The Paleolithic period, also known as the Stone Age, only goes back about two million years. Humans and other great apes have been evolving for the last 20 million years, starting back in the Miocene era. We hear a lot about the paleolithic diet, but that only represents the last 10 percent of hominoid evolution. What about the first 90 percent?

During the Miocene era, the diet “is generally agreed to have been a high-fiber plant-based diet…” For the vast majority of our family’s evolution, we ate what the rest of our great ape cousins eat—leaves, stems, and shoots (in other words, vegetables), as well as fruits, seeds, and nuts. I explore this in my video Lose Two Pounds in One Sitting: Taking the Mioscenic Route.

“Anatomically, the digestive tracts of humans and great apes are very similar.” In fact, our DNA is very similar. So, what do our fellow great apes eat? Largely vegetarian diets with high greens and fruit consumption. Just largely vegetarian? It’s true that chimpanzees have been known to hunt, kill, and eat prey, but chimpanzees’ “intake of food of animal origin is still at a very low level…with only 1.7% of chimpanzee feces providing evidence of animal food consumption.” This is based on eight years of work collecting nearly 2,000 fecal samples. So, even the most carnivorous of great apes appears to eat about a 98 percent plant-based diet. In fact, we may be closest to the diet of bonobos, one of the less known great apes, who eat nearly exclusively plant-based diets, as well.

Even our Paleolithic hunter-gatherer ancestors must have done an awful lot of gathering to get the upwards of 100 grams of fiber a day they may have consumed. What would happen if researchers put people on an actual Paleolithic diet? Not a supermarket-checkout-aisle-magazine paleo diet or some caveman blogger diet, but an actual 100-grams-of-daily-fiber diet or, even better, a mioscenic diet, taking into account the last 20 million years of evolution since we split with our common great ape ancestors.

Dr. David Jenkins and colleagues gave it a try and “tested the effects of feeding a diet very high in fiber.” How high? We’re talking 150 grams of daily fiber, far higher than the recommended 20 to 30 grams a day. However, 150 grams is similar to what populations in rural Africa used to eat—populations almost entirely free from many of our chronic killer diseases, such as colon cancer and heart disease.

The high-fiber diet didn’t mess around. Lunch, for example, could include Brussels sprouts, okra, green peas, mushrooms, filberts, and a plum. And dinner? How about asparagus, broccoli, eggplant, carrots, and honeydew melon? Surely, simply eating a lot of fruits, veggies, and nuts can’t be very satisfying, right? Actually, it got the maximum satiety rating from every one of the ten subjects, unlike the starch-based and low-fat diets which scored lower. Why? “All of the diets were designed to be weight-maintaining,” meaning the researchers didn’t want weight loss to confound the data. So, to get a full day’s calories of whole plant foods, the subjects had to eat about 11 pounds of food a day! Not surprisingly, this resulted in some of the largest bowel movements ever recorded in the medical literature, with men on the high-fiber vegetable-based diet exceeding a kilogram of fecal weight per day. You know how some people on weight loss diets lose two pounds a week? Well, in this study, the subjects dropped two pounds in one sitting.

That wasn’t the only record-breaking drop: A 33 percent drop in LDL cholesterol within just two weeks was seen. Even without any weight loss, bad cholesterol levels dropped by one-third within two weeks. That’s one of the biggest drops I’ve ever seen in any dietary intervention—better than achieved on a starch-based vegetarian diet or a low saturated fat American Heart Association-type vegetarian diet. This was a “cholesterol reduction equivalent to a therapeutic dose of a statin” drug. So, we need to take a drug to get our cholesterol levels down to where they would be normally were we to eat a more natural diet.

We’ve been eating 100 grams of fiber every day for millions of years. This diet is similar to what’s eaten by populations who don’t suffer from many of our chronic diseases. Maybe this shouldn’t be called a “very high fiber” diet. Maybe what we eat today should be considered a very low, extremely fiber-deficient diet.

Maybe it’s normal to eat 100 grams of fiber a day. Maybe it’s normal to be free of heart disease. Maybe it’s normal to be free of constipation, hemorrhoids, diverticulitis, appendicitis, colon cancer, obesity, type 2 diabetes, and all other the diseases of Western civilization.

How do we know our ancient ancestors ate more than 100 grams of fiber a day? We can examine their fossilized fecal matter, as I discuss in my video Paleopoo: What We Can Learn from Fossilized Feces.

For more evidence on what our natural diet is, see my What’s the Natural Human Diet? video.

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Excited to share what you’ve learned about diet? Well, it turns out you can share more than my videos. Check out How to Become a Fecal Transplant Super Donor.

In health,

Michael Greger, M.D.