Health! Wealth! Happiness! I’m Dr. Michael Greger and you’re listening to the Nutrition Facts podcast. And while I can’t promise you all of those things, if you take a listen to the evidence-based nutrition found in this podcast, chances are you’ll learn something that you can use to make a positive change in your diet and in your health. My job here is to bring you the information you need to make that reality possible.
There are lots of ways to fight cancer. So, on today’s show we look at what happens when you put cancer on a plant-based diet.
After Dr. Dean Ornish conquered our #1 killer, he moved on to killer #2. What happens if you put cancer on a plant-based diet? Ornish and colleagues found that the progression of prostate cancer could be reversed with a plant-based diet and other healthy lifestyle behaviors—and, no wonder.
If you drip the blood of those eating the Standard American Diet onto cancer cells growing in a Petri dish, cancer growth is cut down about nine percent. Put people on a plant-based diet for a year, though, the blood circulating within the bodies of those eating plant-based had nearly eight times the stopping power, when it came to cancer cell growth.
Now, this was for prostate cancer—the leading cancer killer specific to men. In women, it’s breast cancer—the #1 cancer killer of young women. So, researchers wanted to repeat the study with women, using breast cancer cells instead. But, they didn’t want to wait a whole year to get the results. Women are dying now. So, they figured, let’s see what a plant-based diet can do after just two weeks against three different types of human breast cancer.
Cancer growth started out powering away at 100%, and then dropped, after eating a plant-based diet for 14 days.
Slowing down the growth of cancer cells is nice. Getting rid of them is even better. This is what’s called apoptosis, programmed cell death. After eating healthy, their own bodies were able to somehow reprogram the cancer cells, forcing them into early retirement.
This is what’s called TUNEL imaging, measuring DNA fragmentation: cell death. So, dying cancer cells show up as little white spots.
The same blood now coursing through these women’s bodies gained the power to significantly slow down and stop breast cancer cell growth—after just two weeks eating a plant-based diet.
What kind of blood do we want in our body? What kind of immune system? Do we want blood that just kind of rolls over when new cancer cells pop up? Or, do we want blood circulating to every nook and cranny in our body, with the power to slow down and stop it?
Now, this dramatic strengthening of cancer defenses was after 14 days of a plant-based diet, and exercise. They had these women out walking 30 to 60 minutes a day. Well, if you do two things, how do you know what role the diet played? So, researchers decided to put it to the test.
Plant-based diet, and walking—that’s the kind of cancer cell clearance you get. Compare that to the cancer-stopping power of your average sedentary American, which is basically nonexistent.
The researchers wanted to know, if you exercise hard enough, if you exercise long enough, can you rival some strolling plant-eaters? And the answer is, exercise helped—no question. But, literally 5,000 hours in the gym was no match for a plant-based diet.
So, the reason one of the largest prospective studies on diet and cancer found the incidence of all cancers combined was lower among those eating more plant-based may be because they’re eating less animal protein, less meat, egg white, and dairy protein—so, end up with less IGF-1, which means less cancer growth.
How much less cancer? Middle-aged men and women with high protein intakes had a 75% increase in overall mortality, and a four-fold increase in the risk of dying specifically from cancer. But, not all proteins—specifically animal protein; which makes sense, given the higher IGF-1 levels.
The academic institution 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 proteins during middle age makes you four times more likely to die from cancer—a mortality risk factor comparable to smoking cigarettes.
What was the response to the revelation that diets high in meat, eggs, and dairy could be as harmful to health as smoking? Well, one nutrition scientist replied that it was potentially dangerous to compare the effects of smoking with the effects of meat and dairy. Why? Because a smoker might think, why bother quitting smoking if my ham and cheese sandwich is just as bad for me? So, better not tell anyone about the whole animal protein thing.
That reminds me of a famous Philip Morris cigarette ad that tried to downplay the risks by saying, hey, you think secondhand smoke is bad (increasing the risk of lung cancer 19%). Well, hey, drinking one or two glasses of milk every day may be three times as bad (62% higher risk of lung cancer). Or, doubling your risk frequently cooking with oil. Or, tripling your risk of heart disease by eating non-vegetarian. Or, multiplying your risk six-fold by eating lots of meat and dairy. So, they conclude, let’s keep some perspective here! “…[T]he risk of lung cancer from second-hand smoke” may be “well below” that of other “everyday…activities.” So, breathe deep.
That’s like saying, don’t worry about getting stabbed, because getting shot is so much worse. Uh, how about neither? Two risks don’t make a right.
