Green tea drinkers show lower cancer risks

NEW YORK (Reuters Health) - Older women who regularly drink green tea may have slightly lower risks of colon, stomach and throat cancers than women who make no time for tea, a large study suggests.

Researchers found that of more than 69,000 Chinese women followed for a decade, those who drank green tea at least three times a week were 14 percent less likely to develop a cancer of the digestive system.

That mainly meant lower odds of colon, stomach and esophageal cancers.
No one can say whether green tea, itself, is the reason. Green-tea lovers are often more health-conscious in general.

The study did try to account for that, said senior researcher Dr. Wei Zheng, who heads epidemiology at Vanderbilt University School of Medicine in Nashville.

None of the women smoked or drank alcohol regularly. And the researchers collected information on their diets, exercise habits, weight and medical history.

Even with those things factored in, women's tea habits remained linked to their cancer risks, Zheng noted.

Still, he said in an email, this type of study cannot prove cause-and-effect.

What's more, past studies have so far come to conflicting findings on whether green-tea drinkers really do have lower cancer risks. All of those studies are hampered by the fact that it's hard to isolate the effect of a single food in a person's diet on the risk of cancer.

Really, the only types of studies that can give strong evidence of cause-and-effect are clinical trials, wherein people would be randomly assigned to use green tea in some form, or not.

But few clinical trials have looked at whether green tea can cut cancer risk, and their results have been inconsistent, according to the National Cancer Institute.

There is "strong evidence" from lab research - in animals and in human cells - that green tea has the potential to fight cancer, Zheng's team writes in the American Journal of Clinical Nutrition.
Green tea contains certain antioxidant chemicals - particularly a compound known as EGCG - that may ward off the body-cell damage that can lead to cancer and other diseases.
For their study, Zheng and his colleagues used data from a long-running health study of over 69,000 middle-aged and older Chinese women. More than 19,000 were considered regular green-tea drinkers. (They had the beverage at least three times per week.)
Over 11 years, 1,255 women developed a cancer of the digestive system. In general, the risks were somewhat lower when a woman drank green tea often and for a long time.

For example, women who said they'd regularly had green tea for at least 20 years were 27 percent less likely than non-drinkers to develop any digestive system cancer. And they were 29 percent less likely to develop colorectal cancer, specifically.

None of that proves you should start drinking green tea to thwart cancer.

Women who downed a lot of green tea in this study were also younger, ate more fruits and vegetables, exercised more and had higher-income jobs. The researchers adjusted their data for all those differences - but, they write, it's not possible to perfectly account for everything.

If you want to start drinking green tea, it's considered safe in moderate amounts, says the National Center for Complementary and Alternative Medicine. But the tea and its extracts do contain caffeine, which some people may need to avoid.

Green tea also contains small amounts of vitamin K, which means it could interfere with drugs that prevent blood clotting, like warfarin. Since many older people are on multiple medications, it's wise for them to talk with their doctors before using green tea as a health tonic.

SOURCE: http://bit.ly/OZXHcT American Journal of Clinical Nutrition, November, 2012.

Acupuncture may ease dry mouth after cancer

NEW YORK (Reuters Health) - People with chronic dry mouth related to cancer treatment reported some improvement in symptoms like sticky saliva and dry lips after eight weeks of group acupuncture, in a new study from the UK.

It's not clear how much of that benefit could have been a result of patients' expectations that acupuncture would help them or the effect of a therapeutic relationship with their acupuncturist - rather than the actual needles - researchers said.

The study's lead author said more work is needed to answer those questions. But regardless, he thinks acupuncture should be offered to people with dry mouth related to radiation.

"These are patients for whom no other treatment has been helpful, and they feel better and their life has been improved as a result of this intervention," oncologist Dr. Richard Simcock, from the Sussex Cancer Centre in Brighton, told Reuters Health.

Dry mouth is a common side effect of radiation treatment for head and neck cancers, but the only prescription drug used to treat it - known as Salagen (pilocarpine) - comes with side effects. Other options, like special toothpastes and mouthwashes, don't always offer relief.

Acupuncturists have been convinced their therapy could help these patients for years. But there hasn't been much evidence for or against it, and head and neck cancer patients typically don't seek out alternative medicine, according to Simcock.

His team's study included 144 patients from seven UK cancer centers who had chronic dry mouth after radiation for head or neck cancer. They were all more than a year and a half out from radiation therapy.

The researchers sent participants to two hour-long educational sessions on oral care or eight weekly 20-minute sessions of group acupuncture targeting traditional points in the head and fingers believed to influence the salivary glands.

After the first round of treatment ended, patients switched assignments.

By the end of their acupuncture sessions, participants were between 1.65 and 2.08 times more likely to report improvements in five of six dry mouth symptoms, including having to wake up at night to drink water, than after they'd only learned about oral care.

Still, of patients with severe dry mouth at the start of the study, only about one-quarter reported an improvement.

WHAT'S BEHIND THE EFFECT?
The findings are partly limited by the study design, researchers said. In an ideal trial, participants wouldn't know if they were getting real acupuncture or a fake treatment without any expected benefit.

Because of the difficulty of finding a "control" group to compare to acupuncture treatment, it's hard to know how much of the benefit was really due to the effects of the needles themselves, rather than patient expectations.

Participants' saliva production was no different after acupuncture than after the oral care sessions, Simcock and his colleagues reported Wednesday in the Annals of Oncology.
The researcher said future studies should look into how long the effects of acupuncture last, as well as what may explain its benefit.
Some theories suggest acupuncture might directly stimulate the salivary glands, he said, or increase brain activity in ways that affect how patients perceive their dry mouth symptoms.
And even if the placebo effect is largely driving the results, it's not a reason to dismiss acupuncture, some researchers say.
"Even though we know a portion of acupuncture (benefit) is due to placebo, the patients reported improvements, and at the end of the day the objective... is to improve how people feel," Lorenzo Cohen, a cancer researcher from the University of Texas MD Anderson Cancer Center in Houston, who wasn't involved in the new study, told Reuters Health.

Simcock said because acupuncture was done in a group setting in the new study, each practitioner could treat up to seven patients in an hour. With compensation of about $50 to $60 per hour, that makes the treatment cost-effective when it's done in a place with high demand, he added.

"I think it is a treatment that can and should be offered within cancer centers," Simcock said.

Dr. Lawrence Berk, head of radiation oncology at the University of South Florida in Tampa, called the results "kind of a mixed picture."

"The advantage of something like this is that it's very non-invasive," Berk, who also didn't participate in the new research, told Reuters Health. "If you didn't get the benefit, there's no harm done outside of cost."

Cohen agreed that as long as it's delivered by a qualified practitioner, acupuncture is very safe.

Soreness can be a side effect, and rare complications of acupuncture include infections and organ damage.

SOURCE: http://bit.ly/wctYGR Annals of Oncology, online October 24, 2012.