In a study of people with precancerous lesions called leukoplakia, Italian researchers found the lesions disappeared in 28 percent of participants, and 44 percent experienced at least a partial shrinking of their lesions. All of the study participants took 5 milligrams of folic acid three times a day for six months.
While that would seem to be encouraging news, Dr. Jay Brooks, chairman of hematology/oncology at Ochsner Health System in Baton Rouge, La., said the finding may not lead to significant rewards.
"It's an early study. It appears to benefit a very small number of people, and in some people with leukoplakia, it naturally goes away anyway. I really can't tell you if it's good for you or bad for you," Brooks said.
The study authors said the new research is just an initial look at folic acid's possible cancer-preventing properties.
"The present work was aimed at a preliminary evaluation of folic acid as a novel chemopreventive agent. Definitive conclusions are far from being drawn because reliable data about spontaneous regression of leukoplakia are lacking," wrote the authors, from Universita Cattolica del Sacro Cuore, in Rome.
Results of the study appear in the July 15 issue of the journal Cancer.
Each year, nearly 40,000 Americans are diagnosed with head and neck cancers, including cancer of the larynx, according to the U.S. National Cancer Institute. These types of cancer are most common in people older than 50, and tobacco use is the number-one risk factor for these malignancies, according to the NCI. Unlike most other cancers, laryngeal cancer hasn't seen any improvement in five-year survival rates during the past 30 years, according to background information in the study.
For the study, the researchers recruited 43 people who had been diagnosed with laryngeal leukoplakia. Most -- 88 percent -- were smokers, and all but three were men.
Because prior studies had shown that people with head and neck cancers and laryngeal leukoplakia often have low blood levels of folate, the natural form of folic acid, the researchers wanted to learn if folic acid could help prevent the progression of leukoplakia to cancer.
So, each study participant was asked to take 5 milligrams of folic acid three times a day for six months.
Blood tests were done periodically to ensure the volunteers were taking their supplements as requested. The researchers also measured the leukoplakias once a month.
Twelve people -- 28 percent -- showed no response to the folic acid regimen. Nineteen people -- 44 percent -- experienced a partial shrinkage of their leukoplakia, and 12 people -- 28 percent -- had a "complete response," meaning their leukoplakia disappeared.
"Such results open intriguing perspectives, considering also the fact that hypofolatemia [low folate levels] has been reported in 2001 to be the most frequent vitamin deficiency in the U.S. population," wrote the authors, who are planning on conducting a larger, randomized, placebo-controlled trial to better assess folic acid's benefits.
In the meantime, Ochsner's Brooks said he wouldn't recommend folic acid supplements. "Few people are folic-acid deficient now that it's being added to breads and cereals. I think this study, once again, teaches us that we need to do large, randomized studies to see if things really work before we start taking them."
Samantha Heller, a senior clinical nutritionist at New York University Medical Center, said, "It's a very small study, and even the authors say that conclusions can't be drawn from this study."
"But, the bottom line is that folate is a very important B vitamin, and low levels may be involved in certain carcinogenic processes," she added. "I would like to see people getting folate from vegetables, fruits and legumes, rather than from a folic acid supplement. These foods have other cancer-fighting properties and can help protect against other chronic diseases."
Heller recommended daily consumption of 400 micrograms of folate or folic acid, preferably folate from food sources.