Field Notes

Coffee Daily May Improve Colon Cancer Survival

Regular consumption of caffeinated coffee may help prevent the return of colon cancer after treatment and improve the chances of a cure, according to a study from the Dana-Farber Cancer Institute that reported this association for the first time.

The patients, all of them treated with surgery and chemotherapy for stage III colon cancer, had the greatest benefit from consuming four or more cups of coffee per day (about 460 mg of caffeine), according to the study published in August in the Journal of Clinical Oncology. These patients were 42% less likely to have their cancer return than noncoffee drinkers, and were 33% less likely to die from cancer or any other cause.

Two to three cups of coffee daily had a more modest benefit, while little protection was associated with one cup or less, reported the researchers, led by Charles Fuchs, MD, MPH, director of the Gastrointestinal Cancer Center at Dana-Farber. First author is Brendan J. Guercio, MD, also of Dana-Farber.

The study included nearly 1,000 patients who filled out dietary pattern questionnaires early in the study, during chemotherapy, and again about a year later. This “prospective” design eliminated patients’ need to recall their coffee-drinking habits years later—a source of potential bias in many observational studies.

“We found that coffee drinkers had a lower risk of the cancer coming back and a significantly greater survival and chance of a cure,” Fuchs says. Most recurrences happen within five years of treatment and are uncommon after that, he noted. In patients with stage III disease, the cancer has been found in the lymph nodes near the original tumor but there are no signs of further metastasis. Fuchs says these patients have about a 35% chance of recurrence.
As encouraging as the results appear to be, Fuchs is hesitant to make recommendations to patients until the results are confirmed in other studies. “If you’re a coffee drinker and are being treated for colon cancer, don’t stop,” he says. “But if you’re not a coffee drinker and wondering whether to start, you should first discuss it with your physician.”

Fuchs says this is the first study of an association between caffeinated coffee and risk of colon cancer recurrence. It adds to a number of recent studies suggesting that coffee may have protective effects against the development of several kinds of cancer, including reduced risks of postmenopausal breast cancer, melanoma, liver cancer, and advanced prostate cancer.
Fuchs adds the research focused on coffee and other dietary factors because coffee drinking, in addition to possibly being protective against some cancers, had been shown to reduce the risk of type 2 diabetes. Risk factors for diabetes—obesity, a sedentary lifestyle, a diet high in calories and sugar, and high levels of insulin—are also implicated in colon cancer.

In analyzing the results, Fuchs and colleagues discovered that the lowered risk of cancer recurrence and deaths was entirely due to caffeine and not other components of coffee. He says it’s unclear why caffeine has this effect and the question needs further study. One hypothesis is that caffeine consumption increases the body’s sensitivity to insulin so less of it is needed, which in turn may help reduce inflammation, a risk factor for both diabetes and cancer, Fuchs says.

Other than drinking coffee, Fuchs adds, people can take other measures to reduce cancer risks, such as avoiding obesity, exercising regularly, adopting a healthful diet, and eating nuts, which also reduce the risk of diabetes.

— Source: Dana-Farber Cancer Institute


Hot Chilies May Increase ‘Feeling of Fullness’

University of Adelaide researchers have discovered a high-fat diet may impair important receptors located in the stomach that signal fullness.

Published August 18, 2015, in the journal PLOS ONE, researchers from the University’s Centre for Nutrition and Gastrointestinal Diseases (based at the South Australian Health and Medical Research Institute) conducted laboratory studies to investigate the association between hot chili pepper receptors (TRPV1) in the stomach and the feeling of fullness.

“The stomach stretches when it’s full, which activates nerves in the stomach to tell the body that it’s had enough food. We found that this activation is regulated through hot chili pepper or TRPV1 receptors,” says Associate Professor Amanda Page, a senior research fellow in the University of Adelaide’s School of Medicine and lead author of the study.

“It’s known from previous studies that capsaicin, found in hot chilies, reduces food intake in humans. And what we’ve discovered is that deletion of TRPV1 receptors dampens the response of gastric nerves to stretch—resulting in a delayed feeling of fullness and the consumption of more food. Therefore, part of the effect of capsaicin on food intake may be mediated via the stomach.”

Page adds, “We also found that TRPV1 receptors can be disrupted in high-fat diet-induced obesity.”

Stephen Kentish, MD, says these findings will inform further studies and the development of new therapies. “It’s exciting that we now know more about the TRPV1 receptor pathway and that the consumption of capsaicin may be able to prevent overeating through an action on nerves in the stomach,” says Kentish, a National Health and Medical Research Council fellow from the University of Adelaide’s School of Medicine.

“The next stage of research will involve investigation of the mechanisms behind TRPV1 receptor activation with the aim of developing a more palatable therapy,” he says. “We’ll also do further work to determine why a high-fat diet desensitizes TRPV1 receptors and investigate if we can reverse the damage.”

— Source: University of Adelaide