How Not to Die from Cancer

After Dr. Dean Ornish conquered our number-one killer, heart disease, he moved on to killer number-two. What happens if cancer is put on a plant-based diet? Ornish and colleagues found that the progression of early-stage prostate cancer could be reversed with a plant-based diet and other healthy lifestyle behaviors.

If the blood of those eating the Standard American Diet is dripped onto cancer cells growing in a petri dish, cancer growth is cut down about 9 percent. And if they’ve followed a plant-based diet for a year? Their blood can slash cancer growth by 70 percent. So the blood circulating thgouhout the bodies of those eating plant-based diets had nearly eight times the stopping power when it came to suppressing cancer cell growth.

That was for cell growth of prostate cancer, the leading cancer-killer specific to men. In younger women, breast cancer is the top cancer-killer. Researchers wanted to repeat the study with women using breast cancer cells, but they didn’t want to wait a whole year to get the results. Women are dying now. So they figured they’d see what a plant-based diet could do after just two weeks against three different types of human breast cancer.

As you can see in my video How Not to Die from Cancer, the study showed cancer growth started out at 100 percent, but then dropped after the subjects ate a plant-based diet for 14 days. A layer of breast cancer cells was laid down in a petri dish, and then blood from women eating the Standard American Diet was dripped on it. As you can see in the video, even the blood of women eating pretty poor diets had some ability to break down cancer. After just two weeks of eating healthfully, though, blood was drawn from those same women—so they effectively acted as their own controls—and was dripped on a new carpet of breast cancer cells. You can see for yourself that only a few individual cancer cells remained. Their bodies cleaned up. After only 14 days on a plant-based diet, their bloodstream became that much more hostile to cancer.

Slowing down the growth of cancer cells is nice, but getting rid of them all together is even better. This is what’s called apoptosis, programmed cell death. After eating healthfully, the women’s own bodies were able to somehow reprogram the cancer cells, forcing them into early retirement.

In my video, you can see what’s called TUNEL imaging, which allows researchers to measure DNA fragmentation, or cell death. With this technology, dying cancer cells appear as little white spots. From the start of the study, you can see one small white speck in the upper left of the image, showing that the blood of an average woman on a typical American diet can knock off a few breast cancer cells. After 14 days of healthy, plant-based living, however, her blood turned that one small white speck into a multitude of white spots. It’s as if she’s an entirely different woman inside! The same blood now coursing through these women’s bodies gained the power to significantly slow down and even stop breast cancer cell growth after just two weeks of 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 rolls over when new cancer cells pop up, or do we want blood circulating to every nook and cranny of our body with the power to slow down and stop them?

The dramatic strengthening of cancer defenses shown in the study was after 14 days of a plant-based diet—and exercise.The researchers had the women walking 30 to 60 minutes a day. Given there were two factors, how do we know what role the diet played? Researchers decided to put it to the test.

In my video, you can see a chart that first shows how blood taken from those who ate a plant-based diet and had a routine of mild exercise, such as walking every day, over an average of 14 years, exhibited significant cancer cell clearance. The researchers then compared the substantial cancer-stopping power of plant eaters to that of an average sedentary American, which you can see is basically nonexistent.

The researchers also analyzed a third group. Instead of 14 years on a plant-based diet, they had 14 years on a Standard American Diet, but they also had 14 years of daily, strenuous, hour-long exercise, like calisthenics. They wanted to know if you exercised hard enough and long enough could you rival some strolling plant eaters.

The answer? There’s no question that exercise helped, but literally 5,000 hours in the gym was no match for a plant-based diet.

Once again using TUNEL imaging to analyze cancer cell death, the researchers found that even if you are a couch potato eating fried potatoes, your body isn’t totally defenseless. Your bloodstream can kill off some cancer cells, which you can see in my video as a couple white spots in the first image of that series. If you exercise for 5,000 hours, you can kill many more cancer cells, evidenced by the many more white specks appearing throughout that image. But nothing appears to kick more cancer tush than a plant-based diet, as that image is filled with white spots indicating cancer cells killed off.

Why is this the case? We think it’s because animal proteins, such as meat, egg white, and dairy protein, increase the level of insulin-like growth factor-1 (IGF-1), a cancer-promoting growth hormone involved in the “acquisition or progress of malignant tumors.”

