There’s so much fat in bacon grease, you can use it as a fire starter. You can also take a can of Crisco, stick a wick in it, and make an emergency candle. Fat is flammable.
Unfortunately, the same is true inside our bodies, as well: excess body fat is like lighter fluid for prostate cancer. Visceral fat, that “spare tire” around the abdomen, is even worse. It’s not subcutaneous fat – the surface fat you can “pinch an inch” with. It’s deep inside the belly, an evil pillow that settles over and wraps itself around our abdominal organs.
Visceral fat is the Jabba the Hutt of fat: a notorious villain in several important health problems. Visceral fat raises your risk of heart disease, diabetes, metabolic disturbances, dementia, and in women, breast cancer.
Now, for the first time, it’s also been shown to raise your risk of getting prostate cancer – the aggressive kind that needs to be treated. The kind of prostate cancer that kills.
Why is visceral fat so bad? Because it’s like a blobby smokestack, polluting our bodies with its troublesome emissions. “Visceral fat is a living, biologically active entity,” says medical oncologist and molecular biologist Jonathan Simons, M.D., CEO of the Prostate Cancer Foundation. Like the chest-bursting alien in Ridley Scott’s iconic movie, it’s alive! And it’s up to no good.
Among other things, visceral fat messes with your hormones. It lowers testosterone and raises estradiol, a form of estrogen. It churns out inflammatory chemicals called cytokines, which can raise your blood pressure, affect blood clotting, and raise your risk of heart disease and stroke. Cytokines also have a bad influence on your insulin resistance; this rising tide of glucose raises your risk of getting diabetes. Like Charlie Brown’s friend, Pigpen, visceral fat also sheds – not dust, but fatty acids, which go right to the liver. These fatty acids lower your good cholesterol and raise your bad cholesterol.
No one had connected visceral fat to prostate cancer until very recently. In work recently published in Cancer, Boston scientists led by PCF Young Investigator Lorelei Mucci, Sc.D, of Harvard’s T.H. Chan School of Public Health, and Sarah Markt, Sc.D., now at Case Western, investigated the role of body fat distribution and the risk of clinically relevant prostate cancer, “in light of the different hormonal profiles associated with where adipose (fat) is stored.” You might say that their study, of Icelandic men in the Age, Gene/Environment Susceptibility-Reykjavik Study, has just shaken up the apple cart of what we understand about body fat.
The visceral fat we’ve been talking about – the beer-belly look – goes with the “apple” body shape, and this, clearly, is bad, because the fat surrounds so many vital organs. We know that. But what if you’re a “pear?” If you’re a pear shape, you carry your fat lower, in the hips and thighs. This fat is usually subcutaneous fat, usually not thought to be as dangerous as visceral fat.
Guess what? For prostate cancer, thigh fat is bad, too. In this study, the first of its kind, Mucci, Markt, and colleagues found that men with greater visceral abdominal fat as well as men with greater thigh subcutaneous fat are more likely to get advanced or fatal prostate cancer. Visceral fat even raises the risk of advanced or fatal prostate cancer in men with a lower body mass index (BMI – see box).
From 2002 to 2006, 1,832 men underwent baseline testing including CT imaging to determine the exact location of their body fat deposition, measurement of BMI and of waist circumference, and then they were followed for years. Of these men, 172 developed prostate cancer; 43 had high-grade (Gleason 8 or higher) cancer; 41 had advanced cancer (stage T3b or higher) when they were diagnosed, and 31 men had died of prostate cancer by 2015.
Mucci’s team found that among all men in the study, each standard deviation increase in visceral fat and in thigh subcutaneous fat was associated with a 31 percent and 37 percent higher risk of advanced and fatal prostate cancer, respectively. Interestingly, “the associations between visceral fat and aggressive and fatal prostate cancer were stronger among men with a BMI less than 27,” the team reported. “In this group, each standard deviation increase in visceral fat was associated with a two-fold higher risk of advanced and fatal prostate cancer.”
Risk Goes Up with Higher BMI: Mucci and colleagues found that each BMI increase of 5 was associated with a 52 percent higher risk of advanced prostate cancer, and a 56-percent higher risk of fatal prostate cancer. Obese men – with a BMI of 30 or higher (see box) – were 2.5 times more likely to develop advanced disease, and 2.6 times more likely to die of prostate cancer. For about every four-inch increase in waist circumference, the risks of getting advanced prostate cancer and dying of it went up significantly – by 40 percent and 45 percent, respectively.
Eventually, scientists may figure out precisely how obesity and deposition of fat make a man more likely to get aggressive prostate cancer and die of it. In the meantime, this study may lead to important changes in medical practice. In an accompanying editorial, two scientists from Cedars-Sinai Medical Center in Los Angeles, Celina Shirazipour, Ph.D., and Stephen Freedland, M.D., commented that this work helps “highlight the need to examine lifestyle interventions that target fat loss in promoting optimal prostate cancer outcomes.”
In other words, maybe more doctors will look at body fat – and its location on the body – as the higher risk factor for more aggressive disease that it is, and maybe they will help and encourage their patients to lose weight before they develop the worst kind of prostate cancer.
“We are working very hard to save the lives of men who have advanced, aggressive prostate cancer, notes Simons. “To do this, we are trying to understand in depth the genetics and consequences in the biochemistry of the disease, and are looking for ‘’druggable” targets for new classes of drugs, so we can eliminate aggressive cancer clones more effectively. Here is a risk factor for aggressive disease that can be changed! If this applies to you, we want you to know what a difference you can make in your risk of dying of prostate cancer.” For some of the latest science on lifestyle factors that may help reduce risk and improve cancer outcomes, see PCF’s recently published wellness guide: The Science of Living Well, Beyond Cancer.
Note: Stress makes it harder for you to lose weight. If you are stressed, your body makes more cortisol, and cortisol makes your body store more visceral fat. On some ancient level, your body may be thinking: “Oh, no, times are hard! We’re going to starve! Better hang on to this fat!” So, in addition to other ways to lose the fat – exercise and eating a smarter diet with fewer carbs and sugar – you might consider stress management strategies like meditation, relaxation techniques, and deep breathing. It might help your body let go of the fat.
