"A study that tracked tens of thousands of midlife and older men for more than  years has found that vigorous exercise and other healthy lifestyle habits may cut their chances of developing a lethal type of prostate cancer by up to  percent. While most prostate cancers are clinically indolent meaning they do not metastasize and are nonlifethreatening a minority of patients are diagnosed with aggressive disease that invades the bone and other organs and is ultimately fatal. Lead author Stacey Kenfield ScD of UCSF and a team of researchers at UCSF and Harvard focused on this variant of prostate cancer to determine if exercise diet and smokefree status might have lifesaving benefits. In the study published today Nov.   in the Journal of the National Cancer Institute the researchers analyzed data from two U.S. studies the Health Professionals FollowUp Study that tracked more than  males ages  to  from  to  and a second the Physicians Health Study that followed more than  males ages  to  from  to . To gage the effects of lifestyle habits the researchers developed a score based on the results of the health professionals survey then applied it to the physicians study. They assigned one point for each affirmative response to questions about regular intense exercise that induced sweating body mass index BMI under  tobaccofree status for a minimum of  years high intake of fatty fish high intake of tomatoes and low intake of processed meat. To reduce error participants had to be free of diagnosed cancer at the start of the study and a fouryear lag was imposed to rule out those who unknowingly had lethal prostate cancer which was determined by evidence of prostate cancer death or metastasis to the bones or other organs excluding the lymph nodes. Cases were confirmed through medical records and pathology reports and cause of death was determined by death certificate and medical record and secondarily by next of kin. Vigorous activity trumps other lifestyle factors The researchers identified  cases of lethal prostate cancer in the health professionals group and  cases in the physicians group. Participants with  to  points in the health professionals group had a  percent decreased risk of lethal prostate cancer and a  percent decreased risk was observed in the physicians group for the same comparison. For dietary factors alone men with three points versus those with zero points had a  percent decreased chance of developing lethal prostate cancer in the health professionals group. In the physicians group this decrease was  percent. While there were fewer cases and less detailed data collected in the physicians study the score was similar in both populations indicating the potential benefit of healthy lifestyle habits in warding off lethal prostate cancer said the authors. We estimated that  percent of lethal prostate cancer cases would be prevented in the United States if men over  had five or more of these healthy habits said Kenfield assistant professor in the Department of Urology at UCSF Medical Center and formerly of the Department of Medicine at Harvard Medical School in Boston where the study was initiated. Its interesting that vigorous activity had the highest potential impact on prevention of lethal prostate cancer. We calculated the populationattributable risk for American men over  and estimated that  percent of lethal prostate cancer would be reduced if all men exercised to the point of sweating for at least three hours a week Kenfield said. The researchers also calculated that lethal prostate cancer among American men over  would be cut by  percent if they consumed at least seven servings of tomatoes per week and that  percent would be spared this diagnosis if they consumed at least one serving of fatty fish per week. Reducing intake of processed meats would cut the risk by  percent they reported. In contrast the populationattributed risk for smoking was  percent largely because the majority of older American men are longterm nonsmokers. Lifestyle changes also prevent heart disease diabetes This study underscores the ongoing need for more effective prevention measures and policies to increase exercise improve diet quality and reduce tobacco use in our population said senior author June M. Chan ScD from the departments of Urology and Epidemiology and Biostatistics at UCSF. It takes cooperation and effort from multiple areas like insurance companies employers policy makers and city planners to figure out how to creatively support and encourage more exercise into most busy adults working day. These lifestyle habits align with other recommendations to prevent diabetes and heart disease. About one man in seven will be diagnosed with prostate cancer during his lifetime making it the most frequently diagnosed cancer in the United States excluding nonmelanoma skin cancer. According to the American Cancer Society in  there will be approximately  cases of prostate cancer and approximately   deaths.  This study was supported by grants from the Prostate Cancer Foundation and the National Institutes of Health. Coauthors are Erin Van Blarigan ScD of the departments of Urology and Epidemiology and Biostatistics at UCSF Howard Sesso ScD MPH Edward Giovannucci MD ScD Meir Stampfer MD DrPH and Julie Batista ScD all of Harvard T.H. Chan School of Public Health Harvard Medical School and Brigham and Womens Hospital Mary Kathryn Downer and Jaquelyn Jahn both of Harvard T.H. Chan School of Public Health and Brigham and Womens Hospital. About UCSF UCSF is a leading university dedicated to transforming health worldwide through advanced biomedical research graduatelevel education in the life sciences and health professions and excellence in patient care. Founded in  as a medical college UCSF now includes topranked graduate schools of dentistry medicine nursing and pharmacy a graduate division with worldrenowned programs in the biological sciences a preeminent biomedical research enterprise and toptier hospitals UCSF Medical Center and UCSF Benioff Childrens Hospitals. Please visit http"