In my video, you can see the results of a study that nailed IGF-1 as the villain. Just as in the previous studies, subjects went on a plant-based diet and cancer-cell growth dropped, while cancer-cell death shot up. This experiment, however, had a kicker: It added back to the cancer just the amount of IGF-1 that had been banished from your body as a result of eating and living healthier. In doing so, it effectively erased the “diet and exercise” effect. It’s as if the subjects had never started eating healthfully at all, with the cancer-cell growth rates and death rates returning to the same levels as before the plant-based diet intervention.

The reason one of the largest prospective studies on diet and cancer found “the incidence of all cancers combined was lower among vegetarians than among meat eaters” may be because they eat less animal protein, and thereby end up with less IGF-1, which means less cancer growth.

How much less cancer growth? A study found that middle-aged men and women with high protein intakes had a 75 percent increase in overall mortality and a fourfold increase in the risk of dying specifically from cancer. Does the protein source matter? Yes. It was specifically animal protein, which makes sense, given their higher IGF-1 levels.

The academic institution where the study was done sent out a press release with a memorable opening line: “That chicken wing you’re eating could be as deadly as a cigarette.” It went on to explain 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.”

What was the response to the revelation that diets high in meat, eggs, and dairy could be as harmful to health as smoking? One nutrition scientist replied it was “‘potentially even dangerous’ to compare the effects of smoking with the effect of meat and cheese,” but why? Because, they argued, a smoker might think “‘why bother quitting smoking if my cheese and ham sandwich is just as bad for me?’”

This reminds me of a famous Philip Morris cigarette ad that tried to downplay the risks of second-hand smoke. The ad included a chart with “everyday activities” and “reported relative risk,” in an attempt to say second-hand smoke wasn’t all that bad. The chart showed that while it increases the risk of lung cancer by 19 percent, drinking one or two glasses of milk every day may be three times as bad with a 62 percent higher risk of lung cancer. Lung cancer risk could be doubled if you frequently cook with oil, and heart disease risk tripled if you eat non-vegetarian or multiplied six-fold by eating lots of meat and dairy. Philip Morris’s conclusion? “Let’s keep a sense of perspective.” The “risk of lung cancer from second-hand tobacco smoke [was put] well below the risk reported by other studies for many everyday items and activities.”

That’s like saying, “Don’t worry about getting stabbed, because getting shot is so much worse.” Two risks don’t make a right.

Of course, you’ll note Philip Morris stopped throwing dairy under the bus once it purchased Kraft Foods.


The first time someone visits NutritionFacts.org can be overwhelming. With videos on more than 2,000 health topics, where do you even begin? Imagine stumbling onto the site not knowing what to expect and the new video-of-the-day is about how a particular spice can be effective in treating a particular form of arthritis. It would be easy to miss the forest for the trees, which is precisely why I created a series of overview videos that are essentially taken straight from my live, hour-long 2016 presentation How Not to Die: Preventing, Arresting, and Reversing Our Top 15 Killers.

The other videos in this overview series are:

Inspired to learn more about the role diet may play in preventing and treating cancer? Check out these other popular videos on the topic:

I’ve also produced an entire series on mammograms. You can find all of those videos here.

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

How Not to Die from Heart Disease

The most likely reason most of our loved ones will die is heart disease. It’s up to each of us to make our own decisions about what to eat and how to live, but we should make these choices consciously by educating ourselves about the predictable consequences of our actions.

Atherosclerosis, or hardening of the arteries, begins in childhood. The arteries of nearly all kids raised on the standard American diet already have fatty streaks marking the first stage of the disease—by the time they are ten years old. After that, the plaques start forming in our 20s, get worse in our 30s, and then can start killing us off. In our heart, it’s called a heart attack, and in our brain, it can manifest as a stroke. So for anyone  reading this who is older than ten years old, the choice isn’t whether or not to eat healthfully to prevent heart disease—it’s whether or not you want to reverse the heart disease you likely already have.

Is that even possible? When researchers took people with heart disease and put them on the kind of plant-based diet followed by populations who did not get epidemic heart disease, their hope was that it might slow down the disease process or maybe even stop it. Instead, something miraculous happened. The disease actually started to reverse. It started to get better. As I show in my video How Not to Die from Heart Disease, as soon as patients stopped eating artery-clogging diets, their bodies were able to start dissolving away some of the plaque, opening up arteries without drugs and without surgery, suggesting their bodies wanted to heal all along but just were never given the chance. That improvement in blood flow to the heart muscle itself was after only three weeks of eating healthfully.

