Strong-flavored onions show promise for fighting cancer

October 21, 2004

Strong-flavored onions can be harsh on your social life, but they're potentially great for fighting cancer. Researchers at Cornell University have found, in preliminary lab studies, that members of the onion family with the strongest flavor -- particularly New York Bold, Western Yellow and shallots -- are the best varieties for inhibiting the growth of liver and colon cancer cells. "No one knows yet how many daily servings of onions you'd have to eat to maximize protection against cancer, but our study suggests that people who are more health-conscious might want to go with the stronger onions rather than the mild ones," says study leader Rui Hai Liu, M.D., Ph.D., a chemist with Cornell's Department of Food Science in Ithaca, N.Y.

Researchers have known for some time that onions may help fight cancer, but the current study is believed to be the first to compare cancer-fighting abilities among commonly consumed onion varieties. The new study will appear in the Nov. 3 print issue of the Journal of Agricultural and Food Chemistry, a peer-reviewed journal of the American Chemical Society, the world's largest scientific society.

Liu and his associates analyzed 10 common onion varieties and shallots for total antioxidant activity and their ability to fight the growth of cancer in human cell lines. Although shallots resemble onions, they are actually a separate, distinctive species. Fresh, uncooked samples were used, with extracts taken from the bulbs with the outer skin removed.

Shallots and onion varieties with the strongest flavor -- Western Yellow, New York Bold and Northern Red -- had the highest total antioxidant activity, an indication that they may have a stronger ability to destroy charged molecules called free radicals, an excess of which are thought to increase the risk of disease, particularly cancer, the researcher says.

Onion varieties with the mildest flavor -- Empire Sweet, Western White, Peruvian Sweet, Mexico, Texas 1015, Imperial Valley Sweet and Vidalia -- had the lowest total antioxidant activity, Liu says.

In tests against liver and colon cancer cells, onions were significantly better at inhibiting the growth of colon cancer cells than liver cancer cells, an indication that they are potentially better at fighting colon cancer, the researcher says. The strongest cancer-fighters tested were the New York Bold variety, Western Yellow and shallots. The sweetest tasting onions, including the beloved Vidalia, showed relatively little cancer-fighting ability, he notes.

Green onions and cocktail onions were not tested in this study, nor did the researcher test whether cooking made a difference in terms of cancer-fighting ability. Liu cautions that human studies are needed before any definitive links between onion consumption and cancer-prevention can be established.

While popular as fried "rings," onions are known mostly for their ability to add flavor to a variety of food dishes, including meats, pizza, soups and salads. But they are increasingly becoming known for their potential health benefits. Onions are rich in a flavor compound known as quercetin, a potent antioxidant that has been linked to protection against cataracts and heart disease as well as cancer. They are also sodium, fat and cholesterol free.

Onions are the third-most consumed vegetable crop in the United States, with a per capita consumption estimated around 19 pounds per year and a retail value estimated at $3 billion to $4 billion, according to the National Onion Association.

Onions can be part of a healthy diet. The National Cancer Institute recommends eating at least five servings of fruits and vegetables a day.
-end-
The New York State Department of Agriculture and Markets provided funding for this study.

The American Chemical Society is a nonprofit organization, chartered by the U.S. Congress, with a multidisciplinary membership of more than 159,000 chemists and chemical engineers. It publishes numerous scientific journals and databases, convenes major research conferences and provides educational, science policy and career programs in chemistry. Its main offices are in Washington, D.C., and Columbus, Ohio.

-- Mark T. SampsonThe online version of the research paper cited above was initially published Oct. 7 on the journal's Web site. Journalists can arrange access to this site by sending an e-mail tonewsroom@acs.orgor calling the contact person for this release.

American Chemical Society

Related Cancer Articles from Brightsurf:

New blood cancer treatment works by selectively interfering with cancer cell signalling
University of Alberta scientists have identified the mechanism of action behind a new type of precision cancer drug for blood cancers that is set for human trials, according to research published in Nature Communications.

UCI researchers uncover cancer cell vulnerabilities; may lead to better cancer therapies
A new University of California, Irvine-led study reveals a protein responsible for genetic changes resulting in a variety of cancers, may also be the key to more effective, targeted cancer therapy.

Breast cancer treatment costs highest among young women with metastic cancer
In a fight for their lives, young women, age 18-44, spend double the amount of older women to survive metastatic breast cancer, according to a large statewide study by the University of North Carolina at Chapel Hill.

Cancer mortality continues steady decline, driven by progress against lung cancer
The cancer death rate declined by 29% from 1991 to 2017, including a 2.2% drop from 2016 to 2017, the largest single-year drop in cancer mortality ever reported.

Stress in cervical cancer patients associated with higher risk of cancer-specific mortality
Psychological stress was associated with a higher risk of cancer-specific mortality in women diagnosed with cervical cancer.

Cancer-sniffing dogs 97% accurate in identifying lung cancer, according to study in JAOA
The next step will be to further fractionate the samples based on chemical and physical properties, presenting them back to the dogs until the specific biomarkers for each cancer are identified.

Moffitt Cancer Center researchers identify one way T cell function may fail in cancer
Moffitt Cancer Center researchers have discovered a mechanism by which one type of immune cell, CD8+ T cells, can become dysfunctional, impeding its ability to seek and kill cancer cells.

More cancer survivors, fewer cancer specialists point to challenge in meeting care needs
An aging population, a growing number of cancer survivors, and a projected shortage of cancer care providers will result in a challenge in delivering the care for cancer survivors in the United States if systemic changes are not made.

New cancer vaccine platform a potential tool for efficacious targeted cancer therapy
Researchers at the University of Helsinki have discovered a solution in the form of a cancer vaccine platform for improving the efficacy of oncolytic viruses used in cancer treatment.

American Cancer Society outlines blueprint for cancer control in the 21st century
The American Cancer Society is outlining its vision for cancer control in the decades ahead in a series of articles that forms the basis of a national cancer control plan.

Read More: Cancer News and Cancer Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.