Cancer-Proofing Your Body

Lifestyle medicine pioneer Nathan Pritikin was an unlikely candidate to spark a nutrition revolution. He wasn’t a doctor or dietician but an engineer. As featured in my 2-min. video Engineering a Cure, he reversed his own heart disease with a plant-based diet and went on to help millions of others. He even saved the life of my own grandmother, which is what inspired me to go into medicine.

Pritikin’s work has continued though his research foundation. Once Dean Ornish proved that Our Number One Killer Can Be Stopped, the focus shifted from heart disease to cancer. In the video I feature above, I describe an elegant series of experiments in which people were placed on different diets and their blood was then dripped on cancer cells in a petri dish to see which diet was more effective at suppressing cancer growth.

As you can see, even the blood of those on a standard American diet (SAD) fights cancer, but the blood of those on vegan diets fights about 8 times better. The blood circulating within the bodies of vegans appears to have nearly 8 times the stopping power when it comes to cancer cell growth. That was after maintaining a plant-based diet for a year though. Subsequent studies against breast cancer showed the power of eating plants for just two weeks. Watch the video above to see the remarkable results.

This dramatic strengthening of cancer defenses was after 14 days of a plant-based diet and exercise—they were out walking 30 to 60 minutes a day. Although Pritikin started out reversing chronic disease through diet alone, later—to his credit—he added an exercise component as well. That’s great for the patients, but scientifically it makes it hard to tease out which intervention is doing what. Maybe the only reason their blood started becoming so effective at suppressing cancer growth was because of the exercise—maybe the diet component had nothing to do with it. This had to be put to the test.

In my 4-min. video Is It the Diet, the Exercise, or Both? I describe the experiment. Three groups were compared: a plant-based diet and exercise group, an exercise only group, and a control group that did neither. The diet and exercise group had been on a plant-based diet for 14 years along with moderate exercise as simple as walking every day. The second group was exercise and hardcore exercise at that: 14 years of daily, strenuous, hour-long exercise like calisthenics, but they ate the standard American diet. Which group was better at fighting cancer?

The researchers took petri dishes brimming full of human prostate cancer cells and dripped blood from each of the three groups on different dishes to see whose blood kicked more cancer butt. Watch the diet vs. exercise video to see actual photomicrographs of the effects on cancer cells. Basically they found that strenuous exercise worked, but good diet with just moderate exercise worked better.

Even though diet appears more powerful than exercise in terms of rallying one’s cancer defenses it doesn’t mean we can’t do both! In fact eating certain plants can improve athletic performance—check out my video series that starts with Doping With Beet Juice and ends with So Should We Drink Beet Juice Or Not?.

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my videos for free by clicking here and watch my full 2012 presentation Uprooting the Leading Causes of Death.

Image credit: Dr. Raowf Guirguis / National Cancer Institute / Wikimedia Commons

Poultry and Penile Cancer
Coffee and Cancer
Breast Cancer Survival and Soy


Daniela M
Daniela M9 months ago

Thank you for this.

W. C
W. Cabout a year ago

Thank you.

William C
William Cabout a year ago


Jeanne Rogers
Jeanne Rabout a year ago

Thank you for sharing.

Past Member 2 years ago

wow, indeed. As cancer runs in my family, this is interesting. Mother, father, both grandfathers, uncle, great aunt. That's a high percentage considering my mother had only one sibling, and my father had none.

Sarah M.
Sarah M5 years ago


Santa W.
Santa W.5 years ago

Access to health care varies across countries, groups and individuals, largely influenced by social and economic conditions as well as the health policies in place. Countries and jurisdictions have different policies and plans in relation to the personal and population based health care goals within their societies. Thanks.

Santa W.
Lafjohn Wify5 years ago

Although often detected early in the United States due to the regular gynecological care, it still pays to be familiar with the symptoms, which include vaginal bleeding, localized pain in the pelvis, vaginal discharge, or pain throughout intercourse. Where cervical cancer is found, you have a number of treatment options to consider depending on the particulars of your cancer. Thanks.

Ellen F.
Ellen G5 years ago

Great information. But... CAN'T stand the voice-over guy's delivery. Don't act, just read. Don't add "Uh.." and "Um" like you're sharing your knowledge and thinking about what you're telling us off the top of your head. You're not. You are reading the copy off a paper! So just read and tell us the information! Thank you! (Sorry for the rant. I've heard this guy before and I find it takes away from what we're supposed to be learning).

Ajla C.
Past Member 5 years ago