Welcome back to my weekly blog post! Today, I thought I’d address some of the worlds most dreaded diseases, and cancer tops the list.
The #1 cancer killer in the United States, of both men and women, is lung cancer. But, if you look at the rates of lung cancer around the world, they vary by a factor of ten. If there were nothing we could do to prevent lung cancer, if it just happened at random, you’d assume that the rates everywhere would be about the same. But, since there’s such a huge variation in rates, you assume there’s some contributing cause. Indeed, we now know smoking is responsible for 90% of lung cancer cases. So, if we don’t want to die of the #1 cancer killer, by just not smoking, we can throw 90% of our risk out the window.
Colorectal cancer is the US’ second leading cause of cancer death, for which there’s an even bigger spread. So, it appears colon cancer doesn’t just happen; something makes it happen. Well, if our lungs can get filled with carcinogens from smoke, maybe our colons are getting filled with carcinogens from food. Why do African Americans get more colon cancer than native Africans? Why study Africans? Because colon cancer is extremely rare in native African populations; like more than 50 times lower rates than Americans, white or black.
We used to think it was all the fiber they were eating, however, the modern African diet is highly processed, low in fiber, and yet there has been no dramatic increase in colon cancer. And we’re not just talking low fiber intake, we’re talking United States of America-low, down around half the recommended daily allowance. Yet colon disease still remains rare in Africa; still 50 times less colon cancer.
Maybe it’s because they’re thinner and exercise more? No, they’re not, and no, they don’t. If anything, their physical activity levels may now be even lower. So if they’re sedentary like us, eating mostly refined carbs, few whole plant foods, little fiber—like us, why do they have 50 times less colon cancer? Well, there is one big difference.
The diet of both African-Americans and Caucasian-Americans is rich in meat, whereas the native Africans’ diet is so low in meat and saturated fat they have total cholesterol levels averaging 139, compared to over 200 in the U.S.
So yes, they don’t get a lot of fiber anymore, but they continue to minimize meat and animal fat consumption, supporting evidence that perhaps the most powerful determinants of colon cancer risk are the levels of meat and animal fat intake. So, why do Americans get more colon cancer than Africans? Maybe, the rarity of colon cancer in Africans is associated with low animal product consumption.
It turns out, up to 12 grams of protein a day can escape digestion, and when it reaches the colon, it can be turned into toxic substances, like ammonia. This degradation of undigested protein in the colon is called putrefaction; so, a little meat can actually end up putrefying in our colon. The problem is that some of the by-products of this putrefaction process can be toxic.
The same thing happens with other animal proteins. If you eat egg whites, for example, some of that can putrefy, too. But, there’s protein in plants as well. The difference is that animal proteins tend to have more sulfur-containing amino acids like methionine (which is found most concentrated in fish and chicken, and then eggs, less in beef and dairy, and much less in plant foods), which can be turned into hydrogen sulfide in our colon. Hydrogen sulfide is the rotten egg gas that, over and above its objectionable odor, can produce changes in the colon that increase cancer risk.
Now, there is a divergence of opinion as to whether it’s the animal fat, cholesterol, or animal protein that is most responsible for the increased cancer risk, as all three have been shown to have carcinogenic properties. But, it may not really matter which component is worse, as a diet rich in one is usually rich in the others.
The protein does more than just putrefy, though. Animal protein consumption causes an increase in blood levels of a cancer-promoting growth hormone called IGF-1. But, remove meat, egg whites, and dairy proteins from our diet, and our bloodstream can suppress cancer cell growth about eight times better.
The link between animal protein and IGF-1 may help explain why those eating low-carb diets tend to die sooner, but not just any low-carb diet; specifically, those based on animal sources, whereas vegetable-based low-carb diets are associated with a lower risk of death. But low-carb diets are high in animal fat as well as animal protein, so how do we know it wasn’t the saturated fat and cholesterol that were killing people off, and it had nothing to do with the animal protein?
What we would need is a study that just follows a few thousand people and their protein intake for 20 years or so, and sees who lives longest, who gets cancer, and who doesn’t? But, there’s never been a study like that…until now.
6,000 men and women over age 50, from across the U.S, were followed for 18 years, and those under age 65 with high protein intake had a 75% increase in overall mortality and a fourfold increase in the risk of dying from cancer. But, not all proteins. Specifically, animal proteins. These associations were either abolished or attenuated if the proteins were plant-derived. This all makes sense, given the higher IGF-1 levels in those eating excess protein. Eating animal protein increases IGF-1 levels, which increases cancer risk.
The sponsoring university sent out a press release with a memorable opening line: “That chicken wing you’re eating could be as deadly as a cigarette,” explaining that eating a diet rich in animal protein during middle age makes you four times more likely to die of cancer than someone with a low-protein diet—a mortality risk factor comparable to smoking. And when they say low-protein diet, what they actually mean is just getting the recommended amount of protein.
Almost everyone is going to have a cancer cell or pre-cancerous cell in them at some point. The question is: does it progress? That may depend on what we eat. See, most malignant tumors are covered in IGF-1 receptors, but if there’s less IGF-1 around, they may not be able to progress.
And, it wasn’t just more deaths from cancer. Middle-aged people who eat lots of proteins from animal sources were found to be more susceptible to early death in general. Crucially, the same did not apply to plant proteins like beans, and it wasn’t the fat, but the animal protein, that appeared to be the culprit.
But if doctors just presume people won’t eat this way, it may end up being a self-fulfilling prophecy. Just like smoking doctors are less likely to tell their patients to stop smoking, and couch potato docs are less likely to counsel exercise or things like more fruits and vegetables, we need to role model healthy behavior. This greatly enhances our credibility and effectiveness. Gone are the days of traditional authority when the fat physician, dropping cigarette ash down his gravy-stained vest, could credibly prescribe a change in behavior.
One reason why plant-based diets could save so many millions is because the #1 killer risk factor in the world is high blood pressure, laying to waste nine million people every year. And in the United States, killing off more than a thousand people a day; 400,000 Americans dead every year.
As a Health Coach I empower clients to choose health-promoting behaviors that work for them. I raise awareness and offer support as clients move in their own bio-individual ways toward the greater health they want for themselves. My coaching hopefully leads to long-term behavior change to enhance my clients overall quality of life.
Looking to work with me? Contact me here: Joana.firstname.lastname@example.org