“Three foods to avoid at all costs.” “Forget protein: here’s how to build muscle over 60.” “The secret health foods to eat that they don’t want you to know about.” We are seeing ads like this all over the Internet. You see them and know that they are hawking for some food supplement, membership program, or other shortcut to health — they really are looking for your money, but you can’t resist clicking on them because, maybe this time, you’ll get a tip to really fix up your health.
If you want to know what people really care about, look at ads. Agencies spend lots of money figuring out what are the hot topics that will draw in the most people. Judging from the prevalent health ads, it’s obvious that many of us are concerned about our health, and suspect that some food or nutritional supplements could hold the key. We will put aside our skepticism yet again and click on the ad because we desperately want there to be a magic bullet, an answer to fix our health.
The message that “food is medicine” has penetrated to the public at large. But along with that message is another one: nature’s food is insufficient and you must concentrate or supplement certain aspects of food to get everything you need to supercharge your health. You can’t do that without the help of some laboratory that can take fruits and vegetables or some nutrient-laden food and distill just the stuff you need. Then you’ll feel better, have more energy, and so long as you take the supplements, you can eat whatever else you want because the supplement gives you the key to health and longevity.
Yes, some supplements might be helpful. Your diet is likely deficient in some nutrients if you are eating a typical American diet. The advertisement may even bring out some legitimate, science-based data and accurately describe your symptoms. If you suffer from low energy, undesired weight gain, mood swings, trouble sleeping, high cholesterol, bone loss, headaches, trouble concentrating, bloating, gas, acid reflux, hemorrhoids (did we miss a symptom? Add it here…) then they tell you their product will help. Well, here’s the real answer, and you won’t have to buy a supplement to get it. Are you ready?
Do this one thing to fix your health…
The one thing is: regularly eat the way your body is designed for you to eat. You can add supplements if you’d like, and they may even work better because you have set your internal environment to better absorb nutrients which the supplements contain. If you don’t eat properly, even the best supplement will disappoint you. Simple — that’s it. So there’s no need for you to read further – unless you would like to know more about how your body is designed to handle food and you would like some help eating ideally for your health.
Designer Genes
How were we designed to eat? Well, it definitely is not the way most of us eat today. Processed food, chemical additives, unnatural levels of sugar, high levels of meat and dairy, and the sterilized avoidance of the microbes that normally come along with food in nature are the modern diet — even specialized popular diets often don’t address these factors. Genetically, we have not changed much from our ancestors, who didn’t have the modern conveniences that allow food to store for long periods and even sit on store shelves for weeks or months before purchase. If we are genetically roughly the same as ancestors ten or more generations back, then why should we expect to eat differently and not have consequences?
What our modern technology has done for us is to uncover much of what is going on in our bodies. As far back as the 17th century, with the invention of the microscope, scientists discovered that there were some sort of cells running around in the intestines of people and animals. We now know that the “microbiota”, the colonies of the bacteria and other microbes that exist in our digestive tracts but are not “us”, have more cells than our bodies contain. They are in many ways rulers of our digestion. They are often likened to a forest, which contains many different sorts of trees, underbrush, grasses, ground plants of all sorts, and even bugs that fly around helping the plants to survive. Our microbiota, or gut flora, are highly diverse like a forest once they are fully established. And like a forest responds to its environment – weather conditions, seasons, existing neighboring plants in the forest, invasions of disease or predatory insects, and available soil nutrients — your microbiota responds greatly to the conditions in your gut.
Fire away
What happens to the forest after a forest fire? Most of the trees and plants have been burned up. Roots and seeds may be all that is left because they are underground. The forest has to regrow, and it will take some time and favorable conditions. Our guts have probably faced a few “forest fires” in our lifetimes because we were given rounds of antibiotics to deal with a bad infection or upcoming medical procedure. But the microbiota forest can also experience a slow burn, where we constantly feed it toxic, sugar-laden, low fiber diets that promote the aggressive bad bacteria over the most health-promoting bacteria. Then we wind up with an ugly forest full of the bacterial versions of brambles, sickly trees with few varieties, and overrun with pests. In many ways, the forest full of brambles and pests is worse than a forest cleared out by a fire, because the bad but established plants resist the growth of good trees. The condition of the gut flora of many of us is that of weeds — aggressive bacteria that want to dominate the gut and prevent a take over by good bacteria.
