who were at the same conference have disputed Skeaff's claims, and say he omitted to mention a Norwegian study presented to the meeting, which found an overall increased risk of cancer in two trials including deaths. They also point out the Prague conference voted by majority to oppose mandatory fortification of foods with folic acid.

Oxford University Emeritus Professor David Smith said Skeaff's account of the meeting was "outrageous" and failed to mention the study to which he referred was only set up to detect an increase in cancer rates of greater than 10 per cent.

"So it does not exclude a rise in cancer below 10 per cent, which is a lot of people if the whole country is exposed.

"He did not mention the Norwegian study, which caused much more interest, which showed an overall increase in cancer in two combined trials with longer follow-up and an increase in cancer mortality," Smith said.

University of Oslo Professor Helga Refsum said she found it disconcerting that Skeaff did not report the overall vote of the conference against folic acid fortification.

"It would be good if Dr Skeaff had reported those views as well.

"The specialists are concerned. The meta-analysis data and all the other data coming in are not convincingly negative [i.e. indicating no ill effect], in contrast to what Skeaff has tried to say," she said.

Skeaff, who has also provided advice to Food Safety Australia New Zealand and the Ministry of Health on the plan to put folic acid in bread, said yesterday he stood by his comments. He told The Press he had never claimed the information he provided was the view of the whole conference, but was simply his interpretation of the data that was presented.

"You have to make a decision sometimes and that was my interpretation.

"Clearly Drs Smith and Refsum don't agree with me."

Skeaff said it was "a reasonable point" that the study did not test below a 10 per cent risk for cancer, but said the trials were actually set up to look at the impact of folic acid on cardiovascular disease.

Wilkinson said in Greymouth yesterday that she had not changed her stance on folic acid presenting no risk, but she would study the results of the conference when they were published.

"We are always open to scientific studies and updates," she said.

A spokesman said Wilkinson had spoken to Skeaff to assure herself about the new study before going on Close Up.

"She said to him `I am about to go on and if I am asked if this is absolutely safe, what do I say'? He said `yes'.

"She was looking for that confirmation and he provided that confirmation."

The Paediatric Society of New Zealand and the Royal Australasian College of Physicians said yesterday they "strongly support" mandatory fortification of bread.

- © Fairfax NZ News