Video: Cancer Treatment: Why a Vegetarian Diet Helps

Prostate Cancer Staging Guide | Transcription

Hi, I'm Dr. Scholz. Let's talk about prostate cancer. 

In this video, we're going to cover dietary practices for prostate cancer patients. I'm not going to try and cover the specifics of what type of diet. I'm going to talk about a general overriding principle, a fairly simple concept, and then there's tons of information you can pursue to learn more about the details. The overriding principle for prostate cancer patients is vegetarianism, vegan diets, avoidance of animal products in the diet. And I contend that it's very hard to change your diet and you're going to need to have a good strong basis for why you're doing this to be able to carry through and be consistent.  There are three broad lines of evidence that all point towards vegan diets for prostate cancer patients. 

The first is my own personal experience with patients in my early practice who would come to me with a passion for going on a diet to treat their prostate cancer. It's not at all unusual; what's unusual is that prostate cancer can be monitored with PSA testing and you can actually see whether or not there's an impact. Men who have rising PSAs after surgery, for example, can have their PSA levels plotted out in a sequential fashion and you can see the growth rate of the tumor when it's untreated. I was rather surprised when men would go on strong vegan diets or macrobiotic diets and their PSAs, which had previously been rising in a steady consistent fashion would stop rising—quickly, within a month—and level off and remain stable as long as they were faithful with their diets. At the same time, these diets were so stringent that the men would lose weight, and I discovered that people who were claiming to be on vegetarian diets and weren't losing weight didn't see much impact on their PSA levels. Prior to patients approaching their prostate cancer this way, I was not a believer, but consistent outcomes like I just described to you changed my thinking about how diet impacts prostate cancer.

The second thing that has reaffirmed this belief that vegetarianism has an inhibitory effect on prostate cancer growth has to do with the metabolic nature of prostate cancer, which is rather different from other types of cancers. Almost everybody's heard that you're supposed to avoid sugar when you have cancer. This is based on some results from what we call PET scans (positron emission tomography scans) where people with say lung cancer or pancreas cancer or lymphoma get a radioactive sugar injected into their bloodstream and they're scanned to where the radioactive sugar concentrates. Well, it concentrates avidly in the tumors—within minutes—so that admonition to avoid sugar if you have one of those other cancer types is very reasonable. Interestingly, with prostate cancer, if you inject radioactive sugar into the system, the prostate cancer couldn't care less. It does not concentrate sugar the way other tumors do. But relatively new technology using radioactive fats (C11 acetate and choline PET scans) or protein (Axumin PET scans) show that prostate cancer feeds on both fats and amino acids—direct derivatives of animal products. So, when people go with a vegetarian type diet, they are avoiding the types of amino acids and proteins that are typical in animal tissue and that's what prostate cancer cells are made out of. This is a very good explanation for why these vegan diets are causing an inhibitory effect on the growth of prostate cancer cells as reflected in how fast the PSA is rising. 

There's a third line of evidence that says the exact same thing, and this has to do with a book written by Dr. Colin Campbell called "The China Study." [It is based on] extensive multi-million  dollar research in China looking at dietary patterns in all cancers including prostate cancer. Dr. Campbell's studies show that the regions of China where people were eating very small amounts of animal protein has much lower cancer rates including prostate cancer. These studies, again, were not designed to answer this question, they were just looking, generally speaking, at dietary patterns and this is what they discovered. The lower the amount of animal protein intake, the lower the incidence of cancers including prostate cancer. 

So three separate lines of evidence all point towards avoiding animal protein for patients who have prostate cancer. So is this something that everyone with prostate cancer has to do? We have to remember that there are many types of indolent low-grade prostate cancers that don't even behave like cancers. I think it's a little bit overboard to say that someone has to radically alter their lifestyle for the management of these Gleason 6 tumors for men on active surveillance. But the other, more advanced—the Royal stage of prostate cancer—when people have metastatic disease, I think it makes a lot of sense to take diet seriously and do your best to avoid animal protein intake altogether.