Those aggressive bacteria are not just unwanted weeds, they cause actual damage. Rather than helping with digestion and producing beneficial byproducts, they produce toxins and inflammatory chemicals. These irritate the thin and delicate semi-permeable intestinal linings, which develop gaps that allow toxins to pass through into the blood. We call this “leaky gut.” The toxins poison your whole body so your immune system must mop them up as best it can. Some toxins even make it past the blood-brain barrier, which is a condition we call “leaky brain.” Simple sugars and carbohydrates are great food for bad bacteria, and in the presence of sugar, they multiply extremely rapidly.
A proper gut flora would contain bacteria that partially digest food, leaving byproducts which, rather than being toxins, are useful and more easily digested byproducts. This doubles the importance of good microbiota that not only don’t do damage, but allow you to absorb vital food micronutrients. Short-chain fatty acids (SCFAs), some B vitamins, and vitamin K will be largely unavailable without good microbiota. Proteins and fat breakdown are both aided by good bacteria.
Fiber is key
You’ve probably heard “eat more fiber.” Fiber, the undigestible portion of plants which is non-existent in animal products, is digestible to the good gut bacteria and is a vital food source for them. You don’t need to eat more fiber just to help your intestines push food along and keep it traveling through your system — it is very important for that — but also to feed good gut flora. Plus you get nutrients from the breakdown of the fiber that are otherwise unavailable to you. So these are three good reasons to eat more fiber.
Now you start to see how we were designed to eat. Gut flora is part of our design: even though it is not part of us, it resides in us and we need it to be healthy. Part of our diet must be geared to its benefit so we can get benefit from it. Even though we can eat animal products — our digestion is amazingly adaptable — they are devoid of fiber. Animal products also acidify the body, carry toxins that were concentrated by the animal’s body, and are not nearly as rich in micronutrients as plants. Even though we are technically omnivores, we do best when we are mostly vegetarian.
Plants are our complimentary partners in nature. We need oxygen and give off carbon dioxide. Plants use carbon dioxide and give off oxygen. Plants contain all the nutrients we need if we combine leafy greens with plant fats (especially avocados), seeds, nuts, and low sugar fruits. We were designed to function best on plants, preferably while those plants are themselves still living.
Science backs this up. We know much more than ever before about gut flora — how it should be very diverse (a robust colony of many different varieties of microbes), how it can strengthen our immune system or tear it down, how modern drugs negatively affect it, and how to regrow it to a healthy state. Published in Nature is an animal study where researchers at The University of Chicago manipulated the diet of animals after they had been given antibiotic treatments to learn how best to rebuild their gut flora (1). They went so far as to take microbes from healthy animals with good microbiota and transplant them into the animals that had undergone antibiotic treatments. That theoretically would have restored the digestion of those animals to normal because they had been given the microbes that they needed. However, until the animals ate a plant-based diet that was high in fiber, the transplants failed work. Only when their diet mimicked the so-called Mediterranean Diet (MED) did the transplanted gut microbes “take” and establish residency in the animals’ intestines, then they were able to show positive health impacts. When their diet was more like the typical “Western” diet, the transplants died quickly and the bad bacteria grew and dominated. After antibiotics wiped out most of the gut flora, leaving behind the most dangerous, drug-resistant, and hardy bacteria, the researchers needed to “regrow the forest” to restore the animals to health. Sugar, meat, dairy products, and highly processed foods were listed as the most damaging to gut flora.
Sometimes more of a good thing isn’t so good. In diet, however, more green is better. The Nature study copied from the Mediterranean Diet (MED) to heal the gut flora quickly in the study. MED is widely considered to be the best, most healthful diet available. However, there is a lesser-known Green Mediterranean Diet (Green-MED) which further reduces consumption of meat and dairy, replacing them with high polyphenol plant foods. There are over 8,000 different types of polyphenols, including flavonoids, which are particularly protective against free radicals (which are particularly abundant in meat and any cooked food). This substitution super-charges the MED diet. This too has been researched: thanks to the popularity of the Mediterranean Diet, scientists want to know if that diet could be improved further. Published in Genome Medicine is a human trial conducted by researchers from the University of Minnesota, Harvard Medical School, and Tel-Aviv University where they tested a standard diet, the MED diet, and the Green-MED diet with three groups of participants (2). While both the MED and Green-MED diets improved gut flora, the Green-MED diet led to greater flora diversity and improved branched-chain amino acid management. Simply put, the Green-MED was more robust and effective in developing beneficial gut flora colonies than even the MED diet.
Ad this
If you find yourself even slightly drawn to the claims of health food advertisers, then how can you not jump onto the Green-MED bandwagon, especially when research clearly shows the importance of good gut flora and the value of raw, fresh greens, nuts, seeds and plant fats? You get all the micronutrients along with vital fiber that plants have to offer. Then you build up your microbiota, which will help you break down your food even better. Plant diets create a healthy upward health spiral which gives you more nutrients while reducing toxins. If you find the high fiber plant diet seems to give you digestive problems, that just means your gut flora are still adjusting to the new environment — it takes time to regrow the forest properly.
