In more evidence that messing with nature can have negative health consequences, a new study from Seattle's Fred Hutchinson Cancer Research Center has confirmed that synthetic folic acid supplementation may increase the risk of colorectal cancer.
This conclusion was determined using the Women's Health Initiative Observational Study, which included 88,045 postmenopausal women who were tested and studied between 1993-1998, just following the mandated folic acid supplementation requirement in the United States.
Most of the folate supplementation to foods utilizes synthetic folic acid, rather than nature's molecule, referred to as folate (though many incorrectly refer to folic acid as folate).
The research found 1,003 colorectal cancer incidences among the study population as of 2009. When nutrient consumption was analyzed, the researchers found that those women in the top quarter of folic acid consumption had higher incidence of colorectal cancer between three an nine years after the folic acid mandate.
The researchers could not determine whether the cause was too much supplementation or due to the supplement being the synthetic form of the nutrient. The two are indelibly tied, however, because a healthy diet that supplies the natural form of folate has been connected with reduced cancer incidence.
Other research has found that high supplementation of synthetic folic acid can increase malignant tumor proliferation and increase cancer risk in general.
The folic acid mandate was instituted in 1995 in order to combat a series of birth defects in children, including spina bifida and other neural tube issues. The fortification requirement came from the U.S. Food and Drug Administration, which required 40 micrograms of folic acid be added to every 100 grams of grains and flours, including noodles, pasta, corn meals and other refined grain products. In 1998, the FDA added the folic acid fortification requirement to breads, cereals and other foods that contained refined flour.
Whole grain flours and foods do not require folic acid supplementation because they already maintain natural folate content.
Research has found that spina bifida and other defects may be reduced up to 70% should women of child-bearing age consume at least 400 micrograms of folic acid per day.
Now the research is showing there is a price to pay for the extensive folic acid supplementation by women. Increasingly, nutritionists are warning against folic acid supplementation over 400 mcg per day. Pregnant women are often advised to double this dose, to 600-800 mcg per day.
Too much folic acid supplementation can also mask a vitamin B12 deficiency.
Folate and folic acid are also called vitamin B9. The natural form, folate, can be found in a large number of natural, unprocessed foods, including most leafy green vegetables including romaine lettuce and broccoli; many fruits including citrus, banana, raspberries, cantaloupe, honeydew; peas; beans; beets; seeds including sunflower seeds; and many whole grains including whole wheat and oats. Most nutritionists agree that a whole-foods, mostly raw diet with plenty of these foods, will supply sufficient folate. For those with a questionable diet, there are whole food supplements available that produce natural folate.
In addition, certain probiotic bacteria naturally produce folate, which include Lactobacillus plantarum, Bifidobacterium adolescentis and B. pseudocatenulatum.
The research by the Fred Hutchinson Cancer Research Center also found that other B vitamin supplementation reduced colorectal cancer incidence. These included vitamin B6 and ribloflavin. Both of these B vitamins are also available in whole foods and also supplied, to a marginal extent, by probiotic bacteria.
- Zschäbitz S, Cheng TY, Neuhouser ML, Zheng Y, Ray RM, Miller JW, Song X, Maneval DR, Beresford SA, Lane D, Shikany JM, Ulrich CM. B vitamin intakes and incidence of colorectal cancer: results from the Women's Health Initiative Observational Study cohort. Am J Clin Nutr. 2012 Dec 19.
- Rossi M, Amaretti A, Raimondi S. Folate production by probiotic bacteria. Nutrients. 2011 Jan;3(1):118-34.
- Williams LJ, et al. Status of Folic Acid Fortification in the United States. Pediatrics 2005; 116; 580-586.
- Strickland KC, Krupenko NI, Krupenko SA. Molecular mechanisms underlying the potentially adverse effects of folate. Clin Chem Lab Med. 2012 Dec 12:1-10.