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How did we get large brains with a small gut?

Here is a chart that shows the profound difference in brain size and its relationship to gut size.

Note, the gut mass of M. Greger is larger compared to H. sapiens because he is mostly FOS!**

** I pick on Greger because he is a vegan who misrepresents data to support his thesis.

The article presents the "Expensive Tissue" Hypothesis which states that the energy expended in a large gut takes away from the high needs of the brain. This makes no sense, yet it is published - go figure. Dr. Wrangham explains the actual reason for the small gut of H. sapiens.

Dr. Richard Wrangham from Harvard explains that cooking is the differentiator.

My disagreement with his thesis is his emphasis on energy. Our brains are VERY energetic, about 10 times more than the average of all our tissue. However, since the brain is only 2.5% the mass of our entire body, the "10 times" reflects only a small increase in energy needs. The real difference is the need for micronutrient density. It is futile to have excess energy without a way to process it and repair the damage created by high activity - just like in an athlete who is constantly breaking down and rebuilding tissue. This 'futile" state of excess energy, without adequate nutrients, is called diabetes. These people have a huge intake of "energy" (calories) but lack the ability to process it because of a lack of micronutrients.


Previous Blog on This Topic.

Yes, I am suggesting you avoid salads, but saute those vegetables instead (with lots of butter or other healthy fats)

Cooking (heating) foods should be the first step in digestion. Cooking “tenderizes” by breaking down the complex food structures. That is what digestion does too, except in digestion, the food is completely liquified. Cooking kale to create a softer, more palatable form takes quite a while. It is quite “starchy” and resists the action of heat to break it down.

Harvard primatologist Richard Wrangham weighs in on the importance of cooking and how it advanced humans over other creatures.[i] He states, “The biggest revolution in the human diet came not when we started to eat meat but when we learned to cook. Our human ancestors who began cooking sometime between 1.8 million and 400,000 years ago probably had more children who thrived,” Wrangham says. “Pounding and heating food “predigests” it, so our guts spend less energy breaking it down, absorb more than if the food were raw, and thus extract more fuel for our brains.”

“Cooking produces soft, energy-rich foods,” says Wrangham. “Today we cannot survive on raw, unprocessed food alone, and we have evolved to depend upon cooked food.” When compared to a cow that eats raw grasses and has four compartments in its stomach, humans have just one small one. Cooking is a substantial reason for that difference.

Although the bioavailability of some nutrients is fairly well understood, for other nutrients, the scientific understanding of uptake, absorption, and bioavailability in humans is still at a nascent stage. Not all micronutrients are well absorbed, even in apparently healthy people. Many apparently healthy people have mild gut issues that impact the rate and efficiency of digestion and don’t even know it. This presents a problem in the absorption of, for example, green leafy vegetables. These foods are rich in iron, but the bioavailability of iron is relatively low—around 12%. This is an average value and is higher in those with good digestion and lower in those with poor digestion. A sign of poor digestion is any common gut-related issue, including diarrhea, constipation, gas, bloating, and acid reflux.

According to Melse-Bonstra, in an article titled, “Bioavailability of Micronutrients from Nutrient-Dense Whole Foods: Zooming in on Dairy, Vegetables, and Fruits,[ii] “The low bioavailability is attributed to the indigestibility of cellular components such as chloroplasts and mitochondria where iron is stored. Poor absorption of micronutrients creates a deficiency that affects physiological processes leading to a myriad of diseases.”

Poor iron absorption may lead to anemia, which is a blood disease associated with low iron levels in the blood. Anemia is a common disease that affects ~1.6 billion people worldwide, especially infants and women. The World Health Organization (WHO) has estimated that the global prevalence of anemia in women is nearly 30 percent.[iii] Mayo Clinic states,[iv]

“This most common type of anemia is caused by a shortage of iron in your body. Your bone marrow needs iron to make hemoglobin. Your body can't produce enough hemoglobin for red blood cells without adequate iron. Without iron supplementation, this type of anemia occurs in many pregnant women. It's also caused by blood loss, such as from heavy menstrual bleeding; an ulcer in the stomach or small bowel; cancer of the large bowel; and regular use of some pain relievers that are available without a prescription, especially aspirin, which can cause inflammation of the stomach lining resulting in blood loss. It's important to determine the source of iron deficiency to prevent recurrence of the anemia.”

Could it be that the many causes listed by Mayo are not the predominant root cause of anemia? It is possible, based on the science of digestion and absorption, that the most prevalent cause of anemia in poor digestion? Taking an iron supplement in pill form may not solve the problem because it may not be broken down and absorbed, just like the iron in a food. Our medical professionals, who focus on gut health, indicate that many cases of anemia resolve when improved digestion is the focus of their therapeutic interventions.

Cereal grains constitute about a quarter of our calorie intake. Unfortunately, the type of cereal grains consumed in the United States are refined and have a high glycemic load. Our hunter gathers ancestors did not eat cereal grains. It was impractical for them because the amount of energy required to harvest them offset the energy they provided. Cereal grains are the seeds of grasses, and in their wild state, they're very small and difficult to harvest. Once harvested in their natural form, that are not edible. They must be ground and cooked otherwise the starch and protein they contain is not bioavailable through digestion.

Crude grinding stones were used roughly ten to fifteen thousand years ago, which led to grains being slowly introduced to a limited population. The industrial revolution leading to more sophisticated grinding devices led to broader availability of flour as a food. Waterwheels that turned gears that ground stones together to make flour led to mass production and wide availability of this food but flour did not have evolutionary adaption connect to it. The high consumption of flour occurred just recently.