Of course, you know, Philip Morris stopped throwing dairy under the bus once they purchased Kraft foods. Just sayin’…
Can the beta-glucan fiber in brewer’s, baker’s, and nutritional yeast improve wound healing and, potentially, anti-cancer immunity? Here’s the research.
In an article entitled “The Treatment of Inoperable Cancer”, it was noted that “200 years ago, it was observed that a certain number of malignant growths disappeared after an attack of [a type of Strep infection]”—and that was 200 years before 1901, when this was published. A disproportionate number of cases of spontaneous tumor regressions have followed various infections. The thought is that an infection may kind of so rile up the immune system, the cancer may get caught in the cross-fire—a phenomenon that may have inspired healers dating back to the ancient Egyptians, thousands of years ago.
But, you don’t know until you put it to test—though it wasn’t formally studied until the 1800s, when doctors started intentionally infecting cancer patients. The most famous proponent was William Coley, the so-called “Father of Immunotherapy,” at what would eventually become Memorial Sloan Kettering. He “was convinced that having a severe infection could cause cancer to regress.” So, with “a great deal of courage,” he started injecting cancer patients. The problem, of course, is that causing infections is quite dangerous, and “two of his patients died.” However, their tumors did shrink!
If only there was a way we could boost the immune system without killing people. Well, that’s the theory behind therapeutic cancer vaccines—one of which has been in practice for decades: squirting a weakened bovine tuberculosis bacteria into the bladders of patients with bladder cancer, to make the immune system attack; boosting long-term survival up to 36%.
Okay, but is there something we can eat that can boost immune function? In my videos on countering stress-induced immune suppression and preventing common childhood infections, I reviewed evidence about a type of fiber in baker’s, brewer’s, and nutritional yeast, called “beta-glucans…[which] are considered immunomodulatory compounds suggested to enhance the defense against infections” and, potentially, cancer.
Beta-glucans themselves do not appear to have a direct cytotoxic effect in terms of killing cancer cells, but may boost anti-tumor immunity by activating our immune cells. For example, if you take freshly excised tumors of breast cancer patients, and let loose natural killer cells upon them, they can kill off a small percentage of the tumor cells. But, first prime them in vitro with some yeast beta-glucans, and they become five times more effective at killing cancer cells. What if you just eat it, though?
When 23 women with metastatic breast cancer were given just a 16th of a teaspoon of nutritional yeast worth of beta-glucans, they experienced a 50% increase in the number of monocyte white blood cells in their bloodstream (which are part of our natural defenses), as well as a significant increase in their activation. But, it was just a two-week study. The clinical significance of this finding is unclear. What we want to know is if they actually live longer.
The only English-language, randomized, double-blind, placebo-controlled trial of breast cancer patients and beta-glucan was more of a wound-healing study, where they found that the women taking beta-glucan healed so much faster after surgery that the tubes could be removed from their chests and armpits—in some cases, days earlier. This was the first clinical study to demonstrate improved wound healing using oral beta-glucans. The other two—showing benefits for pediatric burns and leg ulcers—were performed using topical beta-glucan preparations: putting it on the skin directly, something that did not appear to reverse precancerous skin lesions better than placebo. But, that’s because the placebo cream worked so well, too. “Both groups showed a…significant reduction.” They speculated that “[s]ince each patient…acted as their own control,” putting the beta-glucan cream on one arm, and the placebo cream on the other, that the application of beta-glucans on one arm may have been absorbed into the system, and helped on the other arm, given that systematic effects have been noted following topical administration.
But, what effect might oral beta-glucans have on the progression of internal cancers? Yeah, oral yeast beta-glucans can cause dramatic tumor shrinkage—in mice, but there appears to be only one human study published in English. Twenty patients with advanced cancer on chemo were given a beta-glucan supplement in an open label, uncontrolled trial. “Sixty percent of the patients [supposedly] reported a sense of well-being while taking the [beta]-glucan, and asked to remain on the treatment…after the completion of the study.” But, that just sounds like classic placebo effect. Same thing with reporting being less tired, but this is interesting: “one patient with lymphoma and [enlarged lymph nodes in the neck] who delayed his standard chemotherapy for 4 weeks during the study…noted a marked reduction in the size of the nodes while taking the [supplement] alone.” So, this, you know, one kind of anecdotal case is interesting, especially since there are no side effects, but not exactly revolutionary.
