Exercise & Prostate Cancer Risk

There is an increasing body of research evidence tothe extra step of conducting 7-day physical activity
suggest that many cases of cancer can be preventedevaluations to verify that the study's participants
through lifestyle and diet modifications. Indeed, evenactually engaged in the levels of physically activity that
conservative estimates suggest that more than 60they claimed on the questionnaires. (This additional
percent of new cancer cases could be preventedvalidation step confirmed the accuracy of the
simply by abstaining from unhealthy lifestyle andquestionnaire information supplied by the study's
dietary habits. (More enthusiastic cancer preventionvolunteers.) The incidence of prostate cancer, and the
experts have suggested that 80 percent of cancerdeath rate associated with prostate cancer, among
cases, or more, might be preventable with rigorousthese 45,887 middle-aged and elderly men were then
lifestyle and diet changes.) Given that, in the best case,analyzed at the conclusion of this very large
modern cancer treatment results in the long-termprospective epidemiological study.
survival of only about 60 percent of all cancer patients,When the men who engaged in physical activity at the
and that the survival rate for many of the most lethalhighest levels were compared with those at the
cancers still remains far more dismal, an ounce oflowest levels, some very important differences in
cancer prevention is certainly worth much more than aprostate cancer risk emerged. Overall, very high levels
pound of cancer cure.of physical activity were associated with a 16 percent
As a practicing comprehensive Surgical Oncologist, Ireduction in the risk of developing prostate cancer.
routinely treat patients with highly lethal cancers, manyAdditionally, among the men who spent at least half of
of which are, sadly, incurable by the time they aretheir work days being physically active, the risk of
diagnosed. While not every case of cancer can beprostate cancer was 20 percent lower when
prevented through lifestyle and diet modification, manycompared to men who spent most of their work day
of the terrible, and ultimately fatal, cancer cases that Isitting down. Specifically, and very importantly, there
routinely see might have been prevented withappeared to be a linear and progressive decrease in
reasonably moderate alterations in the way thatprostate cancer risk with each additional 30 minutes of
people choose to live their daily lives.walking or bicycling per day over the course of the
Prostate cancer is the most common non-skin canceradult lifetimes of these men (this linear relationship was
that occurs in men, and the second most commonnoted within a range of 30 to 120 minutes of walking
cause of cancer death in men. In 2009, an estimatedor bicycling per day). Additionally, the risk of developing
192,000 new cases of prostate cancer will beadvanced prostate cancer appeared to be further
diagnosed, and approximately 27,000 men will die oflessened by regular daily physical activity.
this disease. Prostate cancer currently afflicts 1 out ofThe results of this study mirror those of other
every 6 American men during their lifetimes, andhigh-quality cancer prevention studies for other types
accounts for 25 percent of all cancer diagnoses inof cancer (including, most notably, breast cancer). While
men (similar, I might add, to the percentage of breastclinical research studies such as this one are prone to
cancer cases among all cancer cases diagnosed invarious forms of bias, and in particular, biases that arise
women). Most prostate cancers are stimulated tofrom patients "self-reporting" their personal health and
grow and spread by testosterone and otherlifestyle information on study questionnaires, the
androgens produced by the testes, and by otherauthors of this study appear to have taken very
tissues in the body.significant and effective steps to reduce the risk of
The relationship between prostate cancer risk andincluding such biases in the data that they collected
exercise has not been entirely clear, thus far, asfrom these nearly 46,000 men. Therefore, although a
various clinical studies have produced contradictorysmall degree of residual error cannot be completely
findings. Some of these studies have suggested thatexcluded from the results of this impressive
high levels of daily physical activity may reduce the riskepidemiological study, its findings that progressively
of prostate cancer, while other studies have nothigher levels of daily physical activity (and, it must be
confirmed a link between prostate cancer risk andstressed, throughout one's lifetime) are associated with
physical activity levels.a decreasing level of prostate cancer risk are very
A new prospective public health study, just published inlikely to be valid even in the presence of small errors in
the British Journal of Cancer, adds further importantthe study's data (if they exist).
evidence that increased levels of physical activity mayCardiovascular disease remains the most common
indeed reduce the risk of developing prostate cancer.cause of premature death in most societies. Cancer is
In this newly published study, nearly 46,000 menthe number two cause of premature death when
between the ages of 45 and 70 years wereincluding people of all ages, and the number one cause
prospectively followed between 1998 and 2007. All ofof premature death below the age of 80 in the United
these male volunteers completed extensiveStates. Regular exercise, including relatively moderate
questionnaires regarding their daily levels of physicalactivities such as brisk walking or bicycling, have been
activities at 30 years of age and at 50 years of age,shown to significantly reduce the risk of death due to
as well as at the time or their entry into this clinicalcardiovascular disease, as well as, increasingly, the risk
study. These questionnaires specifically includedof developing or dying from multiple different types of
questions regarding walking or bicycling; current waist,cancer. Based upon the results of this well designed
hip and height measurements; education level; cigaretteand well executed prospective clinical research study,
smoking; alcohol consumption; diabetes; family historyit would appear that prostate cancer can be added to
of prostate cancer; and other lifestyle factors. Sixthe list of life-threatening illnesses for which the risk can
predefined activity levels for occupational activity (frombe decreased through regular and frequent physical
"mostly sitting down" to "heavy manual labor"), andactivity (and both at work and at home).
additional predefined categories for time spent on____
different activities, were specifically included in theDisclaimer: As always, my advice to readers is to
questionnaire, such as walking or bicycling ("hardlyseek the advice of your physician before making any
ever" to "more than 90 min per day"), home orsignificant changes in medications, diet, or level of
household work ("less than 1 hour per day" to "morephysical activity
than 8 hours per day"), inactive leisure time ("from 2____
hours per day or less" to "5 hours per day or more"),Dr. Wascher is an oncologic surgeon, a professor of
and active leisure-time exercising ("from less than 1surgery, a cancer researcher, an oncology consultant,
hour per week" to "more than 5 hours per week"). Theand a widely published author
patient volunteers were also queried regarding the___
average number of hours per day they spent sleeping.Copyright 2007 - 2009
Importantly, the researchers conducting this study tookRobert A.