Men who have been diagnosed with prostate cancer are more likely to die from a preventable disease like heart disease rather than the cancer itself, a new study from Harvard says.

"Our results are relevant for several million men living with prostate cancer in the United States. We hope this study will encourage physicians to use a prostate cancer diagnosis as a teachable moment to encourage a healthier lifestyle, which could improve the overall health of men with prostate cancer, increasing both the duration and quality of their life," said Mara Epstein, a postdoctoral researcher at Harvard School of Public Health (HSPH) and lead author of the study.

In the present study, researchers analyzed the cause of death of more than 490,000 men from the U.S. diagnosed with prostate cancer and over 210,000 men from Sweden who had the cancer.

They found that the risk of dying from prostate cancer declined over the years but dying from other diseases like heart disease remained constant with time.

Only 35 percent of Swedish men and about 16 percent of US men diagnosed with prostate cancer died due to the disease. Incidence of death five years post diagnosis was about 29 percent in Sweden and about 11 percent in the U.S.

Researchers found that the risk of dying from prostate cancer was higher in older men rather than younger men.

According to the researchers, adopting a healthy lifestyle is probably more beneficial than the cancer therapy.

"Our study shows that lifestyle changes such as losing weight, increasing physical activity, and quitting smoking, may indeed have a greater impact on patients' survival than the treatment they receive for their prostate cancer," said Hans-Olov Adami, professor of epidemiology at HSPH and senior author of the study.

Researchers say that the higher rate of prostate cancer diagnosis is due to the use of the prostate-specific antigen (PSA) test. The test diagnoses the presence of non-risk cancers as well.

The US Preventive Services Task Force (USPSTF) had announced in May that it recommends against PSA-based screening for prostate cancer.

The study was published in the Journal of the National Cancer Institute.