A plant-based diet, low in dairy and meat but rich in fruits, vegetables, grains, and nuts, can improve sexual and urinary health in patients treated for local prostate cancer, new research showed.
The findings, published on February 13, 2024, in the journal Cancer, bolster previous research showing plant-based diets can reduce the risk for recurrence and improve survivorship in men with prostate cancer.
"The current study shows for the first time an association between eating more plant-based food with better scores for quality of life among patients diagnosed with prostate cancer," Stacy Loeb, MD, a urologist in the Departments of Urology and Population Health at NYU Langone Health, in New York City, who led the research.
For the new study, Loeb and her colleagues looked at data from more than 3500 men with prostate cancer in the Health Professionals Follow-Up Study, an ongoing investigation begun in 1986 and sponsored by Harvard T.H. Chan School of Public Health. The dataset included more than 50,000 male dentists, pharmacists, optometrists, osteopaths, podiatrists, and veterinarians.
The median age of prostate cancer diagnosis was 68 years; 48% of patients underwent radical prostatectomy and 35% had radiation as primary therapy. None of the patients were known to have had metastatic disease.
Men in the study answered a questionnaire every 4 years about the kinds of foods they ate and in what proportions. Another survey, administered every 2 years, assessed the frequency of incontinence, difficulties maintaining an erection, and problems with bowels, energy, and mood, among many other health concerns.
Loeb and her colleagues sorted patients into quintiles based on the proportion of plant vs animal foods the men said they eat. The authors found those who consumed the most plant-based foods scored 8%-11% better in measures of sexual function than the group that consumed the least of these products.
These men also reported up to 14% better scores for urinary health, with fewer instances of incontinence, obstruction, and irritation, and up to 13% better scores in hormonal health, marked by symptoms like low energy, depression, and hot flashes.
Justin Gregg, MD, a urology researcher at the University of Texas MD Anderson Cancer Center, in Houston, Texas, whose research has found the Mediterranean diet can slow tumor progression among men with localized prostate cancer on active surveillance, called the results "not entirely surprising, as prior studies have shown associations between plant-based diet and outcomes like erectile function among men who do not have prostate cancer."
But Kenneth Jacobsohn, MD, professor of urology and director of lifestyle medicine at the Medical College of Wisconsin, in Milwaukee, Wisconsin, said the new findings help establish "the positive role of diet quality and plant-based diets, specifically on quality of life after prostate cancer diagnosis and treatment for men with nonmetastatic prostate cancer."
Jacobsohn said the study was limited by its retrospective nature and the manner of the dietary assessment.
"As the authors point out, a plant-based diet may be helpful, though it's important to keep in mind the strong data for its protective effect in terms of cardiovascular disease risk, which is very important for men who have a history of prostate cancer as many will die of cardiovascular disease," Gregg added.
Loeb, Gregg, and Jacobsohn reported no conflicts of interest. Some of the study authors reported a variety of potential conflicts.
Howard Wolinsky is a journalist in Chicago.