Dr. Nemec’s Review
Let’s go over these studies in a little more detail. In the Nature study, the key point was that eating the fiber from natural foods is far superior than even the best medicine can offer, which is a stool transplant from a healthy animal with a good microbiome. The study showed even if you put the beneficial bacteria in with a stool implant, it didn’t work because the bacteria was meant to come from the breakdown of fiber from plants, not from foreign fecal implants.
The answer is obvious: just eat more green plants — a lot more. Food really is your medicine, but we’re always looking for a shortcut, a quick fix, an easier way than just eating the food we were designed to eat from the beginning.
The next study in Genome Medicine compared three diets: the diet considered to be the best by much of the world, the Mediterranean diet; a special version of the Mediterranean diet, which substitutes more green plants and vegetables; and then the third diet was a healthy Western diet.
Here are the results:
The Green Mediterranean diet was the clear winner because it had the best:
- Lipid profile
- Glycemic control
- Visceral fat loss
- Gut microbiome composition
- Weight reduction
- Inflammation reduction
The most important factor was that the Green Mediterranean diet was almost twice as anti-inflammatory as the Mediterranean diet and almost 4 times as anti-inflammatory as the healthy Western diet.
Inflammation is the root of disease, so anything that puts out the fire is going to benefit you tremendously — now and in the future. So by far the healthiest thing to put in your intestinal tract to grow the beneficial microbiome bacteria are green leafy vegetables, because they mainly provide insoluble and soluble fiber and polyphenols. Right after that, garlic and onions in the raw state (not cooked), because they are rich in other prebiotic fibers, particularly inulin and fructooligosaccharides (FOS), which also feed beneficial gut bacteria.
Why is a plant-based diet so powerful? Why are green leafy vegetables so powerful? They were the diet of design from the beginning.
There’s so many aspects we could talk about with a green plant-based diet, but we will cover just one area mentioned in the Genome Medicine article on the superior diet of the Green Mediterranean version. Green plants and plants in general have polyphenols. These are plant chemicals to protect them and to keep them healthy. Here are just some of the benefits of the polyphenols:
- Antioxidant protection, which neutralize free radicals that damage cells and the DNA genetic structure. They also protect LDL cholesterol from oxidation. And they slow down age-related oxidative stress.
- Anti-inflammatory effects inhibit inflammatory cytokines and lower inflammation that develops in the arteries and the tissues
- Cardiovascular effects improve endothelial function — the lining inside the blood vessels, lower blood pressure, reduce insulin resistance, and regulate proper lipid balance.
- Neuroprotective — protecting neurons from oxidative stress. These polyphenols cross the blood brain barrier and are linked to lower risk of cognitive decline.
- Cancer protective: polyphenols reduce DNA damage. They inhibit tumor-promoting substances and they also induce apoptosis in abnormal cells.
Which leafy greens are best?
All of them — just eat as many as you can. Some of the big ones are:
- Spinach — containing the flavonoids quercetin and kaempferol along with phenolic acids.
- Kale — which contains flavonoids quercetin and caffeic acid.
- Romaine lettuce — which contains chicoric acid, quercetin and luteolin.
- Arugula — which contains hydroxycinnamic acids
And as Hippocrates, the father of medicine said: “in food excellent medicine can be found.”
(1) Kennedy MS, Freiburger A, Cooper M, Beilsmith K, St George ML, Kalski M, Cham C, Guzzetta A, Ng SC, Chan FK, DeLeon O, Rubin D, Henry CS, Bergelson J, Chang EB. Diet outperforms microbial transplant to drive microbiome recovery in mice. Nature. 2025 Jun;642(8068):747-755. doi: 10.1038/s41586-025-08937-9. Epub 2025 Apr 30. PMID: 40307551. https://pubmed.ncbi.nlm.nih.gov/40307551/
(2) Rinott E, Meir AY, Tsaban G, Zelicha H, Kaplan A, Knights D, Tuohy K, Scholz MU, Koren O, Stampfer MJ, Wang DD, Shai I, Youngster I. The effects of the Green-Mediterranean diet on cardiometabolic health are linked to gut microbiome modifications: a randomized controlled trial. Genome Med. 2022 Mar 10;14(1):29. doi: 10.1186/s13073-022-01015-z. PMID: 35264213; PMCID: PMC8908597. https://pmc.ncbi.nlm.nih.gov/articles/PMC8908597/
