By Jessica Cote, BS and Anna Mazzucco, PhD
2014

Prostate cancer is the most common cancer and the second leading cause of cancer-related deaths in men in the United States. One in six men will be diagnosed with prostate cancer in his lifetime, with about 90% of cases occurring in men 55 and older, and 71% of deaths occurring in men 75 and older.¹

Even though prostate cancer is a leading cause of death, most prostate cancers are not very dangerous. Two key facts are important to remember:

1. Many older men who aren’t diagnosed with prostate cancer have the disease but will never be harmed by it.
2. Because prostate cancer usually grows very slowly, most men who are diagnosed with prostate cancer will die of something other than prostate cancer. A 2012 study showed that only 16% of men in the U.S. diagnosed with prostate cancer died from this disease.²

Although the death rate is relatively low, it is important to find ways to prevent prostate cancer deaths with treatments that do not have serious side effects.

The cause of prostate cancer is unknown, but older men, African-American men, men who drink high amounts of alcohol, farmers, and men who were exposed to Agent Orange pesticides are all at higher risk.³  The high incidence of prostate cancer in Western Europe and North America is thought to be related to a “Western” diet, which is high in refined grains, other processed foods, and saturated fats.⁴  Meat and dairy products tend to have more saturated fats than other foods, and red meat has more saturated fat than chicken or fish.

Does weight increase the risk?

A 2014 report indicates that being obese can increase a man’s risk of advanced prostate cancer.⁵  The report was based on meta-analyses that combined and analyzed the results of several large studies. The report analyzed the impact of obesity that was measured three ways, by body mass index (BMI), waist circumference, or waist-hip ratio (WHR), and found a similar link.  This suggests that preventing potentially fatal forms of prostate cancer is another reason to maintain a healthy weight.

What is metabolic syndrome and does it increase the risk of dying from prostate cancer?

Metabolic syndrome refers to a group of factors that increase the risk of coronary artery disease, stroke, and type 2 diabetes.⁶ The syndrome includes insulin resistance, obesity (especially extra weight around the middle and upper body parts), high blood pressure, and high levels of blood sugar and fats.

Recent research tells us that metabolic syndrome is also related to prostate cancer deaths. A 2012 study of the medical records of more than 289,000 men, published in 2012 in the journal Cancer, found that the risk of getting prostate cancer didn’t seem to be affected by metabolic factors, but the risk of dying from prostate cancer was.⁷  During a 12-year period, 6,673 men were diagnosed with prostate cancer and 961 died from the disease. Men with a higher BMI, elevated blood pressure, and a high composite metabolic score (from BMI, blood pressure, and blood levels of glucose, cholesterol and triglycerides) were more likely to die from prostate cancer than other men.

The study was well-designed with a large sample size and health information that was collected from patients during many medical exams. However, like most studies, this study wasn’t perfect. Researchers did not record details about the prostate cancer such as tumor stages and patterns of spreading, nor did they consider family history of cancer, medication, socioeconomic status, or other diseases that may have occurred in addition to prostate cancer. All those factors could have influenced the chances of the men dying of prostate cancer. Even so, with hundreds of thousands of men in the study, it is likely that the results should be taken seriously: men can increase their chances of surviving prostate cancer (as well as heart disease) if they reduce metabolic problems.

When we consider this study as well as the 2014 report together, it provides convincing evidence that obesity increases men’s risk of dying of prostate cancer.   While prostate cancer is common among all men, being obese and having the common problems associated with obesity (such as high blood pressure and cholesterol) may make the cancer more aggressive.

What else should men do to lower their risk of getting and dying from prostate cancer?

Cancer screening seems like the best way to reduce the risk of cancer, but that is only true if the screening test is accurate and the treatment is safe and effective.  In 2012, the U.S. Preventive Services Task Force recommended against prostate cancer PSA screening tests for men of any age if they do not present any symptoms of prostate cancer (see: Are Annual Prostate Cancer Screenings Necessary? Should Early Stage Prostate Cancer Be Treated?). The Task Force was convinced that the benefits of PSA-based screening for prostate cancer did not outweigh the harms.⁸

Even though screening isn’t helpful for men with no symptoms of prostate cancer, it could be very effective at saving the lives of men with symptoms.  If you have one or more symptoms of prostate cancer (trouble urinating, blood in the urine, discomfort in the pelvic area), talk to your doctor about getting a PSA or other test for prostate cancer.

Bottom line: If you’re a man over 50, even if you’ve never been diagnosed with prostate cancer and aren’t presenting any symptoms, the latest research tells us it’s a good idea to do the following:

1. Eat a diet low in saturated fats. This means limiting intake of high-fat cheeses and other dairy products and choosing leaner cuts of meat.
2. Watch your intake of sugars and starches– this includes beer, wine and alcohol of all kinds. While 1-2 drinks a day can lower your risk of heart disease and possibly reduce your risk of stroke, more than that can increase your risk of diabetes or related metabolic problems.⁹
3. Weigh yourself regularly.  Most men don’t, but if you weigh yourself frequently, it will help you keep your weight down.  If you gain a few pounds, you should eat less and exercise more until your weight is back down.
4. If you have type 2 diabetes and have been prescribed a special diet or medicine, be sure to stick to it and take your pills as directed.