Let me share with you what’s been called the best-kept secret in medicine: Sometimes, given the right conditions, the body can heal itself. Take, for instance, what happens when you accidentally whack your shin really hard on a coffee table. It gets red, hot, painful, swollen, and inflamed, but it’ll heal naturally if you just stand back and let your body work its magic. What would happen, though, if you kept whacking your shin in the same place, day after day, or three times a day (breakfast, lunch, and dinner)? It would never heal! You might turn to your doctor, complaining of shin pain, and would probably limp out of the office with a prescription for painkillers. You’d still be whacking your shin three times a day, but the pain would be a little duller, thanks to those pills you’d be popping.

It’s similar to people taking nitroglycerine for crushing chest pain. They may get tremendous relief, but they’re not doing anything to treat the underlying cause. Our body wants to come back to health if we let it, but if we keep re-damaging ourselves three times a day, we may never heal.

One of the most amazing things I learned in all my medical training was that within about 15 years after you stop smoking, your lung cancer risk approaches that of a lifelong nonsmoker. Isn’t that amazing? Your lungs can clear out all that tar, and, eventually, it’s almost as if you never smoked at all. Just think, every morning of your smoking life, your body started on that path to healing, until…wham!…you inhaled on that first cigarette of the day, reinjuring your lungs with every puff. In the same way, we can reinjure our arteries with every bite. But, all we have to do all along—the miracle cure—is just stand back, get out of the way, stop re-damaging ourselves, and let our body’s natural healing processes bring us back towards health. The human body is a self-healing machine.

Sure, you could choose moderation and hit yourself with a smaller hammer, but why beat yourself up at all? I don’t tell my smoking patients to cut down to half-a-pack a day. I tell them to quit. Sure, smoking a half pack is better than two packs, but we should try to put only healthy things into our mouths.

We’ve known about this for decades. Take the case of Mr. F.W., for example, as published in 1977 in the American Heart Journal. He had such bad heart disease he couldn’t even make it to the mailbox without crushing chest pain. But he started eating strictly plant-based and a few months later he was climbing mountains without pain.

There are fancy new anti-angina  drugs out now. They cost thousands of dollars a year, but at the highest dose, they may only be able to prolong exercise duration for as long as… 33.5 seconds. It doesn’t seem as though patients choosing the drug route will be climbing mountains anytime soon.

Plant-based diets aren’t just safer and cheaper. They can work better because they let us treat the actual cause of the disease.


The first time someone visits NutritionFacts.org can be overwhelming. With videos on more than 2,000 health topics, where do you even begin? Imagine stumbling onto the site not knowing what to expect and the new video-of-the-day is about how a particular spice can be effective in treating a particular form of arthritis. It would be easy to miss the forest for the trees, which is precisely why I created this series of overview videos that are essentially taken straight from my live, hour-long 2016 presentation How Not to Die: Preventing, Arresting, and Reversing Our Top 15 Killers.

And don’t miss these other videos in this overview series:

Inspired to learn more about the role diet may play in preventing and treating heart disease? Check out these other popular videos on the topic:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations:

How Can Animal Protein Intake Increase Childhood Obesity Risk?

If pregnant crickets are exposed to a predatory wolf spider, their babies will hatch, exhibiting increased antipredator behavior and, as a consequence, improved survival from wolf spider attack. The mother cricket appears to be able to forewarn her babies about the threat when they are still inside her, so they would be pre-adapted to their external environment. This even happens in plants. If you grow two genetically identical plants—one in the sun, one in the shade—the sun-grown plant will produce seeds that grow better in the sun, and the shaded plant will produce seeds that grow better in the shade—even though they’re genetically identical.

What’s happening is called epigenetics, external factors changing gene expression.

Vole pups born in the winter come out growing thicker coats. Vole mothers are able to communicate the season to their babies in utero and tell them to put a coat on even before they’re born. We’re no different. You know how some people have different temperature tolerances, resulting in “battles of the bedroom”? Do you turn the AC on or off? Open the windows? It’s not just genetics. Whether we’re born in the tropics or in a cold environment determines how many active sweat glands we have in our skin.

