Skip to content
My WebMD Sign In, Sign Up

Colorectal Cancer Health Center

Font Size

Selenium May Lower Colon Cancer Risk

By
WebMD Health News

Nov. 16, 2004 -- Add colon cancer to the list of cancers that may be affected by selenium. High blood levels of the mineral were associated with lower colon cancer risk in a new study.

Selenium has drawn attention for its potential cancer-fighting abilities. Several studies show it combats prostate cancer, and it's also been studied for its affects on lung and bladder cancer.

Past research on selenium and colorectal cancer has yielded mixed results, with some experts reporting a drop in colon cancer risk with selenium and others finding no selenium advantage.

Those studies may have been too small to track the mineral's impact, say researchers including Elizabeth Jacobs, PhD, of the Arizona Cancer Center at the University of Arizona.

To fix that problem, Jacobs and colleagues analyzed data from more than 1,700 people who had participated in three earlier colorectal cancer trials.

Each trial focused on preventing colorectal adenomas -- cancerous outgrowths or polyps in the colon or rectum. Participants had already had one adenoma removed during colonoscopy and were trying different nutritional approaches to avoid a recurrence of the cancerous polyps.

One trial tested a high-fiber cereal supplement. Another used a low-fat, high-fiber diet with many fruits and vegetables. The third study involved vitamin C, E, and beta-carotene supplements. The main dietary sources of selenium in the U.S. are grains.

Taking all three trials into consideration, Jacobs and colleagues found that participants with the highest blood levels of selenium were 34% less likely to develop a new adenoma compared with those with the lowest selenium blood levels.

The results support previous findings that "higher selenium status may be related to decreased risk of colorectal cancer," write the researchers in the Nov. 17 issue of the Journal of the National Cancer Institute.

However, that's not necessarily a reason to stock up on selenium supplements.

None of the participants in the studies took selenium supplements, notes a Journal of the National Cancer Institute editorial by experts including Anna Duffield-Lillico of Memorial Sloan-Kettering Cancer Center in New York City.

A Little Selenium Goes a Long Way

People only need a tiny amount of selenium -- 55 micrograms per day for adults, according to the U.S. Recommended Daily Allowance.

It's easy to get that amount from a healthy diet. Meats, seafood, grains, and some nuts (such as Brazil nuts) are good sources of selenium. Foods grown in areas with selenium-rich soils have higher levels of the mineral, but selenium deficiency is rare in the U.S.

Expect more news in the future on selenium and colon cancer. More than 35,000 men are currently taking part in a cancer prevention trial that will include an assessment of selenium and colorectal cancer, note Duffield-Lillico and colleagues.

Today on WebMD

colorectal cancer slideshow
SLIDESHOW
what is your cancer risk
HEALTH CHECK
 
Colon Cancer Survival
VIDEO
Kemeny Chemo Side Effects
VIDEO
 

bread
ARTICLE
Colon vs Rectal Cancer
VIDEO
 
New Colorectal Treatments
VIDEO
can lack of sleep affect your immune system
FEATURE
 

Cancer Facts Quiz
QUIZ
Virtual Colonoscopy
VIDEO
 
Picture of the Colon
ANATOMY
Vitamin D
SLIDESHOW
 

WebMD Special Sections