Folic Acid: Too Much of a Good Thing?

If you believe everything that your read in the media or hear on those infomercials, you would think that you should spend all day munching pounds of fruits and vegetables while taking megadoses supplements chasers.

While that may sound good in theory, in practice things are not so simple and this approach may actually do you harm.

A good example has just come to light in a report from the Institute of Food Research in the United Kingdom that has just been published in the British Journal of Nutrition.

We have talked before about the potential value of fortifying food with folic acid. Apart from reducing the risk of neural tube defects in babies, it may also reduce the risk of depression.

The new report suggests that fortifying flour with folic acid may lead to a range of health problems.

Folic acid is a synthetic form of folate, a B vitamin found in a wide variety of foods including liver and leafy green vegetables. Folates are metabolized in the intestine, whereas folic acid is metabolized in the liver. The liver is an easily saturated system, and at doses of half the amount being proposed for fortification that could lead to significant unmetabolized folic acid entering the blood stream.

This excess folic acid could cause a number of problems:
It may interfere with some treatments for leukemia and arthritis
Women being treated for ectopic pregnancies
Men with a family history of colon cancer
People with blocked arteries being treated with a stent
In women undergoing in-vitro fertilization, it may increase the likelihood of conceiving multiple embryos
Unmetabolized folic acid accelerates cognitive decline in the elderly with low levels of vitamin B12 (If they have normal levels of B12, folic acid may slow brain aging)
While dietary folates have a protective effect against some cancers, folic acid supplementation may increase the incidence of colon cancer
Folic acid may increase the incidence of breast cancer in postmenopausal women, though other studies have shown the opposite

The trouble is that it could take 10-20 years for any potential harmful effects of unmetabolized folic acid to become apparent.

The latest study follows a letter to the Food Standards Agency from Sir Liam Donaldson, the Chief Medical Officer of England, requesting further expert consideration of two recent studies linking folic acid to bowel cancer before the government gives the final go-ahead for mandatory fortification of food with folic acid. However the Food Standards Agency has stuck to its position that fortification is safe. Mandatory fortification has already been introduced in the US, where it has been required since 1998, Canada and Chile, where it has cut neural tube defect rates by up to half.

Professor Nicholas Wald, director of the Wolfson Institute of Preventive Medicine, said:

“Fortification would prevent many cases of spina bifida and would also benefit the health of the country as a whole. Further delay in this public health measure will result in hundreds more babies being disabled by this serious disorder, or pregnancies being needlessly terminated due to a neural tube defect.”

When it comes to analyzing risks and benefits, one of the most important things is to realize that more is not necessarily better, and that folate and folic acid are not the same thing at all.

Second is the point that we discussed before: some people have the right genes to be able to metabolize folic acid with impunity, while others may get a range of problems from taking it.