In Japan, there have been more than 20 randomized, controlled trials on the use of beta-glucans as an adjunct cancer treatment, which evidently show an enhancement of chemo or radiation therapy, resulting in “a positive effect on the survival and quality of life…” For example, there was evidently a study on taking a yeast beta-glucan supplement to help “cancer relapse after surgery. There were no relapses in the treated group compared to [about one in five] in the control group.” Even more intriguing, yeast beta-glucans for inoperable cancer patients—end-stage cancer, since only about one in 20 patients made it three months. And by six months, they were all dead, “whereas in the treated group, [most] survived for more than 3 months”—not one in 20, but most, “and 43% were still alive after 6 months.”
Now evidently, it’s not clear how patients were divvied up into treatment vs. control groups. If they weren’t randomly assigned, they may have inadvertently cherry-picked healthier patients for the treatment group, which could explain the results. Now, I’ve looked for this study everywhere so I could get it translated, but even the National Library of Medicine couldn’t find it. If anyone out there can, though, I’ll do a follow-up video. But, the amount of beta-glucan they used is what you’d find in a single pinch of nutritional yeast, which would cost less than a penny. And the only side effect would be tastier popcorn. So, why not give it a try?
If you’re wondering which nut – as in edible nut – fights cancer better, you’re in the right place. In this story we look at the special properties of almonds, Brazil nuts, cashews, hazelnuts, macadamias, peanuts, pecans, pine nuts, pistachios, and walnuts. Guess which nut is best?
In my video on nuts and breast cancer prevention, I featured data from the Harvard Nurses’ Study, suggesting early nut consumption may be “a viable means for breast cancer prevention.” A follow-up study involving the daughters of the nurses corroborated the findings. Those eating more peanut butter, nuts, beans, lentils, soybeans, or corn were found to just have a fraction of the risk for fibrocystic breast disease, which places one at higher risk for cancer. And, the protective effects were found to be strongest for those most at risk—the ones with a family history of breast cancer.
A new study even found just two handfuls of nuts a week may protect against pancreatic cancer, one of our deadliest cancers. We’re not sure why they work. Nuts are described as “nutritionally precious,” packed with all sorts of goodies, which may explain some of the mechanisms by which nut components “induce cancer cell death,” and inhibit cancer growth and spread in vitro.
But, which nuts work the best? In my video “#1 Anticancer Vegetable,” we learned that two classes of vegetables—the broccoli family vegetables and the garlic family vegetables—most effectively suppressed cancer cell growth. Then in “Which Fruit Fights Cancer Better?”, cranberries and lemons took the title. What about nuts? Well, in terms of antioxidant content, walnuts and pecans steal the show. Twenty-five walnuts [have] the antioxidant equivalent of eight grams of vitamin C. That’s like the vitamin C found in a hundred oranges. Ah, but how do they do against cancer?
Pine nuts, cashews, and macadamia nuts start pulling away from the pack. Almonds appear twice as protective, halving cancer cell growth at only half the dose. But these final three are the winners, walnuts and pecans, with the bronze going to peanuts.
This was nuts versus human liver cancer cells, like they did in the fruit study. They found similar results pitting nuts against human colon cancer cells—which is particularly useful, since ingested nuts would come in direct contact with colon cancer tumors in the real world, whereas for something like breast cancer, even if nuts suppressed breast cancer growth in a Petri dish, that doesn’t necessarily mean nut consumption would suppress breast cancer growth in the breast, since the protective nut compounds might not even get absorbed into the bloodstream.
To test that, you’d have to like design an experiment where you drip the blood of nut-eaters versus non-nut-eaters on breast cancer. And, that’s exactly what researchers at Penn State recently did. And, they wanted to know what it was about nuts that was so protective. So, they fed people whole walnuts, just the walnut oil, or just the walnut skins and then dripped their blood on human breast cancer cells in a Petri dish over the next six hours. And, the blood of those eating walnuts suppressed the growth of human breast cancer—but just the oil or just the skin didn’t seem to.
And, most importantly, these data suggest that some “components of walnuts are [indeed] absorbed, circulate in the [blood], and [can] affect…breast cancer cell proliferation.”
To see any graphs, charts, graphics, images or studies mentioned here, please go to the Nutrition Facts podcast landing page. There, you’ll find all the detailed information you need – plus links to all the sources we cite for each of these topics.
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Thanks for listening to Nutrition Facts. I’m Dr. Michael Greger.
This is just an approximation of the audio content, contributed by Allyson Burnett.