Chapter 166
Synergy Between Plants
Let’s look, for example, at what happens when different fractions of pomegranate polyphenols are used in vitro against prostate cancer cells. One subfraction inhibited the growth of the cancer cells by 30 percent more than a control substance; another subfraction did nothing at all—the cancer kept growing as if nothing had happened. And if you mix the two compounds together, you might assume their effect would land somewhere in between, at perhaps 15 percent growth inhibition, with the ineffective fraction diluting the better one. But that’s not what happens. Combined, they produce 70 percent less cancer growth. 30 percent + 0 percent = 70 percent. That’s synergy: 1 + 1 is greater than 2. A supplement made from pomegranate extract containing only one of the fractions would leave most or all of the effect untapped.
When different fractions from cranberries were used against colon cancer cells, the discrepancy was even greater. Considered individually, only two polyphenol fractions suppressed the growth of cancer cells by at most 15 percent, but when they were put back together into the full cranberry polyphenol complement, they suppressed colon cancer growth by up to 90 percent. Components of ginger roots, grape skins, rosemary leaves, and tomatoes showed similar synergistic effects in vitro against human cancer cells.
At see.nf/tomatosynergy you can see something amazing about synergy in action. Essentially, it boils down to the fact that dietary supplements with the red tomato pigment lycopene were unable in multiple studies to prevent or inhibit prostate cancer, but tomato sauce seemed to work. That makes sense, because studies show that tomato components that are ineffective individually—or worse—suddenly act against cancer when combined. When it comes to phytonutrients, plants are better than pills. To quote a former president of the American College of Lifestyle Medicine: “The active ingredient in broccoli is broccoli.”
Synergy Between Plants
Plants not only have thousands of different phytonutrients; they also have very different phytonutrient profiles. Therefore, synergistic effects can also occur when you eat different plants together. The reason you should eat vitamin C as citrus fruits rather than swallowing it as a tablet is that this way you don’t miss out on citrus phytonutrients like lemonin, limonol, and tangeretin, which interact, work together, and complement one another. But you miss them too if you eat an apple instead. Comparing apples and oranges is like, well, comparing apples and oranges.
At least fruit is always fruit, whereas vegetables can be any other part of a plant. Roots contain different phytonutrients than sprouts. Carrots are roots, celery is a stalk, dark leafy greens are leaves, peas are pods, and cauliflower is, as its name suggests, a bundle of flower buds. When foods from different categories are combined, synergy becomes more likely. For example, the combined antioxidant effect of raspberries and adzuki beans together is greater than the sum of each alone. Neither soy phytonutrients nor components of green or black tea alone reduced tumor burden or metastasis of human prostate cancer implants in mice, but soy and tea together did. Pepperoni extracts alone appeared to have little effect on the growth of cervical or breast cancer cells, but in a mixture with green tea, their cancer-killing effect increased tenfold for cervical cancer and one hundredfold for breast cancer compared to green tea alone.
These are interesting basic studies, but they are of limited relevance for humans if the cancer-inhibiting concentrations from the Petri dish cannot be reached in the bloodstream through normal diet. To solve this problem, researchers exposed breast cancer cells from different patients to six different plant compounds, first individually, then all together at a concentration like what can be found in the blood after eating foods such as broccoli, grapes, soybeans, and turmeric. While the individual plant compounds had little or no effect, the blood levels of all of them together suppressed the growth of breast cancer cells by more than 80 percent, inhibited migration and invasion of cancer cells, prevented the spread of cancer cells, and eventually killed them all. This “phytochemical super-cocktail” had no harmful effects on normal, non-diseased cells used as a control.
In rats whose diets consisted of 10 percent tomatoes, prostate cancer tumor burden was reduced by 33 percent; with 10 percent broccoli it fell by 42 percent. When both tomatoes and broccoli were added to the diet, tumor levels dropped by more than half. A wife wrote to the editor-in-chief of the Harvard Men’s Health Watch that her husband, after hearing about lycopene, constantly wanted to eat pizza for his prostate, but she didn’t think pizza was healthy. In response, the physician suggested “pizza without cheese (and please with broccoli instead of salami).”
Variety from the Garden
There are generic plant compounds like vitamin C that are found across the board in plants, but there are also specific phytonutrients that are produced by specific plants to fulfill specific functions—both in their organs and in ours. We miss these if we always eat the same fruits and vegetables, even if that’s many servings every day.
Civilian pilots sustain major damage to their DNA because they are bombarded with radiation from space, without the protection of the entire atmosphere. One study found that pilots who ate a wider variety of phytonutrients had less chromosomal damage, but the calculation was not adjusted for total fruit and vegetable intake. Maybe the greater variety was just a sign of larger amounts. Participants randomized to eat 14 servings of fruits and vegetables daily for two weeks had lower oxidative DNA damage than those who ate only four servings per day, but what about a study with the same number of servings, and only the variety of plant foods increased? That’s exactly what a research group in Colorado investigated.
The two diet plans contained the same number of servings per day (eight to ten), but the high plant variety included fruits and vegetables from 18 plant families, compared with low variety from only five. Only in the participants randomized to the high variety did the researchers find a significant decrease in DNA damage. They concluded that “smaller amounts of many phytochemicals have greater potential for positive effects than larger amounts of fewer phytochemicals.” Observational studies also found that fruit and vegetable variety is associated with lower inflammation and better cognitive performance—again, independent of amount. Does this kind of mix and match of plant foods actually affect patients?
At see.nf/foodcombining you’ll find a crazy experiment in which cancer patients were secretly given a combination of a fruit, a vegetable, a spice, and a leaf—per day about one hundredth of a pomegranate, less than one broccoli floret, less than one eighth teaspoon of turmeric, and the equivalent of about one sixth of a bag of green tea, hidden in capsules and compared with a placebo in a randomized trial. Surely such tiny amounts can’t affect the course of cancer, right? Wrong. As I show in the video, the cancer was significantly slowed.
According to the updated version of the most comprehensive study ever published on diet and cancer, the foundation of cancer prevention is a plant-based diet—whole grains, vegetables, fruits, and beans—and avoiding alcohol, sodas, meat, and industrial junk. In How Not to Die, I document that a strictly plant-based diet can not only slow a tumor’s growth, but can even make it shrink, but there is no reason why we shouldn’t be able to achieve both with a diet full of powerful plants.