Doctor: Think twice before taking folate

HOUSTON, Dec. 23 (UPI) -- A U.S. cancer doctor suggests rethinking the policy of everyone taking some extra folate because it could increase cancer risk.

Study co-author Dr. Jean-Pierre Issa of the M.D. Anderson Cancer Center in Houston says high levels of this B vitamin -- often added to grain products to prevent neural tube defects in newborns -- may play a role in a process known as DNA methlation. Methylated genes have been found in colon, breast, prostate and lung tumors.

The study, published in Cancer Prevention Research, linked high red blood cell levels of folate and the shutting down by DNA methylation of two tumor suppressing genes.

"Today it's worrisome that taking extra folate over the long term might lead to more DNA methylation, which then might lead to extra diseases including potentially an increased chance of developing cancer and other diseases of aging," Issa says in a statement." I personally think people taking folate should think twice about it."

Issa and colleagues looked at 781 patients from a clinical trial comparing folate to aspirin in the prevention of pre-cancerous colorectal polyps.

They examined methylation of two tumor-suppressing genes between two colonoscopies performed three years apart.