How to Achieve Food Synergy

There are thousands of phytochemicals that will never make it onto the side of a cereal box but may play a role in reducing the risk of chronic diseases—and those are just the ones we know about. Whole plant foods have consistently been found to be protective, so it’s reasonable for scientists to try to find the “magic bullet” active ingredient that can be sold in a pill, but “[p]ills or tablets simply cannot mimic this balanced natural combination of phytochemicals present in fruits and vegetables.” When isolated out, the compound may lose its activity or behave differently. The antioxidant and anticancer activities of plant foods are thought to derive from the “additive and synergistic effects of phytochemicals in fruits and vegetables,” meaning the whole may be greater than the sum of its parts. This helps explain why a pill can’t replace the complex combination of phytochemicals present in whole plant foods.

As T. Colin Campbell has pointed out, more than a hundred trials “overwhelmingly show no long-term benefit for vitamin supplements, along with worrisome findings that certain vitamins may even increase disease occurrence for diabetes, heart disease, and cancer.” Supplementation with fish oil, for example, appears useless or, even worse, “posing increased risk for diabetes,” yet the science doesn’t seem to matter. People continue to buy them. “The public desire for quick fixes through pills…is overwhelming, especially when money can be made.”

Each plant has thousands of different phytochemicals, as well as entirely different phytonutrient profiles. So, there may be synergistic effects when eating different foods together, too. Eating beta-carotene in carrot form is more beneficial than in pill form. because of all the other compounds in the carrot that may synergize with the beta-carotene. Well, when we dip that carrot in hummus, we suddenly have the thousands of carrot compounds mixing with the thousands of chickpea compounds. So what happens if we mix different fruits with different vegetables or different beans?

As you can see in my video Food Synergy, combining foods across different categories increased the likelihood of synergy. For example, a study showed the antioxidant powers of raspberries and adzuki beans. If there were a strictly additive effect, the expected combined antioxidant power would simply be that of the raspberries plus that of the adzuki beans. However, the observed combined antioxidant power was actually greater than the sum of one plus the other.

What about cancer-fighting effects? The study was repeated, but, this time, different combinations of food were dripped on breast cancer cells growing in a petri dish. For some foods, the same synergistic effects were found. Grapes, for example, can suppress the growth of breast cancer cells about 30 percent, but onions worked even better, cutting breast cancer cell growth in half. One would assume that if we added half the grapes with half the onion, we’d get a result somewhere in the middle between the two. Instead, the researchers found that cancer cell growth was suppressed by up to 70 percent with that combination. The whole plus the whole was greater than the sum of the whole parts. Given these findings, did the researchers recommend people eat a variety of foods? Perhaps adding some raisins along with chopped red onions to our next salad? Where’s the money in that? No, the reason the researchers were investigating the different types of interactions was “to identify mixtures that hold synergistic interactions that can ultimately lead to the development of functional foods”—maybe something like grape-flavored Funyuns.


Why should we care about the antioxidant power of foods? See

If you’re not familiar with this concept of reductionism, be sure to check out some of these other videos: Industry Response to Plants Not Pills, Why Is Nutrition So Commercialized?, and Reductionism and the Deficiency Mentality.

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:

What’s the Secret to Latino Longevity?

Latinos living in the United States tend to have “less education, a higher poverty rate, and worse access to health care” and “represent the ultimate paradigm of healthcare disparities,” with the highest rate of uninsured, lowest rates of health screening and counseling, and poorest levels of blood pressure and blood sugar control, as well as “other measures of deficient quality of care.” So they must have dismal public health statistics, right? According to the latest national data, the life expectancy of white men and women is 76 and 81 years, respectively, and that of black men and women is shorter by a handful of years. And Latinos? Amazingly, they beat out everyone.

Latinos live the longest.

