Mandatory fortification of flour with folic acid will prevent only a small percentage of birth defects but could pose long-term health risks, it has been claimed.
Mark Lawrence, an expert on folate fortification, believes a proposal by Food Standards Australia New Zealand (FSANZ) to add folic acid to all bread-making flour, is premature and constitutes a "population-wide experiment".
Dr Lawrence, a senior lecturer in the School of Exercise and Nutrition Science at Deakin University, said it was well documented that folic acid supplementation reduced the rate of birth defects such as spina bifida.
But the level of fortification proposed by the food regulator (approximately 200 micrograms of folic acid per 100 grams of flour) would reduce neural tube defects by an average of only 8 per cent - or 26 conceptions - a year.
Meanwhile, an entire population, not just women of child-bearing age who were the target of the proposal, could be exposed to potential health risks, he said.
Dr Lawrence, who wrote his PhD thesis on folate fortification, said two recent research papers had suggested potential links between raised folate levels and an increased risk of certain cancers, including colorectal and breast cancer.
One paper, published in the British medical journal Gut, concluded that the "possibility of a detrimental component to the role of folate in carcinogenesis (the formation of cancers) could have implications in the ongoing debate in Europe concerning folate fortification of foods".
Dr Lawrence said there were also concerns that high levels of folic acid could mask vitamin B12 deficiency, particularly in the elderly - leading to neurological damage.
The food regulator's own assessment of the safety of the proposal acknowledges that "it cannot be concluded that mandatory fortification is completely without health risks".
In a paper released this week, FSANZ noted there were "uncertainties associated with mandatory fortification, particularly chronic exposure to increased folic acid intakes beginning in childhood".
However, the regulator's chief scientist, Marion Healy, said the benefits of adding folic acid to bread far outweighed any potential risks. Dr Healy said there was no conclusive evidence linking raised folate levels with an increased risk of cancer, indeed many studies had suggested it might be protective.
"Certainly, it's not possible to say that there is an established link between folate intake and cancer," she said.
Nevertheless, the food regulator had taken a cautious approach and proposed a very low level of fortification, she said. Women planning a pregnancy would still need to take a folic acid supplement. Any potential adverse health effects of fortification would be closely monitored.
About 300 to 350 pregnancies in Australia each year are affected by neural tube defects, and about 70 per cent of these are terminated. Women of child-bearing age can reduce their risk of conceiving a baby with a neural tube defect by taking 400 micrograms of folic acid daily before and during the first three months of pregnancy. But it is estimated that as few as one in three women do so.
Dr Lawrence said that as 92 per cent of neural tube defect conceptions would not be prevented by fortification at the levels proposed, more effort should be made to ensure women of child-bearing age took folic acid supplements.
"When you start thinking that the effectiveness is only going to be 8 per cent and FSANZ acknowledge we're going to have to promote supplements anyway, and there are all these potential risks," he said.
"I just struggle to see how we can support mandatory fortification as an approach. Why don't we invest in a supplementation program (instead)?"
But Professor Fiona Stanley, a strong advocate of the proposal, said that programs to promote folate supplementation had failed. Voluntary fortification of some foods, in place since 1995, had not gone far enough.
She said the women most at risk of having a baby with a birth defect - Aboriginal women, women who smoke, young women and those whose pregnancies were unplanned - were the ones not getting enough folate.
"If you don't now mandatorily fortify, you're denying those women who are the most vulnerable in our community the opportunity to reduce their risk of having a baby with a major birth defect," she said.
Professor Stanley, the director of the Telethon Institute for Child Health Research at the University of Western Australia, said it was a question of human rights.
I have sent Dr. Mark Lawrence the following e-mail. I wonder if I get a response?
I read an article in the Age the other day that quotes you as saying: "folic acid supplementation reduced the rate of birth defects such as spina bifida." and "two recent research papers had suggested potential links between raised folate levels and an increased risk of certain cancers, including colorectal and breast cancer."
Can you please point me in the direction of these papers? Both my partner and I are planning on pregnancy in the near future and we BOTH take a 5mg Megafol tablet each morning, She to decrease the risk of neural tube defects and I take it to keep my homocysteine levels in check.
Should I be concerned about the alleged increased risk of various cancers?
UPDATE 1: I received an "out of office" response to my e-mail. Dr. Lawrence will be back at work on Tuesday the 25th of July. Hopefully I'll get a response then.
UPDATE 2: I received a reply from Dr. Lawrence. It seems the good doctor is still at work, even though he's not in his office.
The references for the two papers that you ask about are:
Guelpen, B. Hultdin, J. Johansson, I. Hallmans, G. et al. Low folate levels may protect against colorectal cancer. Gut, 2006,
Stolzenberg-Solomon, R. Z. Chang, S. C. Leitzmann, M. F. Johnson, K. A, et al. Folate intake, alcohol use, and postmenopausal breast cancer risk in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Am J Clin Nutr, 2006, 83: 895-904. (The American Journal of Clinical Nutrition. Unfortunatly, I'm not a member so I can't read the paper.)
Please speak with your doctor for their advice on using folic acid supplements - certainly there is strong evidence that folic acid supplements are associated with reduced risk of neural tube defects.
From the above paper .....
"Conclusions: Our findings suggest a decreased CRC (colorectal cancer) risk in subjects with low folate status. This possibility of a detrimental component to the role of folate in carcinogenesis could have implications in the ongoing debate in Europe concerning mandatory folate fortification of foods."
The debate is happening in Australia too!