SAN FRANCISCO – Healthy dietary and lifestyle factors can add up substantially to reduce the risk of prostate cancer death among men who are treated for the disease, suggests a study reported at the Genitourinary Cancers Symposium.
A team led by Stacey A. Kenfield, Sc.D., analyzed data for 3,583 men participating in the Health Professionals Follow-Up Study who received a diagnosis of nonmetastatic prostate cancer between 1986 and 2008. They assessed whether the men had 11 protective dietary and lifestyle factors after diagnosis and associations with prostate cancer–specific mortality.
Susan London/Frontline Medical News
Dr. Stacey A. Kenfield
Results showed that men having 8 to 11 of the protective factors were 75% less likely to die from the disease than were those having 0 to 3 of them. But full adoption wasn’t necessary to see benefit: Risk fell by 29% with each additional factor.
“Exercising vigorously regularly, not smoking, having a health body weight and a diet high in cruciferous vegetables and healthy sources of fat, having moderate amounts of coffee and wine, and avoiding processed meat, poultry with skin, whole milk, and excess supplemental selenium seem to be good for reducing one’s risk of lethal prostate cancer,” said Dr. Kenfield of the University of California, San Francisco.
“I would say, try to adopt as many as you can, but understandably, it’s hard to do all 11, as there was no one in this study who did at diagnosis,” she added.
Dr. Kenfield and her colleagues, along with the Prostate Cancer Foundation, have developed a booklet available online for patients and caregivers that covers many of the factors highlighted by the study.
In the Health Professionals Follow-Up Study, data were collected on smoking, weight, and physical activity every 2 years, and on diet every 4 years.
Drawing on the literature, the investigators assessed 11 protective factors: body mass index of less than 30 kg/m2, getting at least 3 hours of vigorous physical activity per week (or brisk walking for at least 7 hours per week), not currently smoking (or having quit at least a decade ago), consuming fewer than two servings per week of processed red meat, not consuming any poultry with skin, consuming at least one serving per day of cruciferous vegetables, getting less than 140 micrograms/day of selenium in supplements, consuming at least three servings per week of nuts or oil-based salad dressing, drinking fewer than four servings per week of whole milk, drinking at least four servings per day of coffee, and drinking at least seven servings of wine per week.
The investigators updated men’s status regarding these factors at the above intervals, but excluded data near the end of life to avoid bias introduced by adoption of healthy behaviors in response to facing terminal illness, Dr. Kenfield explained at the symposium, which was sponsored by the American Society of Clinical Oncology, ASTRO, and the Society of Urologic Oncology.
The prevalence of the various protective factors at diagnosis ranged widely, from 8% of men drinking at least seven servings of wine per week to 97% of men consuming fewer than four servings per week of whole milk, according to data reported in a poster session. The majority of men, 61%, had five or six of the protective factors.
During a median follow-up of 11 years, nearly 7% of the men died from prostate cancer. In multivariate analyses in which men having 0-3 of the protective factors were the reference group, those having 4-7 factors had a 48% lower risk of death from prostate cancer (hazard ratio, 0.52) and those having 8-11 factors had a 75% lower risk (HR, 0.25). Furthermore, risk fell with each additional protective factor (HR, 0.71).
Findings were similar when the investigators assessed only the food factors, only the drink factors, and only the lifestyle factors separately.
“There are not a lot of studies that have looked at these factors in association with prostate cancer death,” noted Dr. Kenfield. In fact, only a few U.S. cohorts have collected sufficient data after diagnosis to perform this type of analysis.
“We are hoping that there will be more data in the future, especially from Europe. They have a lot of different cohorts that have smoking, exercise, and diet data,” she concluded.