The transition between hunting-gathering and farming took place over a period of about 1000 years between 11000 and 10000 years ago in the Fertile Crescent, a crescent-like shape of land that stretches across parts of Israel, Lebanon, Jordan, Syria, Iran and Iraq. The first people to settle were hunter-gatherers that built villages in places they found provided enough food to sustain them without having to move around. At first, these were “seasonal” villages located in different areas, to which they returned in a seasonal cycle. Finding ways to store the grain from the large seeded grasses like barley and emmer wheat growing wild but in large quantities, allowed them to settle permanently. This most likely led to a rapid growth of the population, that was matched with a proportionally rapid growth in the demand for food. The response was the development of agriculture.

The gradual decimation of the wild game over the course of about 2000 years led to the domestication of the most easily domesticable, large mammals to inhabit the region, the sheep, goat and pig, all about 8000 years ago, followed by the cow about 6000 years ago. It is very interesting and important to point out, from an anthropological point of view, that the Fertile Crescent—the seat of civilisation—is the region in the world where there were the greatest number of large-seeded grasses, as well as the greatest number of large, easily domesticable animals, by far.

The cultivation of cereal crops allowed our ancestors, some 10000 years ago, to have, for the first time in our evolutionary history, enough spare time to develop tools and technologies, as well as arts and music. For the first time in evolutionary history, a handful of people could sow, tend to, and harvest enough cereal grain to feed hundreds or even thousands of people who were, therefore, free to do a multitude of other things. Without agriculture and this shift from the hunter-gatherer lifestyle of spending most of our waking hours hunting and rummaging around looking for food, we would not have developed much of anything because we simply never would have had the time to do so.

Now, although it is well known to most anthropologists, it is not a well appreciated fact that the cultivation and eating of cereal crops as an important source of calories, is possibly the most negatively impacting evolutionary mistake to have been made in regards to the health and robustness of our species as a whole. There was, indeed, plenty of free time, and we did develop technologies extremely quickly considering how slowly things had changed before then. But the price to pay was high.

Within as little as one or two generations, our powerful stature shrank markedly, our strong teeth rotted, our massive bones became thin and brittle, our thick hair grew thin and fell out at an early age. In fact, evidence indicates that while our hunter-gatherer ancestors were tall, strong, robust, with hard teeth and bones, and apparently healthy to their death—usually of a violent nature instead of progressive degradation through “ageing” as later became the norm, our oldest cereal-eating ancestors in contrast, were the exact opposite: small, weak, fragile, with rotten teeth, and advanced osteoporosis in their bones at the time of their death in their early 50’s. (For a lot more details about all the points discussed up to here, I strongly recommend Jared Diamond’s fascinating books: The Third Chimpanzee; Guns, Germs and Steel; and Collapse).

Today, at the beginning of the 21st century some 10000 years later, we know exactly why we were never meant to consume carbohydrates on a regular basis, let alone in large quantities as we do today, such that they provide a significant part of our daily calories—sometimes even the majority! We know exactly why because we have pretty clearly understood the primary effect of phytic acids or phytates, the importance of dietary fats, and the insulin mechanism.

Phytates are compounds that exist in all grains and legumes—where they are found in the greatest concentration—as well as in all nuts and seeds. Some animals like rats, for example, have evolved the necessary digestive mechanisms to break down phytates, but humans have not. The consequence is these bind to minerals in the gut and in so doing prevent their absorption into the bloodstream. The regular consumption of grains and legumes—and we believe that many of our first agrarian ancestors lived almost exclusively from grains—leads to severe mineral deficiencies that result in demineralisation of the teeth and bones, exactly as is seen in the remains of these ancestors.

Moreover, any diet consisting primarily of grains (and legumes) as was theirs, will also inevitably be extremely deficient in fat, that is now know to be essential for the proper function of every cell, tissue and organ in the body (especially the brain), but also crucial in the absorption of minerals. So, the combination of a high concentration of phytates together with an almost complete absence of fat, made for an extremely effective demineralisation, which is indeed seen in the smaller statures, weakened bones and teeth, and considerably shortened lifespan of our agrarian ancestors. This obviously still applies today: the more phytates, the faster the demineralisation; and the less fat; the faster the demineralisation.

Finally, insulin is a hormone secreted by the pancreas. There is always a certain concentration of glucose in the blood, and there is also always a certain concentration of insulin. If there isn’t a major metabolic disorder, then the higher the glucose concentration, the higher the insulin concentration. And conversely, the lower the glucose concentration, the lower the insulin concentration. But since the body is programmed to always keep glucose concentrations to a minimum, as soon as there is a simple carbohydrate in our mouth, insulin is secreted into the bloodstream. As the glucose—either from the simple carbohydrates or from the breakdown of starches—enters the bloodstream through the intestinal wall, and as its concentration continues to rise, the pancreas continues to secrete insulin to match the concentration of glucose; but always a little more, just to be on the safe side.

Why? If glucose were good for us, then why should we have this highly sensitive mechanism to always try to get rid of it?

