Featured Research

from universities, journals, and other organizations

Folic Acid Supplements Linked To Higher Risk Of Prostate Cancer, Study Shows

Date:
March 18, 2009
Source:
University of Southern California
Summary:
Men who took a daily folic acid supplement of 1 mg daily had more than twice the risk of prostate cancer compared with men who took a placebo.

A study led by researchers at the University of Southern California (USC) found that men who took a daily folic acid supplement of 1 mg daily had more than twice the risk of prostate cancer compared with men who took a placebo.

The finding came from a secondary analysis of the Aspirin/Folate Polyp Prevention Study (AFPP), a placebo-controlled randomized trial to determine the impact of aspirin and folic acid on colon polyps in men and women who were at high risk for the disease. The results appear in the March 10 online issue of the Journal of the National Cancer Institute.

Folic acid (folate) is a B vitamin found in many vegetables, beans, fruits and whole grains. While evidence of its ability to reduce neural tube defects in infants while taken by the mother before or during pregnancy has been well documented, its effects on other conditions are unclear.

"We know that adequate folate levels are important in the prevention of several cancer types, cardiovascular and neurological diseases," says lead author Jane Figueiredo, Ph.D., assistant professor of preventive medicine at the Keck School of Medicine of USC. "However, little has been known about its role in prostate cancer. Our objective was to investigate the relationship between folic acid supplements and dietary folate and risk of prostate cancer."

The AFPP study was conducted between 1994 and 2006 and found that aspirin reduced the risk of colon polyps while folic acid had a negative effect and increased the risk of advanced and multiple polyps. The first analysis did not address the impact of folic acid supplements on prostate cancer risk. Previous observational studies have been inconsistent. Some studies suggest that increased folate in the diet or in supplements might actually lower the risk of prostate cancer, and others have suggested no effect or even a potential harmful effect.

In the secondary analysis, researchers looked at prostate cancer incidence among 643 men who were randomly assigned to 1 mg daily folic acid supplements or placebo in the AFPP study and who enrolled in an extended follow-up study. The estimated prostate cancer risk was 9.7 percent at 10 years in men assigned to folate, compared with 3.3 percent in men assigned to placebo.

By contrast, dietary folate intake and plasma folate showed a trend toward reduced risk of prostate cancer, although the difference did not reach statistical significance. It remains unclear why dietary and circulating folate among non-multivitamin users may be inversely associated with risk, Figueiredo says.

"The synthetic form of folate, folic acid, found in supplements, is more bioavailable compared to folate from dietary sources and we know the amount of folate available is critical," she says. "Adequate levels of folate may be beneficial, but too much folate is unlikely to be beneficial."

Alternatively, these results may be due to chance, and replication by other studies is needed, she notes.

"These findings highlight the potentially complex role of folate in prostate cancer. The possibility of different effects from folic acid-containing supplements versus natural sources of folate definitely merits further investigation."

The study was supported by the National Cancer Institute and the National Institutes of Health.


Story Source:

The above story is based on materials provided by University of Southern California. Note: Materials may be edited for content and length.


Journal Reference:

  1. Jane C. Figueiredo, Maria V. Grau, Robert W. Haile, Robert S. Sandler, Robert W. Summers, Robert S. Bresalier, Carol A. Burke, Gail E. McKeown-Eyssen, John A. Baron. Folic Acid and Risk of Prostate Cancer: Results From a Randomized Clinical Trial. Journal of the National Cancer Institute, DOI: 10.1093/jnci/djp019

Cite This Page:

University of Southern California. "Folic Acid Supplements Linked To Higher Risk Of Prostate Cancer, Study Shows." ScienceDaily. ScienceDaily, 18 March 2009. <www.sciencedaily.com/releases/2009/03/090310161436.htm>.
University of Southern California. (2009, March 18). Folic Acid Supplements Linked To Higher Risk Of Prostate Cancer, Study Shows. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2009/03/090310161436.htm
University of Southern California. "Folic Acid Supplements Linked To Higher Risk Of Prostate Cancer, Study Shows." ScienceDaily. www.sciencedaily.com/releases/2009/03/090310161436.htm (accessed October 1, 2014).

Share This



More Health & Medicine News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Cases Keep Coming for Monrovia's Island Hospital

Ebola Cases Keep Coming for Monrovia's Island Hospital

AFP (Oct. 1, 2014) A look inside Monrovia's Island Hospital, a key treatment centre in the fight against Ebola in Liberia's capital city. Duration: 00:34 Video provided by AFP
Powered by NewsLook.com
Ebola Puts Stress on Liberian Health Workers

Ebola Puts Stress on Liberian Health Workers

AP (Oct. 1, 2014) The Ebola outbreak is putting stress on first responders in Liberia. Ambulance drivers say they are struggling with chronic shortages of safety equipment and patients who don't want to go to the hospital. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Doctors Reassure Public Ebola Patient Won't Cause Outbreak

Doctors Reassure Public Ebola Patient Won't Cause Outbreak

Newsy (Sep. 30, 2014) After the announcement that the first U.S. patient had been diagnosed with Ebola, doctors were quick to say a U.S. outbreak is highly unlikely. Video provided by Newsy
Powered by NewsLook.com
TX Hospital Confirms Patient Admitted With Ebola

TX Hospital Confirms Patient Admitted With Ebola

AP (Sep. 30, 2014) Medical officials from Texas Health Presbyterian Hospital confirm they are treating a patient with the Ebola virus, the first case found in the US. (Sept. 30 Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins