Featured Research

from universities, journals, and other organizations

Vitamins C And E And Beta Carotene Again Fail To Reduce Cancer Risk In Randomized Controlled Trial

Date:
January 4, 2009
Source:
Journal of the National Cancer Institute
Summary:
Women who took beta carotene or vitamin C or E or a combination of the supplements had a similar risk of cancer as women who did not take the supplements, according to data from a randomized controlled trial.

Women who took beta carotene or vitamin C or E or a combination of the supplements had a similar risk of cancer as women who did not take the supplements, according to data from a randomized controlled trial.

Epidemiological studies have suggested that people whose diets are high in fruits and vegetables, and thus antioxidants, may have a lower risk of cancer. Results from randomized trials that address the issue, however, have been inconsistent and have rarely supported that observation.

In the current study, Jennifer Lin, Ph.D., of the Brigham and Women's Hospital and Harvard Medical School in Boston, and colleagues tested the impact of antioxidant supplements on cancer incidence in a randomized controlled trial. A total of 7,627 women who were at high risk of cardiovascular disease were randomly assigned to take vitamin C, vitamin E, or beta-carotene.

With an average of 9.4 years of follow-up time, there was no statistically significant benefit from antioxidant use compared with placebo in terms of disease risk or mortality due to cancer. Overall, 624 women developed cancer and 176 died from cancer during the follow-up time. Compared with placebo, the relative risk of a new cancer diagnosis was 1.11 for women who took vitamin C, 0.93 for women who took vitamin E, and 1.00 for women who took beta carotene. None of these relative risks was statistically significantly different from 1.

"Supplementation with vitamin C, vitamin E, or beta carotene offers no overall benefits in the primary prevention of total cancer incidence or cancer mortality," the authors conclude. "In our trial, neither duration of treatment nor combination of the three antioxidant supplements had effects on overall fatal or nonfatal cancer events. Thus, our results are in agreement with a recent review of randomized trials indicating that total mortality was not affected by duration of supplementation and single or combined antioxidant regimens."

In an accompanying editorial, Demetrius Albanes, M.D., of the National Cancer Institute, reviewed data from previous randomized controlled trials that examined supplement use and cancer incidence. He noted that while the trial data reported by Lin are negative with respect to lowering cancer risk, there is valuable information uncovered that should not be overlooked. There was a trend for a reduction in colon cancer with vitamin E supplementation, which has been observed in other studies. Additionally, beta carotene use was associated with a modest excess of lung cancer, which is consistent with previous reports.

"Null trials or those with unexpected outcomes should not, however, be viewed as failures; they have and will con¬tinue to shed light on the causes of cancer and help us discover the means for its prevention," the editorialist concludes.


Story Source:

The above story is based on materials provided by Journal of the National Cancer Institute. Note: Materials may be edited for content and length.


Journal References:

  1. Lin J et al. Vitamins C and E and Beta Carotene Supplementation and Cancer Risk: A Randomized Controlled Trial. J Natl Cancer Inst, 2009:101:14-23
  2. Albanes D. Vitamin Supplements and Cancer Prevention: Where Do Randomized Controlled Trials Stand? J Natl Cancer Inst, 2009:101:2-4

Cite This Page:

Journal of the National Cancer Institute. "Vitamins C And E And Beta Carotene Again Fail To Reduce Cancer Risk In Randomized Controlled Trial." ScienceDaily. ScienceDaily, 4 January 2009. <www.sciencedaily.com/releases/2008/12/081231005315.htm>.
Journal of the National Cancer Institute. (2009, January 4). Vitamins C And E And Beta Carotene Again Fail To Reduce Cancer Risk In Randomized Controlled Trial. ScienceDaily. Retrieved September 16, 2014 from www.sciencedaily.com/releases/2008/12/081231005315.htm
Journal of the National Cancer Institute. "Vitamins C And E And Beta Carotene Again Fail To Reduce Cancer Risk In Randomized Controlled Trial." ScienceDaily. www.sciencedaily.com/releases/2008/12/081231005315.htm (accessed September 16, 2014).

Share This



More Health & Medicine News

Tuesday, September 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

President To Send 3,000 Military Personnel To Fight Ebola

President To Send 3,000 Military Personnel To Fight Ebola

Newsy (Sep. 16, 2014) — President Obama is expected to send 3,000 troops to West Africa as part of the effort to contain Ebola's spread. Video provided by Newsy
Powered by NewsLook.com
Man Floats for 31 Hours in Gulf Waters

Man Floats for 31 Hours in Gulf Waters

AP (Sep. 16, 2014) — A Texas man is lucky to be alive after he and three others floated for more than a day in the Gulf of Mexico when their boat sank during a fishing trip. (Sept. 16) Video provided by AP
Powered by NewsLook.com
EU Ministers and Experts Meet to Discuss Ebola Reponse

EU Ministers and Experts Meet to Discuss Ebola Reponse

AFP (Sep. 15, 2014) — The European Commission met on Monday to coordinate aid that the EU can offer to African countries affected by the Ebola outbreak. Duration: 00:58 Video provided by AFP
Powered by NewsLook.com
Despite The Risks, Antibiotics Still Overprescribed For Kids

Despite The Risks, Antibiotics Still Overprescribed For Kids

Newsy (Sep. 15, 2014) — A new study finds children are prescribed antibiotics twice as often as is necessary. Video provided by Newsy
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:
from the past week

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