(NaturalNews) Founded in 1907, the American Association for Cancer Research (AACR) is the world's oldest and largest organization dedicated to advancing cancer research. So when its members (comprised of cancer researchers, oncologists and other health care professionals) meet for a national conference, research about the latest advancements in fighting cancer is announced and discussed. That's what happened at the recent AACR Frontiers in Cancer Prevention Research Conference, held in Houston. And three of the most hopeful new studies about preventing and treating prostate cancer all had something in common -- they involved totally natural therapies.
For starters, German scientists presented research showing that hops could play a role in preventing prostate cancer. Hops, the flowering clusters of the plant known to botanists as Humulus lupulus, are not only used as a flavoring agent in beer and other beverages, but they have long been used as a traditional herbal medicine. Previous studies have found that a specific phytochemical called xanthohumol in hops binds to estrogen receptors and may prevent breast cancer. Because testosterone receptors act similarly to estrogen receptors, scientists have theorized the natural hops compound might also bind to testosterone receptors and fight prostate cancer.
So, in order to study the impact of xanthohumol on prostate cancer, a research team headed by Clarissa Gerhauser, Ph.D., the group leader of cancer chemoprevention in the Division of Epigenomics and Cancer Risk Factors at the German Cancer Research Center in Heidelberg, worked with hormone-dependent prostate cancer cells in the lab. First they stimulated the cells with testosterone. This created a huge excess of prostate specific antigen (PSA), which is associated with prostate cancer in men.
But when prostate cancer cells were treated with testosterone and xanthohumol, the hops phyotchemical inhibited the secretion of PSA and blocked other hormone-dependent actions that spur cancer growth. In fact, molecular testing showed that xanthohumol directly binds to the male hormone receptor structure.
"We hope that one day we can demonstrate that xanthohumol prevents prostate cancer development, first in animal models and then in humans, but we are just at the beginning," Dr. Gerhauser said in a statement to the media.
Anti-cancer properties of coffee
Another natural substance also was in the spotlight at the Frontiers in Cancer Prevention Research Conference -- coffee. In the first study of its kind, Harvard scientists found a strong association between drinking coffee and a lowered risk of the most aggressive and deadly forms of prostate cancer.
"Coffee has effects on insulin and glucose metabolism as well as sex hormone levels, all of which play a role in prostate cancer. It was plausible that there may be an association between coffee and prostate cancer," Kathryn M. Wilson, Ph.D., a postdoctoral fellow at the Harvard Medical School and the Harvard School of Public Health, said in a press statement.
Dr. Wilson and her research team documented the regular and decaffeinated coffee intake of nearly 50,000 men every four years from 1986 to 2006; 4,975 of these men were diagnosed with prostate cancer over that period. The scientists found that men who drank the most coffee had a 60 percent lower risk of aggressive prostate cancer than men who were not coffee drinkers.
Caffeine is not the explanation for this association, Dr. Wilson emphasized. Instead, the researchers noted that coffee contains many biologically active natural compounds, including antioxidants and minerals, that could explain the lowered risk of the most serious forms of prostate cancer in coffee drinkers.
Exercise prevents prostate cancer
For men already diagnosed with prostate cancer, there was also hopeful news revealed at the AACR meeting. Researchers found that as little as 15 minutes of exercise daily reduced overall mortality rates in patients with prostate cancer.
"We saw benefits at very attainable levels of activity," said Stacey A. Kenfield, Sc.D., epidemiology research associate at the Harvard School of Public Health and lead author of the study, in a media statement. "The results suggest that men with prostate cancer should do some physical activity for their overall health."
The research team documented the physical activity levels of 2,686 prostate cancer patients without metastases who were enrolled in the Health Professionals Follow-up Study. Men who engaged in three or more hours of moderate to intense exercise (the equivalent of jogging, biking, swimming or playing tennis) for about a half an hour per week lowered their risk of overall mortality by 35 percent.
Men who walked four or more hours a week had a 23 percent lower risk of death from all causes compared to men who walked less than 20 minutes per week. And men who walked 90 or more minutes at a normal to brisk pace had a 51 percent lower risk of death from any cause than men who walked less than 90 minutes at a slower, easier pace. What's more, the research revealed that five or more hours of vigorous physical activity a week significantly reduced the risk of a man dying specifically from prostate cancer.
"This is the first large population study to examine exercise in relation to mortality in prostate cancer survivors," Dr. Kenfield said in a press statement. She added that while researchers haven't figured out the exact molecular effects exercise has on prostate cancer, they do know exercise has a favorable impact on hormones hypothesized to stimulate prostate cancer -- and exercise boosts immune function and reduces inflammation, too.
"How these factors may work together to affect prostate cancer biologically is still being studied," she concluded. "For now, our data indicate that for prostate cancer survivors, a moderate amount of regular exercise may improve overall survival, while five or more hours per week of vigorous exercise may decrease the death rate due to prostate cancer."