NEW YORK (Reuters Health) - In patients with colorectal adenomas, supplementation with physiological doses of folic acid reverses genomic DNA hypomethylation, suggesting a possible role for folic acid supplementation in colorectal cancer prevention, investigators report.
“Low folate status may increase the risk of neoplasia by inducing DNA hypomethylation, which can affect DNA stability and gene expression,” Dr. Maria Pufulete from King’s College London and associates note in the May issue of the journal Gut.
They tested the theory that folic acid supplementation (400 micrograms per day) increases DNA methylation in leucocytes and colorectal tissue in 31 patients with histologically confirmed colorectal adenoma in a randomized, double blind, placebo controlled study. They assessed global genomic DNA methylation and folate status before and after 10 weeks of supplementation with folic acid or placebo.
Following folic acid supplementation, serum and erythrocyte folate levels rose by 81% and 57% respectively, and plasma homocysteine levels fell by 12%. Moreover, folic acid supplementation led to increases in DNA methylation of 31% in leucocytes and 25% in colonic mucosa, confirming their hypothesis.
“Although the statistical effect was marginal, the present study is the first to report an increase in DNA methylation in subjects with adenoma using a physiological dose of folate for a relatively short intervention period,” Dr. Pufulete and colleagues note.
The study findings, they add, support the view that “suboptimal intakes of folate may lead to hypomethylation, which in turn could be involved in the aetiology of colorectal cancer.”
In a commentary, Dr. John C. Mathers from the University of Newcastle, Newcastle upon Tyne, UK, says it will be important to build on these novel observations to determine “optimal intakes of folate to minimize the risk of bowel cancer.”
Source: Gut 2005;54:579-580,648-653. [ Google search on this article ]
MeSH Headings:Alkylation: Behavioral Sciences: Biological Sciences: Biology: Chemistry: Chemistry, Organic: Community Psychiatry: Behavioral Disciplines and Activities: Environment and Public Health: Genetics: Genetics, Biochemical: Health Occupations: Medicine: Methylation: Molecular Biology: Physical Sciences: Preventive Medicine: Preventive Psychiatry: Primary Prevention: Psychiatry: Specialties, Medical: DNA Methylation: Biological Sciences: Physical Sciences: Psychiatry and PsychologyCopyright © 2002 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.
