Prostate cancer is bad enough, among the most common and deadly cancers affecting American men, according to the U.S. Centers for Disease Control and Prevention. But what's really unfortunate is that the life-saving treatment for prostate cancer can make the patient's quality-of-life worse.

Surgery to remove the cancerous prostate, radiation and other common on-going therapies which affect the patient's hormonal balance too often cause erectile dysfunction and urinary incontinence, irritation and obstruction. Physicians have tried to minimize these unwanted side effects of treatment, but these issues of concern remain.

“Adding more fruits and vegetables to their diet, while reducing meat and dairy, is a simple step that patients can take.”

Now, a new study suggests that what you eat may help minimize these side effects for men who have undergone prostate removal or hormonal suppression.

According to researchers from NYU Grossman School of Medicine and Harvard T.H. Chan School of Public Health, a diet that emphasizes fruits, vegetables, grains and nuts, while minimizing meat and dairy products, is better for sexual health and reduces urinary incontinence, obstruction and irritation among men being treated for prostate cancer.

The researchers selected study participants from the Health Professionals Follow-Up Study, an ongoing Harvard Chan School investigation begun in 1986. The Harvard study tracks the health of 50,000 plus health professionals. The investigators identified and sorted more than 3,500 prostate cancer patients from the Harvard dataset into five groups that were based on self-reported estimates of how much plant versus animal foods the men said they eat.

The study reported that respondents who ate the most plant-based foods scored 8 to 11 percent better in measures of sexual function compared with the group that consumed the least. Similarly, for urinary health, the high-plant group had 14 percent fewer instances of incontinence, obstruction, and irritation. The men in the high-plant group also scored 13 percent better on hormonal health — their energy level was better, they were less depressed, they had fewer hot flashes.

These findings held up regardless of demographic factors, lifestyle differences (e.g., patient's weight, physical activity) or history of other medical issues such as diabetes. “Adding more fruits and vegetables to their diet, while reducing meat and dairy, is a simple step that patients can take,” said Stacy Loeb, the study's lead author and a professor in the Departments of Urology and Population Health at NYU Langone Health.

Previous research had already found that eating a plant-based diet may reduce the risk of developing the disease in the first place.

The new study is published online in the journal Cancer.