Controversial piece on Folic Acid in LA Times

Credited with lowering the rates of some birth defects, the vitamin also has been linked to a higher likelihood of some cancers. By Emily Sohn, LA Times

May 11, 2009

Excerpts:

Folic acid is one of those great public health success stories. In the decade that followed the fortification of cereal grains and other foods, along with educational campaigns, the rate of certain birth defects dropped dramatically.

There is now an urgent need, experts say, to figure out how much folate is enough but not too much for different segments of the population.

"Too little folic acid we know is not good, and too much folic acid is probably not good," said Connie Motter, a genetic counselor at Akron Children's Hospital in Ohio and co-chair of the National Council for Folic Acid, a coalition of advocacy groups. "The answer is not going to be easy."

The United States began requiring the fortification of flour, and several other cereal grains in 1998, after clinical trials linked folic acid deficiency with spina bifida and anencephaly, two potentially devastating birth defects. Since then, the rate of both defects has declined by 20% to 50%.

No one disputes the need for women to have adequate amounts of folic acid in their bodies at the time of conception. The first few weeks of pregnancy, in particular, are a critical period for a baby's brain and spine development. And because more than half of pregnancies are unplanned, doctors recommend that all women of childbearing age take a daily supplement of up to 800 micrograms of folic acid.

But for other people, the evidence for folate's benefits is mixed.

On the plus side, getting enough folate protects against anemia. It may promote heart health, though that link is controversial. And it keeps hair, skin and nails healthy.

On the downside, scientists know that excess folic acid can cover up a shortage of the vitamin B12. B12 deficiency is a common condition in older patients that can cause dementia if not addressed.

The story grows even more complex in the case of cancer.

"For the last 20 years, I've been publishing papers and doing research that demonstrates that if you don't get enough folate, you have a higher risk for several types of cancer," said Joel B. Mason, professor of nutrition science and policy at Tufts University in Boston. "More recently, what has emerged is that it's not as simple of a relationship as we thought."

In some ways, folic acid appears protective. The vitamin plays an essential role in the formation and repair of DNA and can help prevent development of certain cancers, particularly in the colon, where cells replicate especially fast.

Studies show that people who get plenty of folic acid reduce their risk of developing colorectal cancer and precancerous polyps by 40% to 60%. But folic acid doesn't just help healthy cells grow. It also helps cancerous cells grow.

"We're presented with this horrible dilemma that on the one hand, taking ample quantities of folate in the diet is helpful. On the other hand, it might be accelerating the risk of developing certain cancers in certain people."

And so governments face a tricky problem: how to make sure that the people who need folic acid are getting enough without putting another segment of the population at risk. More than a dozen countries currently have mandatory folic-acid fortification. Many others are considering it, including the European Union.

Several years ago, the March of Dimes was pushing for higher levels of fortification, but the organization is now supporting current levels.

"Do we know whether the risk to an adult male is the same as the risk to a woman in her childbearing years?" she said. "The answer is no. . . . There is always a risk and balance with anything you do."

Steve - interestingly enough, these two studies came out the day after this piece was published:

Folic acid food rules cut birth defects

Fortifying flour and pasta products with folic acid appears to cut the number of babies born with congenital heart disease, the most common of all birth defects. While food fortification is not mandatory in Europe, a 1998 Canadian requirement has led to a 6 percent drop each year in the number of such defects in Quebec, they reported in the British Medical Journal.

Currently 67 countries fortify wheat flour, 47 of them by mandate, Helena Gardiner of Imperial College in London and Jean-Claude Fouron of CHU Sainte-Justine University Hospital Center in Montreal noted in an editorial.

Even with fortification, many women do not get enough folic acid. In their study, Pilote and colleagues identified all infants born in Quebec with severe congenital heart defects between 1990 and 2005.

Their analysis showed no change in how many babies were born with severe heart defects in the nine years before fortification. But there was a 6 percent decrease annually for each of the seven years after fortification began.

A pre-pregnancy year of folic acid sharply lowers risk of very premature birth

Taking folic acid supplements for a year before conception reduces the risk of very premature birth by at least 50%, researchers reported Monday.

Shorter courses of the supplement were not as effective, according to the study of nearly 35,000 women reported in the Public Library of Science journal PLoS Medicine.

Folic acid's effectiveness in reducing the risk of neural-tube and other birth defects -- even without such a long course -- is long established. The discovery that it can also reduce the risk of preterm birth "is very significant," said Dr. Diane Ashton, deputy medical director of the March of Dimes Birth Defects Foundation, who was not involved in the study.

The finding reinforces the recommendation that "all women of child-bearing age should take multivitamin supplements," she said.

Only 35% to 40% of such women do take supplements, according to surveys conducted by the March of Dimes and other groups.

The researchers found that for women who had been taking folate for at least a year before conception, the risk of birth between 28 and 32 weeks was reduced by 50%.

The risk of birth between 20 and 28 weeks was reduced by 70%.

The latter reduction is particularly significant, Ashton said, because researchers had previously found no way to reduce the proportion of preterm babies born so early.

Other recent research in the last two months:

Folic Acid Before Conception Boost Birth Weight

Folic Acid Improves Migraine Relief

Folic Acid May Suppress Allergies

So where are we with folic acid you ask?

1. It is crucial that fortification of the food supply continues.
2. As we have exhaustively explored as the research has periodically come out with regard to the colorectal cancer, the data is highly malleable depending on interpretation. Hence, the jury is still out.
3. As with any nutrient, dosage is based upon individual need. This is definitely the case with folate.
4. One component of folate research that is copious, but rarely mentioned by public health officials and the media concerns genetic predisposition. Roughly 25% of the human population has the inability to break down folic acid into its absorbable folate form. This must be taken into account when doing any research associated with folic acid and cancer.