This has been called the Hispanic Paradox (now also known as the Latino Paradox), which I explore in my video, The Hispanic Paradox: Why Do Latinos Live Longer?. Latinos have a 24 percent lower risk of premature death and “lower risks of nine of the leading 15 causes of death,” with notably less cancer and heart disease. This was first noticed 30 years ago but was understandably was met with great criticism. Maybe the data were unreliable? No, that didn’t seem to be it. Maybe only the healthiest people migrate? Turns out the opposite may be true. What about the “salmon bias” theory, which “proposes that Latinos return to their home country…to ‘die in their home’” so they aren’t counted in U.S. death statistics? That theory didn’t pan out either.

Systematic reviews “confirm the existence of a Hispanic Paradox.” Given the strong evidence, it may be time to accept it and move on to figuring out the cause. The very existence of the “Hispanic Paradox” could represent “a major opportunity to identify a protective factor for CVD [cardiovascular disease] applicable to the rest of the population.” After all, whatever is going on “is strong enough to overcome the disadvantageous effect” of poverty, language barriers, and low levels of education, health literacy, quality of healthcare, and insurance coverage. Before we get our hopes up too much, though, could it just be genetic? No. As foreign-born Latinos acculturate to the United States, as they embrace the American way of life, their mortality rates go up. So, what positive health behaviors may account for Latino longevity?

Perhaps they exercise more? No, Latinos appear to be even more sedentary. They do smoke less, however the paradox persists even after taking that into account. Could it be their diet? As they acculturate, they start eating more processed and animal-based foods, and consume fewer plant foods—and perhaps one plant food in particular: beans. Maybe a reason Latinos live longer is because they eat more beans. Although Latinos only represent about 10 percent of the population, they eat a third of the beans in the United States, individually eating four to five times more beans per capita, a few pounds a month as opposed to a few pounds per year. That may help explain the “Hispanic Paradox,” because legumes (beans, split peas, chickpeas, and lentils) cool down systemic inflammation.

In my video, you can see the mechanism researchers propose in terms of lung health. While cigarette smoking and air pollution cause lung inflammation, which increases the risk for emphysema and lung cancer, when we eat beans, the good bacteria in our gut take the fiber and resistant starch, and form small chain fatty acids that are absorbed back into our system and decrease systemic inflammation, which not only may inhibit lung cancer development, but also other cancers throughout the body. Latinos have the lowest rates of chronic obstructive pulmonary disease (COPD) and lung cancer, and also tend to have lower rates of bladder cancer, throat cancer, and colorectal cancer for both men and women.

This “systemic inflammation” concept is also supported by the fact that when Latinos do get cardiovascular disease or lung, colon, or breast cancer, they have improved survival rates. Decreasing whole body inflammation may be important for both prevention and survival.

Asian Americans also appear to have some protection, which may be because they eat more beans, too, particularly in the form of tofu and other soy foods, as soy intake is associated with both preventing lung cancer and surviving it.

Hispanics also eat more corn, tomatoes, and chili peppers. A quarter of the diet in Mexico is made up of corn tortillas, and Mexican-Americans, whether born in Mexico or the United States, continue to eat more than the general population. Looking at cancer rates around the world, not only was bean consumption associated with less colon, breast, and prostate cancer, but consumption of rice and corn appeared protectively correlated, too.

Since NAFTA, though, the North American Free Trade Agreement, the Mexican diet has changed to incorporate more soda and processed and animal foods, and their obesity rates are fast catching up to those in the United States.

In the United States, Latinos eat more fruits and vegetables than other groups, about six or seven servings a day, but still don’t even make the recommended minimum of nine daily servings, so their diet could stand some improvement. Yes, Hispanics may only have half the odds of dying from heart disease, but it’s “still the number one cause of death among Hispanics. Therefore, the current results should not be misinterpreted to mean that CVD is rare among Hispanics.” Ideally they’d be eating even more whole plant foods, but one thing everyone can learn from the Latino experience is that a shift toward a more plant-based diet in general can be a potent tool in the treatment and prevention of chronic disease.


