A diagnosis of prostate cancer is not a death sentence — as the 2.9 million men in the United States alive today who have been diagnosed with the disease will tell you. For those men, and men hoping to reduce their odds of developing prostate cancer, there is an effective and straightforward way to improve your survival rate.

A study from the Harvard Chan School of Public Health has found that a heart-healthy diet, rich in fruits, vegetables, fish, whole grains, and healthy oils, helps a man live longer after being diagnosed with non-metastatic prostate cancer.

Men who ate a typical American diet were 2.5 times more likely to die from their prostate cancer.

Nearly 1,000 doctors who had been diagnosed with prostate cancer were followed for an average of 14 years after their diagnosis. Researchers looked at their diets, health data and eating habits in order to determine if theirs was the typical American diet: meat-centered meals and plenty of fried, carbohydrate-rich foods, or a more prudent, heart-healthy diet.

The typical American — or Western — diet is high in refined grains, high-fat dairy foods, and red and processed meats. It has been linked to many health ailments, everything from heart disease to cancers to Alzheimer’s disease.

The more prudent diet, a Mediterranean-style diet, consists of more fish, whole grains, fruits, vegetables, and legumes, and is associated with a lower risk of health problems.

Doctors who ate a typical American diet were 2.5 times more likely to die from their prostate cancer and 67 percent more likely to die from any other cause. Those who consumed the healthier diet had a 36 percent lower risk of death from all causes.

The study shows a connection, but does not prove cause and effect; and it does provide a starting point for providing men with evidence-based recommendations on how to survive prostate cancer.

“These results are encouraging and add to the scant literature on this area, but it is important to keep in mind that all study participants are physicians and most are white. Therefore it is very important that our results are replicated in other studies with more diverse socioeconomic and racial/ethnic backgrounds,” said lead author Meng Yang of the Harvard Chan School in a statement.

Prostate cancer is the second leading cause of cancer death in American men, and 14 percent of men will be diagnosed with it during their lifetime.

A man may not be able to change the fact that he has prostate cancer, but he can modify his lifestyle to increase his odds of survival. A simple change of diet is preferable to the possible alternative.

The study was published in Cancer Prevention Research.