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Prostate cancer is the leading cancer health risk for men with new cases being diagnosed every three minutes. At the same time, lifestyle habits can have an enormous impact on our lives and may be the key to reducing these risks.
More specifically, research shows that there are a number of lifestyle factors that are associated with the risks of men developing a lethal type of prostate cancer. Now a new study reveals that adherence to a healthy lifestyle, particularly high physical activity and vigorous exercise, can help to lower these risks.
Led by the assistant professor of urology at the UCSF School of Medicine, Stacey Kenfield, ScD (see above right with her colleague June Chan, left), the new study utilized data from two previous US research studies, effectively tracking the men for more than 20 years. These studies were:
- The Health Professionals Follow-up Study (HPFS) 1986-2010
- The Physicians’ Health Study (PHS) 1982-2010
How the New Study Worked
What researchers did was to develop a lifestyle score for the 42,701 participants in the HPFS and then apply this to the 20,324 participants in the PHS. Points were scored for:
- Non smokers or those who had quit no less than 10 years before
- A body mass index (BMI) of less than 30 kg/m2
- Intense physical activity that was considered vigorous
- A diet that included lots of fatty fish and tomatoes
- A diet that did not include much processed meat
The study used the multivariable Cox proportional hazards regression to do an assessment of the risks of lethal prostate cancer. This result was adjusted to allow for “potential risk factors.” To reduce the possibility of errors, the men in the studies had to be free of diagnosed cancer.
The overall results were published in the Journal of the National Cancer Institute late last year (2015). These showed that there had been 576 lethal prostate cancer “events” in the HPFS group and 337 in the PHS group. Those who scored five to six (rather than zero to one) points in the HPFS group were estimated to have a 68 percent decreased risk of the lethal form of prostate cancer. This statistic was much lower (38 percent) in the PHS group. When only dietary factors were considered, participants scoring three points were found to have a 46 percent decreased risk (HPFS) and 30 percent decreased risk (PHS).
What the Study Tells Us
According to information released by the University of California San Francisco’s news center, the study tracked men in midlife and older for more than 20 years. Ultimately, it revealed that those who did vigorous exercise and followed other “healthy lifestyle habits” (listed above) could cut the risks of developing lethal prostate cancer by as much as 68 percent.
Commenting on the study, Kenfield said that they had estimated if men over the age of 60 had at least five healthy habits, almost half (47 percent) of lethal prostate cancer cases would have been prevented. And if men over 60 exercised at least three hours a week, “to the point of sweating,” more than a third (34 percent) of these cases could have been avoided.
Most types of prostate cancer are “clinically indolent,” which means that they don’t metastasize and are therefore not life threatening. But when men suffer from the aggressive lethal type, the cancer generally invades body organs and bone, and is usually fatal.
Additionally, they found that eating tomatoes at least seven times a week and fatty fish once a week, could cut lethal prostate cancer by 15 and 17 percent respectively. A reduction in consumption of processed meat would cut the incidence of lethal prostate cancer by 12 percent.
Perhaps ironically, smoking was linked to only 3 percent because most older men in the US are understood to be long-term non-smokers.