Wheat has reasonable nutritional value tied up in the germ and the bran. Modern technological developments increased wheat processing throughput while removing the germ, bran, and the micronutrients they contained. Whole wheat kernels have a low glycemic index but the refined flour products have a high glycemic index. In addition, these foods disrupt a proper acid-base balance in the gut and blood.

The right pH is critical to health and these grains interfere with this balance. All grains are net acid yielding and these foods tend to promote osteoporosis, indicating poor mineral availability that is influenced by gut and blood pH. Fruits and vegetables are the few alkalinity producing foods, and too of these foods are consumed in sufficient quantity to overcome the acidifying effect of the wheat-based foods. Thus, the Western diet is net acid yielding.

Osteoporosis is actually the least of the conditions caused by an acidic milieu. Dr. Otto Warburg, winner of the Nobel Prize in 1931, discovered that cancer cells are not fueled by oxygen as are normal cells. The high levels of oxygen that are found in healthy, alkaline bodies are toxic to cancers. He found that cancers get their energy from sugars and a process of fermentation in acidic environments. He proved empirically the relationship between cancers, acidic body pH, and cellular oxygen starvation. His findings demonstrated that cancers are merely a symptom of acidosis, and therefore it is impossible to truly cure any cancer without first curing the underlying acidosis.

John Kellum, author of “Determinants of Blood pH in Health and Disease,” explains three key factors that regulate blood pH.[v] One of the “big three” is “relative electrolyte concentrations.” Electrolytes means minerals and it is clear that minerals are difficult to absorb. Thus, our society has the cascade of ailments driven by improper blood pH. Kellum states:

“An advanced understanding of acid–base physiology is as central to the practice of critical care medicine, as are an understanding of cardiac and pulmonary physiology. Intensivists spend much of their time managing problems related to fluids, electrolytes, and blood pH. Recent advances in the understanding of acid–base physiology have occurred as the result of the application of basic physical-chemical principles of aqueous solutions to blood plasma. This analysis has revealed three independent variables that regulate pH in blood plasma. These variables are carbon dioxide, relative electrolyte concentrations, and total weak acid concentrations. All changes in blood pH, in health and in disease, occur through changes in these three variables. Clinical implications for these findings are also discussed.”

In patients with chronic generalized periodontitis, the salivary pH is more acidic than the control group and this explains why many cancers are also associated with poor oral health and periodontal bacteria. Charles Mayo, the founder of the Mayo Clinic, focused a substantial portion of his medical career on the impact of infected teeth on chronic health. Mayo used the term “focal infection” to explain that diseases caused by periodontal bacteria outside of the mouth, were not necessarily systemic, but rather localized in nature. Kevin J. Carlin brings our understanding of focal infections to a new level and are related to physiological pH levels.[vi]

“Why do certain infections tend to recur in the same area? For certain at least part of the explanation is opportunity with the infectious agent's location close at hand or an enhancing delivery system. Also, certain adaptations by the infectious agent occurs leading to specific locations. But perhaps there is an additional unknown preference that at least on occasion may be involved. Few are surprised Candida albicans episodically grows on skin, in urine and in the female vagina since these areas are all known to be acidic at times and Candida prefers an acidic environment for growth. But we do not use the same logic for example when an infectious agent grows in the adrenals or bone well away from the original lung location.“

Not surprisingly, lower blood pH, tied to poor mineral absorption and low nutrient density consumption, is a strong prognostic factor for fatal outcomes in critically ill COVID-19 patients. Kieninger et. al. explain that pH and arterial pressure are more important compared to other risk factors is COVID-19 patients.[vii]

“In this retrospective cohort study, we analyzed the first 59 adult critically ill Covid-19 patients treated in one of the intensive care units of the University Medical Center Regensburg, Germany. Using uni- and multivariable regression models, we extracted a set of parameters that allowed for prognosing in-hospital mortality.

Within the cohort, 19 patients died (mortality 32.2%). Blood pH value, mean arterial pressure, base excess, troponin, and procalcitonin were identified as highly significant prognostic factors of in-hospital mortality. However, no significant differences were found for other parameters expected to be relevant prognostic factors, like low arterial partial pressure of oxygen or high lactate levels. In the multivariable logistic regression analysis, the pH value and the mean arterial pressure turned out to be the most influential prognostic factors for a lethal course.”

These data present a strong argument for optimizing gut microbiome, digestion, and micronutrient intake, with emphasis on foods high in mineral content to combat the most serious diseases.

Dr. Mat Lalonde is an expert on foods and their micronutrient density. He holds a Ph.D. in Organic Chemistry from Harvard University. He evaluated many of the modern dietary styles for nutrient density and determined that most claims made about dietary nutrient values were flawed. He created his own scale, using evidence-based algorithms, and included weighting factors for each – all based on micronutrient levels, as opposed to macronutrient density.[viii] This table presents his findings.

[ii] Melse-Boonstra A. (2020). Bioavailability of Micronutrients From Nutrient-Dense Whole Foods: Zooming in on Dairy, Vegetables, and Fruits. Frontiers in nutrition, 7, 101.

[iii] WHO Global Anaemia estimates, 2021 Edition

[v] Kellum, John A. "Determinants of blood pH in health and disease." Critical care 4.1 (2000): 1-9.

[vi] Carlin, Kevin J. “Infections and pH.” Austin J Infect Dis. 2014;1(1): 2.

[vii] Kieninger, Martin, et al. "Lower blood pH as a strong prognostic factor for fatal outcomes in critically ill COVID-19 patients at an intensive care unit: A multivariable analysis." PloS one 16.9 (2021): e0258018.


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