Insulin’s primary role is storage of “excess” nutrients, and regulation of fat storage and fat burning: when insulin is high, there is fat storage; when insulin is low, there is fat burning. It’s very simple. This, in turn, means that insulin is the primary regulator of energy balance, and therefore of metabolism. From an evolutionary perspective, the importance of insulin is perfectly clear. Firstly, it is a mechanism that is common to almost if not all living creatures, from the simplest to the most complex, because all living creatures depend for their survival on a mechanism that allows them to store nutrients when they are available for consumption but not needed by their metabolism, in order to live through periods where food is not available. This is why the role of insulin is so fundamental and why it is a master hormone around which most others adjust themselves. But when glucose levels are higher than a minimum functional threshold, what insulin is trying to do, in fact, is to clear away the glucose circulating in our bloodstream.

Why? Because the body simply does not want large amounts of glucose in circulation. In fact, it wants blood glucose to be low, very low, as low as possible. And beyond this very low threshold of glucose concentration between 60 and 80 mg/dl, it always tries to store it away, to clear it from the bloodstream, to make it go away. It tries to store as much as possible in the muscles and the liver as glycogen, and converts the rest to fat stored away in fat cells. That the body does not want glucose in circulation is most certainly related to the fact that the insulin mechanism even exists: very small amounts of glucose in the bloodstream is essential for life, but large amounts of glucose in the bloodstream is toxic. And all simple and starchy carbohydrates stimulate the secretion of insulin from the pancreas.

Keep in mind that the presence of insulin promotes the storage of glucose, but also of proteins as well as fats. Once more, its role is to store away and deplete the “excess” nutrients in the bloodstream for later times of food scarcity. Once the insulin molecule has delivered its load (glucose, protein or fat) through the receptor on the cell, it can either be released back into circulation or degraded by the cell. Degradation of circulating insulin is done by the liver and kidneys, and a single molecule will circulate for about 1 hour from the time it was released into the bloodstream by the pancreas until it is broken down.

It is important to add that stress stimulates the secretion of stress hormones that in turn stimulates the release from and production of glucose by the liver, just in case we need to sprint or jump on someone to save ourselves. Obviously, the presence of glucose—now not from ingested carbohydrates but from the liver itself—will trigger the secretion of insulin in exactly the same way as if we had eaten sugar. This means that stress mimics the physiological effects of a high sugar diet. And that’s not good. In fact, it’s pretty bad.

Chronically elevated glucose levels lead to chronically elevated insulin levels. And this is much worse. Like for any kind of messenger mechanism—as is insulin, if there are too many messengers repeating the same message over and over again, very soon they are not heard well because their efforts at passing on the message becomes more like background noise. Frustrated that they are not taken seriously, the messengers seek reinforcements in numbers to be able to pass on their message more forcefully. This, however, leads to even more annoyance on the part of the listeners—the message recipients—that now start to simply ignore the message and the messengers. This process continues to gradually escalate up to the point where the terrain is completely flooded by messengers yelling the same thing, but there is no one at all that is listening because they have insulated their windows and doors, and closed them tightly shut.

Here, the messengers are the insulin hormone molecules secreted by the pancreas and coursing throughout the body in our veins and arteries; the message recipients are our cells: muscle tissue, liver and fat cells; and the message itself is “Take this sugar from the bloodstream, and store it away. We don’t want this stuff circulating around.” The desensitisation—the not-listening—to different, progressively higher degrees with time, is called insulin resistance. Finally, the complete ignoring by the cells of the message and the messengers is called type II diabetes.

Furthermore, insulin resistance—not in the muscle, liver and fats cells, but in the brain cells—clearly leads to neurological degradation identified as cognitive impairment, dementia, Alzheimer’s or whatever other terms are used. Because beyond the fact that type II diabetes and Alzheimer’s disease are both increasing together at an alarming rate in the US and other western countries, and beyond the fact that diabetics are at least twice as likely to develop Alzheimer’s compared to non-diabetics, the basic condition of insulin resistance inevitably leads to chronically elevated glucose concentrations simply because the cells do not allow the glucose to enter. And it is well known that glucose in the blood simply and straight forwardly damages to the lining of the blood vessels, which then leads to plaque formation—the body’s repair mechanism for the damaged cells underneath. Thus, as are the coronary arteries of advanced atherosclerotic heart disease sufferers (and diabetics): riddled with plaques, so are the arteries and blood vessels in the brains of Alzheimer’s sufferers (and diabetics).

Now, although many claim that these and other issues related to the development of Alzheimer’s disease and other kinds of neurological degradation are still relatively poorly understood, as far as I’m concerned, it’s all the evidence I need: Do you want the vessels supplying blood to the brain fill up with plaque in response to the damage caused by glucose circulating in the bloodstream? Do you want the coronary arteries fill up with plaque in response from the damage caused by glucose circulating in the bloodstream? I certainly don’t. How could anyone?

What do we need to do? Very simple: just eliminate  simple and starchy carbohydrates from the diet. Concentrate on eating a lot of green vegetables, tons of green leafy salad greens; plenty of fat from coconut milk, coconut oil, nuts and seed of all kinds; and a little animal protein from eggs, raw cheese, wild fish and meat (if you chose to do so). Blood sugar will drop to its minimum, insulin will follow suit, and the body’s own repair and maintenance mechanisms will clear out the plaques, repair damaged tissues, degraded unneeded scar tissues and small tumours and recycle these proteins into useful muscle tissue, and many, many more amazing things will happen to the body that it will gradually look and feel younger and stronger as time passes. Sounds too good to be true? Just try it, and you’ll see for yourself. I guarantee it.