What does this have to do with diet? As I discuss in my video Animal Protein, Pregnancy, and Childhood Obesity, can what a pregnant woman eats—or doesn’t eat—permanently alter the biology of her children in terms of what genes are turned on or off throughout life?

What happened to the children born during the 1944 – 1945 Dutch famine imposed by the Nazis? They had higher rates of obesity 50 years later. The baby’s DNA gene expression was reprogrammed before birth to expect to be born into a world of famine and conserve calories at all cost. But when the war ended, this propensity to store fat became a disadvantage. What pregnant women eat and don’t eat doesn’t just help determine the birth weight of the child, but the future adult weight of the child.

For example, maternal protein intake during pregnancy may play a role in the obesity epidemic—but not just protein in general. “Protein from animal sources, primarily meat products, consumed during pregnancy may increase risk of overweight in offspring…” Originally, researchers thought it might be the IGF-1, a growth hormone boosted by animal product consumption, that may increase the production of fatty tissue, but weight gain was tied more to meat intake than dairy. Every daily portion of meat intake during the third trimester of pregnancy resulted in about an extra 1 percent of body fat mass in their children by their 16th birthday, potentially increasing their risk of becoming obese later in life, independent of how many calories they ate or how much they exercised.  But no such link was found with cow’s milk intake, which would presumably boost IGF-1 levels just as high.

Given that, perhaps instead of IGF-1, it’s the obesogens in meat, chemicals that stimulate the growth of fatty tissue. “[E]merging evidence demonstrates that environmental factors can predispose exposed individuals to gain weight, irrespective of diet and exercise.” After all, even our infants are fatter, and we can’t blame that on diet and exercise. Animals are fatter, too, and not just our pampered pets—even rats in laboratories and subways are bigger. “The likelihood of 24 animal populations from eight different species all showing a positive trend in weight over the past few decades by chance was estimated at about 1 in 10 million” so it appears something else is going on—something like obesogenic chemicals.

One such candidate is polycyclic aromatic hydrocarbons (PAHs), which are found in cigarette smoke, vehicle exhaust, and grilled meat. A nationwide study of thousands found that the more children were exposed to PAHs, the fatter they tended to be. The researchers could measure the level of these chemicals right out of their urine. Exposure can start in the womb. Indeed, prenatal exposure to these chemicals may cause increased fat mass gained during childhood and a higher risk of childhood obesity.

If these pollutants sound familiar, I’ve covered them before in relation to increasing breast cancer risk in the Long Island Breast Cancer Study Project. So, perhaps they aren’t just obesogens, but carcinogens, as well, which may help explain the 47 percent increase in breast cancer risk among older women in relation to a lifetime average of grilled and smoked foods.

If we look at one of the most common of these toxins, smokers get about half from food and half from cigarettes. For nonsmokers, however, 99 percent comes from diet. The highest levels of PAHs are found in meat, with pork apparently worse than beef. Even dark green leafies like kale can get contaminated by pollutants in the air, though, so don’t forage for dandelion greens next to the highway and make sure to wash your greens under running water.

These are fat-soluble pollutants, so they need lots of fat to be absorbed. It’s possible that even heavily contaminated plant-based sources may be safer, unless you pour lots of oil on your food, in which case the toxins would presumably become as readily absorbed as the toxins in meat.

The good news is they don’t build up in our body. As I show in my video, if we expose people to barbecued chicken, they get a big spike in these chemicals—up to a hundred-fold increase—but our body can get rid of them within about 20 hours. The problem, of course, is that people who eat these kinds of foods every day could be constantly exposing themselves, which may not only affect their health and their children’s health, but maybe even their grandchildren’s health.

Being pregnant during the Dutch famine of the mid-1940s didn’t just lead to an increase in diseases among their kids, but even apparently their grandkids. What a pregnant woman eats now may affect future generations. “The issue of generation-spanning effects of poor conditions during [pregnancy]…may shed light on the epidemic of diabetes, obesity and cardiovascular disease,” which is associated with the transition towards Western lifestyles.


Epigenetics is the science of altering the expression of our genes. No matter our family history, some genes can be effectively turned on and off by the lifestyle choices we make. See, for example:

For more on “obesogenic” chemicals, see:

I previously touched on PAHs in Meat Fumes: Dietary Secondhand Smoke.

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live, year-in-review presentations: