This chapter uses the term luteal phase deficiency LPD.
Did CHOs make us human? I doubt it "I like to start with an evolutionary perspective" — Jennie Brand-Miller Today at the Food for Thought ConferenceJennie Brand-Miller argued that dependence on exogenous glucose played a critical role in our evolution. I and others disagree for several reasons. Let's look at the main arguments Brand-Miller put forward in support of exogenous glucose.
The brain requires a lot of energy The brain runs on glucose The need for dietary glucose is particularly acute in fetuses The cooking of starch allowed us to get that energy Some modern HGs make significant use of exogenous glucose We have many more copies of amylase than other primates Some of us have developed persistent lactase We are hard wired to love sweetness Yes, the brain requires a lot of energy; no it does not have to come from dietary glucose I agree wholeheratedly that our brains require a lot of energy, much more than other organs, and that our needs are many times more acute than in other primates.
Getting this energy was critical for our evolution. However, the idea that the brain "runs" on glucose, and that this shows a requirement for exogenous glucose is incorrect, and omits well-known evidence. First, our bodies are capable of synthesising enough glucose in the absence of dietary sources to fulfill the most conservative estimates of requirements.
As conceded early in the presentation, we are known to be able survive without exogenous glucose. If we could not supply our brain needs in this way, this would simply not be Hypothesize why some substances were not metabolized while others were research the.
That glucose is mostly synthesised out of protein, and the process is called gluconeogenesis.
This fact alone is enough to render this argument irrelevant, but there is more. In the situation for which no dietary glucose is provided, not only can we still make enough glucose endogenously to meet those needs, but in practice what happens is that our needs are different.
Instead of running primarily on glucose, our brains metabolism runs mostly on ketone bodies, and uses glucose for only a small portion of its needs, far less than our capacity to generate it. Fetal and infant growth does not depend on dietary glucose Brand-Miller also insists that "The fetus grows on the mother's maternal blood glucose.
However, she neglects to mention that fetuses make extensive use of ketones. I've covered infant brain growth and the importance of ketone bodies in this context several times, so I won't go into it here.
See Babies thrive under a ketogenic metabolismMeat is best for growing brainsWhat about the sugars in breast milk? In any case, maternal blood glucose is maintained just fine without dietary sources, so even if babies did not use ketones, the point would be moot.
The evolutionary argument Since our brain energy needs are met perfectly well with either a high glucose intake or a low glucose intake, it cannot be reasonable argued that our large brains must have developed under conditions of high glucose intake.
There are still at this point two equally plausible evolutionary hypotheses that would enable the evolutionary development of large brains: An increase in both is also a plausible hypothesis, either together or in alternation.
For simplicity, let's start by considering one state or the other as being the predominant evolved state.
Let's review what evolutionary circumstances would be required for each hypothesis, and what other circumstances would support it without being necessary. Then we can see what evidence we have for those circumstances.
Persistent adequate availability of the predominant energy source and essential micronutrients For the exogenous glucose condition to have been the predominant evolved state, we would have required a consistent source of exogenous glucose on a regular basis, year round, for multiple generations.
For the endogenous glucose condition to have been the predominant evolved state, we would have required a consistent source of exogenous fat and protein on a regular basis, for multiple generations.
The reason we would need fat, and not just protein in the gluconeogenesis case, is that we are limited in our ability to metabolise protein. Protein is better conceived of as a mainly a micronutrient, rather than a macronutrient, because of its structural importance. Besides water, our bodies are primarily made of amino acids and fatty acids.
This is one reason why when we rely on gluconeogenesis for all of our glucose needs, we also have reduced glucose needs. It spares protein for more important things. Protein availability is also of crucial importance even for the exogenous glucose hypothesis, because it is still a fundamental nutritional need outside of energy requirements.
Beyond protein, we would need to supply all of the nutrients that proper brain development requires. These include the minerals iodine, selenium, iron, zinc, vitamins B12, A, and D, and the vitamin-like choline, and the fatty acids DHA and arachadonic acid. Note that of the minerals listed here, animal sources are much more bioavailable, and that plant sources contain substances that actively interfere with absorption.
Of the vitamins and fatty acids, one B12 is not available even in precursor form, and the others only in precursor form. Humans are known to have low and variable ability to synthesise the necessary components out of precursors.
It is generally agreed upon in the scientific community that because of these hard requirements of the brain, a significant level of animal sourced food must have been part of our evolutionary heritage. This is supported by the absence of evidence of a single indigenous society that did not include some form of animal sourced food.
If the energy source were dietary glucose, we would require: First, tubers in existence were seasonal and limited in supply. Second, tubers in existence were highly fibrous, much more so than today's bred varieties, so they didn't yield much . The wild type still used by the Hadza, for example, have a low yield of glucose even when cooked.
According to Schnorr, who studied this, "When roasted, they produce more energy, although the difference is not great.The evolutionary argument.
Since our brain energy needs are met perfectly well with either a high glucose intake or a low glucose intake, it cannot be reasonable argued that our large brains must have developed under conditions of high glucose intake.
Hypothesize why some substances were not metabolized, while others were. Research the chemical formula of Equal™ and Splenda™ and explain how it .
1. Hypothesize why some substances were not metabolized, while others were. Research the chemical formula of Equal and Splenda and explain how it would affect respiration. The substances that were not metabolized cannot be used by the body in the process of cellular respiration. They cannot be inserted into the process at any point.
1. Hypothesize why some substances were not metabolized, while others were. Research the chemical formula of Equal and Splenda and explain how it would affect respiration. 2. If you have evidence of respiration, identify the gas that was produced.
Suggest two methods for poistively identifying this gas. %(1). Many of you have probably heard of the ‘alkaline diet’. There are a few different versions of the acid-alkaline theory circulating the internet, but the basic claim is that the foods we eat leave behind an ‘ash’ after they are metabolized, and this ash can be acid or alkaline (alkaline meaning more basic on the pH scale).
According to the theory, it is in our best interest to make sure. Hypothesize why some substances were not metabolized, while others were. Research the chemical formula of Equal™ and Splenda™ and explain how it would affect respiration. • Theobromine an enzyme, cannot be processed in the body, but it is ingested quite often because it is an enzyme found in chocolate.