Could preventing colon cancer be as simple as developing a taste for yerba mate tea? In a recent University of Illinois study, scientists showed that human colon cancer cells die when they are exposed to the approximate number of bioactive compounds present in one cup of this brew, which has long been consumed in South America for its medicinal properties.
“The caffeine derivatives in mate tea not only induced death in human colon cancer cells, they also reduced important markers of inflammation,” said Elvira de Mejia, a U of I associate professor of food chemistry and food toxicology.
That’s important because inflammation can trigger the steps of cancer progression, she said.
In the in vitro study, de Mejia and former graduate student Sirima Puangpraphant isolated, purified, and then treated human colon cancer cells with caffeoylquinic acid (CQA) derivatives from mate tea. As the scientists increased the CQA concentration, cancer cells died as a result of apoptosis.
“Put simply, the cancer cell self-destructs because its DNA has been damaged,” she said.
The ability to induce apoptosis, or cell death, is a promising tactic for therapeutic interventions in all types of cancer, she said.
de Mejia said they were able to identify the mechanism that led to cell death. Certain CQA derivatives dramatically decreased several markers of inflammation, including NF-kappa-B, which regulates many genes that affect the process through the production of important enzymes. Ultimately cancer cells died with the induction of two specific enzymes, caspase-3 and caspase-8, de Mejia said.
Get screened for colon cancer
People with an average risk of colon cancer can consider screening beginning at age 50. But people with an increased risk, such as those with a family history of colon cancer, should consider screening sooner. African-Americans and American Indians may begin colon cancer screening at age 45.
Several screening options exist - each with its own benefits and drawbacks. Talk about your options with your doctor, and together you can decide which tests are appropriate for you. Options may include:
Annual fecal occult blood testing
Flexible sigmoidoscopy every five years
Colonoscopy every 10 years
Virtual colonoscopy (CT colonography) every five years
Stool DNA testing - though this is a new screening approach and it’s not clear how often it should be repeated
More frequent or earlier screening may be recommended if you’re at increased risk of colon cancer. Discuss the benefits and risks of each screening option with your doctor. You may decide one or more tests are appropriate for you.
“If we can reduce the activity of NF-kappa-B, the important marker that links inflammation and cancer, we’ll be better able to control the transformation of normal cells to cancer cells,” she added.
The results of the study strongly suggest that the caffeine derivatives in mate tea have potential as anti-cancer agents and could also be helpful in other diseases associated with inflammation, she said.
But, because the colon and its microflora play a major role in the absorption and metabolism of caffeine-related compounds, the anti-inflammatory and anti-cancer effects of mate tea may be most useful in the colon.
Colon cancer prevention for people with a high risk
Some treatments, including medications and surgery, have been found to reduce the risk of precancerous polyps or colon cancer. However, not enough evidence exists to recommend these medications to people who have an average risk of colon cancer. If you have an increased risk of colon cancer, discuss the benefits and risks of these preventive treatments with your doctor:
Aspirin. Some evidence links a reduced risk of polyps and colon cancer to regular aspirin use. However, studies of low-dose aspirin or short-term use of aspirin haven’t found this to be true. It’s likely that you may be able to reduce your risk of colon cancer by taking large doses of aspirin over a long period of time. But using aspirin in this way carries a risk of side effects, such as gastrointestinal bleeding and ulcers.
Other pain relievers. Other pain relievers, such as ibuprofen (Advil, Motrin, others) and naproxen (Aleve, others), have also been studied as a way to prevent colon cancer. Some studies have found these other pain relievers may reduce the risk of precancerous polyps and colon cancer. But side effects include ulcers and gastrointestinal bleeding. Some of these other pain relievers have been linked to an increased risk of heart problems.
Celecoxib (Celebrex). Celecoxib and other drugs known as COX-2 inhibitors provide pain relief. Some evidence suggests COX-2 drugs can reduce the risk of precancerous polyps in people who’ve been diagnosed with these polyps in the past. But COX-2 drugs carry a risk of heart problems, including heart attack. Two COX-2 inhibitor drugs were removed from the market because of these risks.
Surgery to prevent cancer. In cases of rare, inherited syndromes such as familial adenomatous polyposis, or inflammatory bowel disease such as ulcerative colitis, your doctor may recommend removal of your entire colon and rectum in order to prevent cancer from occurring.
“We believe there’s ample evidence to support drinking mate tea for its bioactive benefits, especially if you have reason to be concerned about colon cancer. Mate tea bags are available in health food stores and are increasingly available in large supermarkets,” she added.
The scientists have already completed and will soon publish the results of a study that compares the development of colon cancer in rats that drank mate tea as their only source of water with a control group that drank only water.
This in vitro study was published in Molecular Nutrition & Food Research, vol. 55, pp. 1509-1522, in 2011. Co-authors include Sirima Puangpraphant, now an assistant professor at Kasetsart University in Thailand; Greg Potts, an undergraduate student of the U of I; and Mark A. Berhow and Karl Vermillion of the USDA, ARS, National Center for Agricultural Utilization Research in Peoria, Illinois. The work was funded by the U of I Research Board and Puangpraphant’s Royal Thai Government Scholarship.
University of Illinois College of Agricultural, Consumer and Environmental Sciences