Featured Research

from universities, journals, and other organizations

Antioxidant Supplements May Lessen Benefit Of Radiation And Chemotherapy

Date:
May 28, 2008
Source:
Journal of the National Cancer Institute
Summary:
Cancer patients should avoid the routine use of antioxidant supplements during radiation and chemotherapy because the supplements may reduce the anticancer benefits of therapy, researchers have concluded.

Cancer patients should avoid the routine use of antioxidant supplements during radiation and chemotherapy because the supplements may reduce the anticancer benefits of therapy, researchers concluded in a commentary published online in the Journal of the National Cancer Institute.

Radiation and many chemotherapy agents work to kill cells by inducing free radicals that damage DNA and proteins. Therefore, there is a possibility that taking antioxidant supplements, such as vitamin E or β-carotene may interfere with the therapies and reduce their anticancer activity. On the other hand, some investigators hypothesize that antioxidant supplementation may protect healthy tissues and reduce the side effects of treatment. Despite two decades of research into this question, no clear answer has appeared.

To evaluate the potential harms or benefits of antioxidant supplementation, Brian D. Lawenda, M.D., of the Naval Medical Center San Diego and colleagues reviewed all of the randomized trials they could identify that tested the effect of antioxidant supplements on radiation therapy or chemotherapy.

In the case of radiotherapy, they identified nine studies that addressed the question, including two meta-analyses. However, only three studies were randomized controlled trials designed to look at the clinical effect of antioxidant therapy on radiation. In the largest of the randomized trials, antioxidant supplementation was associated with a reduction in overall survival. One antioxidant agent, amifostine, which is already approved by the U.S. Food and Drug Administration to increase radioresistance in healthy salivary gland tissues, may protect normal tissues without increasing tumor radioresistance. Lawenda and colleagues caution that the question needs to be studied further before a solid conclusion can be made.

The authors identified 16 randomized controlled trials that examined the impact of antioxidant supplementation on chemotherapy. Six of the trials were placebo-controlled.

Of the studies that included information on response rates, none reported a decrease in response in the antioxidant arm of the trial compared with the control arm. However, Lawenda and colleagues caution that none of the trials was large enough to reliably detect such differences.

"Despite some intriguing studies that have suggested the benefit of adjunctive antioxidant treatments in cancer patients, the totality of the available evidence is equivocal at best and leaves us with serious concerns about the potential for harm," the authors write.


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 Reference:

  1. Lawenda BD, Kelly KM, Ladas EJ, Sagar SM, Vickers A, Blumberg JB. Should Supplemental Antioxidant Administration Be Avoided During Chemotherapy and Radiation Therapy? J Natl Cancer Inst, 2008; 100:773-783 DOI: 10.1093/jnci/djn148

Cite This Page:

Journal of the National Cancer Institute. "Antioxidant Supplements May Lessen Benefit Of Radiation And Chemotherapy." ScienceDaily. ScienceDaily, 28 May 2008. <www.sciencedaily.com/releases/2008/05/080527193200.htm>.
Journal of the National Cancer Institute. (2008, May 28). Antioxidant Supplements May Lessen Benefit Of Radiation And Chemotherapy. ScienceDaily. Retrieved September 22, 2014 from www.sciencedaily.com/releases/2008/05/080527193200.htm
Journal of the National Cancer Institute. "Antioxidant Supplements May Lessen Benefit Of Radiation And Chemotherapy." ScienceDaily. www.sciencedaily.com/releases/2008/05/080527193200.htm (accessed September 22, 2014).

Share This



More Health & Medicine News

Monday, September 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Sierra Leone in Lockdown to Control Ebola

Sierra Leone in Lockdown to Control Ebola

AP (Sep. 21, 2014) Sierra Leone residents remained in lockdown on Saturday as part of a massive effort to confine millions of people to their homes in a bid to stem the biggest Ebola outbreak in history. (Sept. 20) Video provided by AP
Powered by NewsLook.com
Sierra Leone's Nationwide Ebola Curfew Underway

Sierra Leone's Nationwide Ebola Curfew Underway

Newsy (Sep. 20, 2014) Sierra Leone is locked down as aid workers and volunteers look for new cases of Ebola. Video provided by Newsy
Powered by NewsLook.com
Changes Found In Brain After One Dose Of Antidepressants

Changes Found In Brain After One Dose Of Antidepressants

Newsy (Sep. 19, 2014) A study suggest antidepressants can kick in much sooner than previously thought. Video provided by Newsy
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. 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