In my last post, we looked at some of the connections between the environment, diet, and cancer development. We also examined how similar cancer is to the body’s reaction to an injury, as if it were healing a damaged or wounded organ in a deranged way.
Today, I’ll continue some of my thoughts about why the cancer rates are so high these days, for dogs, humans, and other animals.
We have discussed in the Guide and here on this blog the effects of estrogen disruptors, which are chemicals that mimic the effects of hormones, most commonly estrogens. Estrogen is a pretty common stimulatory signalling molecule for cancers, especially when other things are also stimulating cancer growth. Its is odd that these compounds like BPA which are found in many plastics (food containers, plastic liners of cans, etc), pesticides, unmetabolized birth control pill residues from water treatment plants, work their harmful magic in low doses instead of high doses. And there is now yet another resurgence in interest about the effects of estrogen disruptors.
Then we have the old fatty acid issue. The short story is this: too much of certain fats (omega-6 fatty acids) create inflammation, increase cancer, and suppress the immune system. These are found in grain fed cow products (red meat, fat, lard), corn, and vegetable oil. It seems the corn feeding of farmed meat animals increases the omega 6 content of the meat, as opposed to grass feeding. Omega 3 fatty acids tend to offset the effects of excessive omega 6 fatty acids, which is why we discuss fish and krill oil in the Guide. 40,000 years ago, based on fossil evidence anyway, our intake of these two kinds of fats was about equal. In other words, we consumed about equal amounts of omega 3 and omega 6 fatty acids. But now humans take in about 10 times as much omega 6 as omega 3, and dogs consume even more. There is a definite link between cancers and microscopic inflammation.
More dietary issues for you to contemplate. Carbs. Very briefly, carbohydrate excess, at least those starches that are converted to sugars easily, feed developing cancer cells. One of the hallmarks of cancers are their preference and need for simple sugars for fuel. This is so common that there is a name for this trait: the glycolytic phenotype. Its also called the Warburg effect. So eating a lot of starch in diets, in short, is like fertilizer for cancer cells. And let’s not forget obesity, affecting about 53% of dogs (which parallels humans btw), leaving them without adequate supplies of adiponectin, an important anti-cancer hormone.
We should not ignore the old immune system. Here we have cancer, a disease characterized by immune compromise, growing in bodies that have crummy immune systems. That’s a bad mix. And why are bodies in the modern world immune compromised? I’d argue its our lifestyles combined with our mental state. Why is this, you might ask? First, we are up, and so are our dogs, often late at night, when we should be sleeping. Light on the retina, particularly blue light late at night, lowers one of the bodies most important cancer-fighting signalling molecules, melatonin. One of the nice things about melatonin is it aids the immune system.
Chronic stress? Of course. Stress hormones, which I believe (but have not measured, so this is speculation) are probably high in dogs as well as humans, suppress the immune system in high amounts. Epinephrine and norepinephrine, signals that are released in the body under high stress conditions, stimulate cancer cells directly.
How about crops? Over the last 40 years, the content of vital trace minerals necessary for normal immune function has slowly dropped, decade by decade. The reason is that the fertilizers used these days usually stimulate bulky rapid growth but lack trace minerals. So repeat growth in plots of land leaches the soil of nice minerals like selenium and zinc which the immune system really needs. So more immune compromise.
Finally, and this is likely a blog player, we humans, our dogs, and other pets don’t take in adequate apoptogens. These are phytonutrients, or nutrients from plants, that increase cell death of cancer cells. The ones in the diet are called the dietary apoptogens. There are over 200 studies in humans and over 20 studies in animals that show eating vegetables and fruits lower cancer rates. There are also many studies in animals that show the dietary apoptogens are chemopreventive, meaning they act like natural preventative chemotherapy. A paper showed that Scotties fed apoptogen-rich vegetables had less bladder cancer (transitional cell carcinoma, which they are prone to).
How would a dog, that does not eat a large amount of vegetables or fruits in its natural diet, get dietary apoptogens (aside from Everpup, that is)? Most of these accumulate in fat, and it turns out that dogs consume the innards of their prey species first, before eating other body parts. Dogs usually consume animals that eat a lot of vegetables, and these animals collect apoptogens in the fat of internal organs, such as the liver.
Even though most have not heard about apoptogens, I have been pushing for their use (for example, by using Apocaps) in dogs with cancer. Slowly, slowly the idea is catching on, and recently James Watson, one of the Nobel prizewinners for his work in discovering the structure of DNA, recently published an article that argued cancer medicine should go in this direction too.
So, how can we pull all of this together? There has been a lot of information in the last two posts, and to be honest I did not even cover everything for fear that the readers of this post would not only be bored, but also depressed. Thus we will cut to the chase at this stage, and summarize my thinking at this time.
First, cancer appears very much like a body healing from an injury in an uncontrolled manner. Bodies are exposed to substances in the air, water, and diet that injury body cells. Whole body inflammation is increased by diet fats and obesity, when normally inflammation should occur in injured body areas. So we have not only ongoing microscopic injury occurring for years and years, but we also have things creating a body that seems like it is injured by mimicking injury physiology. Cell growth control is lost not only because one of the areas damaged are growth genes, but probably more importantly, the environment within the body appears injured, and the signals to heal are turned on excessively.
If we look at the risk factors for cancer, most if not all of them can be reduced to elements of an actual acute injury, chronic injury, or the body’s response to injury, directly or indirectly. This is a critical point in understanding this unified way of looking at cancer. But since the “injury” is not in a single location, there is no actual single wounded area, and the entire body is involved, there is no tissue organization in the activated tissue (cancer) growth. It is chaotic, out of control, and progressive. This systemic injury idea of mine is a key point that is being largely ignored right now in current research.
I hope these last two blog posts are helpful in understanding more about why cancer rates are so high right now.
Dr. Demian Dressler is internationally recognized as “the dog cancer vet” because of his innovations in the field of dog cancer management, and the popularity of his blog here at Dog Cancer Blog. The owner of South Shore Veterinary Care, a full-service veterinary hospital in Maui, Hawaii, Dr. Dressler studied Animal Physiology and received a Bachelor of Science degree from the University of California at Davis before earning his Doctorate in Veterinary Medicine from Cornell University. After practicing at Killewald Animal Hospital in Amherst, New York, he returned to his home state, Hawaii, to practice at the East Honolulu Pet Hospital before heading home to Maui to open his own hospital. Dr. Dressler consults both dog lovers and veterinary professionals, and is sought after as a speaker on topics ranging from the links between lifestyle choices and disease, nutrition and cancer, and animal ethics. His television appearances include “Ask the Vet” segments on local news programs. He is the author of The Dog Cancer Survival Guide: Full Spectrum Treatments to Optimize Your Dog’s Life Quality and Longevity. He is a member of the American Veterinary Medical Association, the Hawaii Veterinary Medical Association, the American Association of Avian Veterinarians, the National Animal Supplement Council and CORE (Comparative Orthopedic Research Evaluation). He is also an advisory board member for Pacific Primate Sanctuary.