A report showed that prostate cancer patients with vegetarian dietary habits show more than half lower risks of progression and recurrence than meat-eating patients.
The American Society of Clinical Oncology (ASCO) noted the result of the study, “Associations between plant-based diets and risk of disease progression in men with prostate cancer,” which will be released at its Genitourinary Cancers Symposium in 2023, ASCO GU 2023, from Feb. 16-18.
The University of California research team, led by Vivian Liu, conducted the study based on the fact that little is known about the connection between a vegetarian diet and prostate cancer survival, although some foods, including tomato, lower the prevalence and mortality of prostate cancer.
They analyzed the association between plant-based diets and the disease progression in men with prostate cancer based on the food frequency questionnaire (FFQ) conducted on 2,038 men registered on CaPSURE, the national registry of the U.S. prostate cancer.
The subjects were diagnosed with early- to mid-degree (T1-T3a) prostate cancer and completed an FFQ on how much and how frequently they took from among 140 foods and beverages.
They also asked questions on other factors that could bias the evaluation, including smoking, walking speed, diabetes record, family history, income level, educational background, body mass index, alcohol intake, multivitamin intake, calcium supplement use, and selenium supplement use.
“These variables did not affect the results of an analysis of plant-based diets related to prostate cancer progression risk,” researchers said. “We evaluated walking speed because it, along with clinical factors such as age, cancer stage, and grade, was an important predictor of cancer progression in the previous study of this group.”
As a result of the analysis, they observed 204 progression events, 10 percent of the total 2,038 subjects, over a median follow-up of 7.4 years.
Participants who reported the largest amount of vegetarian diets showed 52 percent lower progression risk than those reporting the least plant-based diets. The former group’s recurrence risk was also 53 percent lower than the latter. This trend was consistent regardless of the participant's age, walking speed, diagnostic rating, or stage of cancer at the time of diagnosis.
“We hope this result will guide people at risk to choosing a better and healthier diet,” said Vivian N. Liu, the senior coordinator for clinical trials at Osher Center. “We already know that a diet that includes vegetables, fruits, beans, and whole grains has much to do with numerous health benefits, including diabetes, cardiovascular disease, and reduced overall mortality. We can add the benefits of reducing prostate cancer progression to the list."
Dr. Bradley Alexander McGregor, a special member of ASCO GU, said. “The risk of disease progression is one of the important concerns for prostate cancer patients and their families, caregivers, and doctors. These results allow us to provide direct information on clinical care, including dietary recommendations.”