Researchers probe risks, benefits of folic acid fortificationJuly 10, 2007Friedman Nutrition Notes BOSTON - Since the institution of nationwide folic acid fortification of enriched grains in the mid 1990s, the number of infants born in the United States and Canada with neural tube defects has declined by 20 percent to 50 percent. Concurrent with the institution of fortification, however, the rate at which new cases of colorectal cancer were diagnosed in men and women increased, report researchers at the Jean Mayer USDA Human Nutrition Research Center on Aging (USDA HNRCA) at Tufts University. Joel Mason, MD, director of the USDA HNRCA's Vitamins and Carcinogenesis Laboratory, and colleagues analyze the temporal association between folic acid fortification and the rise in colorectal cancer rates, and present their resulting hypothesis in an article in the July issue of Cancer Epidemiology Biomarkers & Prevention. "Nationwide fortification of enriched grains is generally considered one of the greatest advances in public health policy," says Mason, who is also an associate professor at the Friedman School of Nutrition Science and Policy at Tufts. "But since the time that the food supply in North America was fortified with folic acid, we have been experiencing four to six additional cases of colorectal cancer for every 100,000 individuals each year compared to the trends that existed before fortification.
"Our analysis suggests that this increase is not explained by chance or by increased cancer screening. Therefore, it is important to analyze risks and benefits of fortification, and encourage scientific debate in countries that are considering instituting or enhancing folic acid fortification." Mason and colleagues analyzed data from national cancer registries, one in the United States and another in Canada. The US data were derived from the nationwide Surveillance Epidemiology and End Results (SEER) registry that publishes cancer occurrence rates and survival data, covering approximately 26 percent of the population. The Canadian data were obtained from Canadian Cancer Statistics, an annual publication by the Canadian Cancer Society and the National Cancer Institute of Canada. In 1996 and 1998, there were abrupt reversals in the 15-year downward trends in colorectal cancer rates in the United States and Canada, respectively. Since peaking in 1998 in the United States and in 2000 in Canada, the rates have not returned to their earlier levels. Although folic acid fortification of enriched grains - including bread, cereal, flour, rice, and pasta - did not become mandatory until 1998, large food companies began voluntary fortification in 1996, first in the United States and later in Canada. Folic acid is the synthetic form of folate, a B vitamin that is essential for cell growth. After intestinal absorption, folic acid is converted to methyltetrahydrofolate, found naturally in foods such as leafy green vegetables, legumes and citrus fruits. "The body's response to folic acid appears to be complex," says Mason. "While fortification of the food supply is clearly beneficial for women of child-bearing age and their offspring, it is possible that it may, coincidentally, be linked to the increase in colorectal cancer rates. Our report is intended to create a foundation upon which to further explore that possibility." As Mason and colleagues note, there is a compelling body of scientific evidence suggesting that habitually high intakes of dietary folate are protective against colorectal cancer. Mason explains, however, that "There are several reasons why we may have inadvertently created the opposite effect with folic acid fortification. First, folate's pivotal role in DNA synthesis also makes it a potential growth factor for cancerous or pre-cancerous cells, and when administered in large quantities to individuals who unknowingly harbor cancer cells, it could paradoxically enhance cancer development. The addition of substantial quantities of folic acid into the foodstream may have facilitated the transformation of benign growths into cancers, or small cancers into larger ones," he says. "Second, the fact that a synthetic form of folate is used for fortification may be important," suggests Mason. "As the total amount of folic acid ingested increases, the mechanism that converts folic acid to methyltetrahydrofolate can become saturated. The leftover folic acid in the circulation might have detrimental effects, as it is not a natural form of the vitamin." At a time when many countries are debating whether or not to institute or enhance folic acid fortification, Mason and colleagues urge caution and debate. "We must examine the effects of folic acid fortification on the population as a whole, which includes better defining the nature of the relationship between folic acid fortification and colorectal cancer," says Mason. "Improved monitoring and further research in this field is important to our understanding of the long-term public health effects of fortification." Tufts University, Health Sciences Science News and Science Current Events Tag Cloud This tag cloud is a visual representation of term frequencies of random science news topics with common terms grouped together and emphasized by their display size. Cosmic Dust Psoriasis Blood Pressure Smoking cessation Eye Disease SARS Radiation Treatment Adiponectin Fructose Sudden Infant Death Syndrome Extrasolar Planet Nanospheres Melanin Stroke Sea Urchin Gallstones Visual Cortex Antimatter Imaging technique Binge Drinking Carbon Monoxide Lithium Television HIV transmission Cancer Survivor
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Related Folic Acid Current Events and Folic Acid News Articles UCF researcher's nanoparticles could someday lead to end of chemotherapy Nanoparticles specially engineered by University of Central Florida Assistant Professor J. Manuel Perez and his colleagues could someday target and destroy tumors, sparing patients from toxic, whole-body chemotherapies. Some neural tube defects in mice linked to enzyme deficiency Women of childbearing age can reduce the risk of having a child born with a neural tube defect such as spina bifida by eating enough folate or folic acid. However, folate prevents only about 70 percent of these defects. Folic acid to prevent congenital heart defects The Canadian policy of fortifying grain products with folic acid has already proved to be effective in preventing neural tube defects. Taking folic acid for a year before pregnancy may reduce risk of preterm birth Women who take folic acid supplements for at least one year before they become pregnant may cut their risk of having a premature baby by half, according to research published this week in the online journal, PLoS Medicine. Hopkins Children's study: Folic acid may help treat allergies, asthma Folic acid, or vitamin B9, essential for red blood cell health and long known to reduce the risk of spinal birth defects, may also suppress allergic reactions and lessen the severity of allergy and asthma symptoms. Immigrant women may be at higher risk of having a baby with a birth defect Immigrant women are less likely to use folic acid supplements before pregnancy to prevent spina bifida, particularly those who recently immigrated to the country, according to a new study led by a St. Michael's Hospital physician in collaboration with Statistics Canada, Health Canada and the University of Toronto. Pregnant women who smoke, urged to give up before 15-week 'deadline' Women who stop smoking before week 15 of pregnancy cut their risk of spontaneous premature birth and having small babies to the same as non-smokers, according to research published on bmj.com today. Low levels of vitamin B12 may increase risk for neural tube defects Children born to women who have low blood levels of vitamin B12 shortly before and after conception may have an increased risk of a neural tube defect, according to an analysis by researchers at the National Institutes of Health, Trinity College Dublin, and the Health Research Board of Ireland. Scientists discover why teeth form in a single row A system of opposing genetic forces determines why mammals develop a single row of teeth, while sharks sport several, according to a study published today in the journal Science. When completely understood, the genetic program described in the study may help guide efforts to re-grow missing teeth and prevent cleft palate, one of the most common birth defects. Children with inflammatory bowel disease have surprisingly high folate levels, study finds Children with newly diagnosed cases of inflammatory bowel disease have higher concentrations of folate in their blood than individuals without IBD, according to a new study led by researchers at the University of California, San Francisco and UC Berkeley. More Folic Acid Current Events and Folic Acid News Articles |
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