Data like this support my Daily Dozen recommendation for eating legumes ideally at every meal, and we have free apps for both iPhone and Android that can help you meet these dietary goals.

For more on the wonders of beans, split peas, chickpeas, and lentils, see my videos and love your legumes!:

What’s the best way to eat them? See Canned Beans or Cooked Beans? and Cooked Beans or Sprouted Beans?.

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:

What to Feed Your Gut Bacteria

For many years, it was believed that the main function of the large intestine was just to absorb water and dispose of waste, but “[n]owadays it is clear that the complex microbial ecosystem in our intestines should be considered as a separate organ within the body,” and that organ runs on a MAC, microbiota-accessible carbohydrates. In other words, primarily fiber.

One reason we can get an increase of nearly two grams of stool for every one gram of fiber is that the fiber fermentation process in our colon promotes bacterial growth. The bulk of our stool by weight is pure bacteria, trillions and trillions of bacteria, and that was on a wimpy, fiber-deficient British diet. People who take fiber supplements know that a few spoonfuls of fiber can lead to a massive bowel movement, because fiber is what our good gut bacteria thrive on. When we eat a whole plant food like fruit, we’re telling our gut flora to be fruitful and multiply.

From fiber, our gut flora produce short-chain fatty acids, which are an important energy-source for the cells lining our colon. So, we feed our flora with fiber and then they turn around and feed us right back. These short-chain fatty acids also function to suppress inflammation and cancer, which is why we think eating fiber may be so good for us. When we don’t eat enough whole plant foods, though, we are in effect starving our microbial selves, as I discuss in my video Gut Dysbiosis: Starving Our Microbial Self. On traditional plant-based diets, we get lots of fiber and lots of short-chain fatty acids, and enjoy lots of protection from Western diseases like colon cancer. In contrast, on a standard American diet filled with highly processed food, there’s nothing left over for our gut flora. It’s all absorbed in our small intestine before it even makes it down to the colon. Not only may this mean loss of beneficial microbial metabolites, but also a loss in the beneficial microbes themselves.

Research shows the biggest issue presented by a Western diet is that not leaving anything for our bacteria to eat results in dysbiosis, an imbalance wherein bad bacteria can take over and increase our susceptibility to inflammatory diseases or colon cancer, or maybe even lead to metabolic syndrome, type 2 diabetes, or cardiovascular disease.

It’s like when astronauts return from space flights having lost most of their good bacteria because they’ve had no access to real food. Too many of us are leading an “astronaut-type lifestyle,” not eating fresh fruits and vegetables. For example, the astronauts lost nearly 100 percent of their lactobacillus plantarum, which is one of the good guys, but studies reveal most Americans don’t have any to begin with, though those who eat more plant-based are doing better.

So it’s use it or lose it. If people are fed resistant starch, a type of MAC found in beans, within days the bacteria that eat resistant starch shoot up and then die back off when you stop. Eating just a half can of chickpeas every day may “modulate the intestinal microbial composition to promote intestinal health” by increasing potentially good bacteria and decreasing pathogenic and putrefactive bacteria. Unfortunately, most Americans don’t eat beans every day or enough whole grains, enough fruits, or enough vegetables. So, the gut flora—the gut microbiota—of a seemingly healthy person may not be equivalent to a healthy gut flora. It’s possible that the Western microbiota is actually dysbiotic in the first place just because we’re eating such fiber-deficient diets compared to populations that may eat five times more fiber and end up with about 50 times less colon cancer.


This is one of the reasons I recommend three daily servings of legumes (beans, split peas, chickpeas, and lentils) in my Daily Dozen checklist.

The microbiome connection may explain the extraordinary results in the study I featured in my video Is It Worth Switching from White Rice to Brown?.

More on the musical fruit:

More on the microbiome revolution in medicine:

For more on bowel health, check out:

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: