This has to be one of the most biased, unscientific post I’ve read in a while.
I had been waiting for someone else to pull the “unscientific” card. I'll address your concerns in their order of appearance. A bibliography is attached at the end of this response.
“By and large, carnivorous mammals across the world exhibit lower average lifespans than omnivorous creatures.” Really? Please show any evidence of this.
[http://www.demogr.mpg.de/longevityrecords/0203.htm]
This comes straight from the
Max Planck institute for Demographic Research. The average life span data for each species is supported by peer-reviewed studies.
If you look through the document, you'll notice that strictly and/or predominantly carnivorous mammals exhibit lower average life spans than their omnivorous counterparts. While I don't have the time to construct a chart which explicitly compares the two groups (or which deals with the statistical significance of the data), I will pick out some quick examples that address the underlying concerns in a succinct manner:
1) Hippopotamus (omnivorous) in relation to the lion (classic, cliche example of carnivorous animal).
2) Suborder
mysteceti whales (fin whales, blue whales, etc.) in relation to carnivorous whales.
3) Eurasian brown bear (predominantly omnivorous since the middle ages) in relation to the polar bear (predominantly carnivorous).
On a tangential note, it would seem that whales possess metabolic adaptations to predominantly carnivorous diets that allow them to live longer than most land carnivores. However, this all comes with a rather large caveat: within the whale groups themselves, the filter-feeders, or baleen whales, exhibit larger average life spans than the predominantly carnivorous species. For the baleens, consuming zooplankton means that phytoplankton is difficult to avoid, and indeed, perhaps even constitutes an important dietary element for the aquatic mammals. Zooplankton depends primarily on phytoplankton for survival, and the two are seldom found separated in the oceans. “The physical factor that influences zooplankton distribution the most is mixing of the water column…along the coast and in the open ocean….that affects nutrient availability and, in turn, phytoplankton production” (Lalli et al. 1993). At least for certain species such as the bowhead whale, research has demonstrated that phytoplankton is an important, if consequential, aspect of their diets. “Each adult [bowhead] whale consumes on the order of 100 metric tons of zooplankton prey, which in tum represents a much larger ( -10 times) biomass of phytoplankton” (Schell 2000). Finally, here is a quote from an accessible article which ties the levels of phytoplankton in the world's oceans to the diets of blue whales: [http://www.theguardian.com/environment/2010/jul/28/phytoplankton-decline-nature].
Another user on this forum (Edmon) posited that the differences in carnivore/omnivore life spans are due to the expression of the simple mechanisms of survival involved in predatory activities. To take his claims further, the logic supporting such a statement is as follows: If a hunter feasts solely on meat, then the hunter's capacity to survive is tied directly to their hunting skills, and hunting skills are tougher to maintain than grazing faculties. Edmon argued that carnivorous animals typically die while attempting to secure their prey, in fights with other predators, and of infections/other illnesses. While we can accept such an
Occam's razor-like approach to the life span problem in carnivores, and immediately cease considering a myriad variables, a series of critical, thought-provoking questions will yet remain: All things considered, why does the wild carnivore's survival functions—namely, the capacity to engage in a successful hunt, acquire nourishment, and deflect other predators, pathogens, etc.—decline at a faster rate than the omnivore's, thereby leading to observable differences in life spans? In other words, why does the carnivorous mammalian, which is supposedly well-adapted to hunting and the consumption of an all-meat diet, fail to adequately maintain its physical faculties for longer than the omnivore's? Is it simply that hunting full-time is
harder work than foraging and scavenging? What does such
harder work constitute, in a metabolic sense? Harder work in what specific terms? What of the omnivores, who hunt, scavenge, and forage, depending on the seasons, their needs, desires? Capturing live prey obviously involves a great deal of exertion and stressors, but are the lion's overall stressors necessarily greater than the hippo's
per se?
The emergence of these questions led me to the eventual exploration of the mechanisms of action involved in the mammalian body's metabolic pathways. Before I get into the theoretical and scientific underpinnings of my section dealing with the human’s metabolic pathways, let me tackle your point regarding "the validity of a diet to optimal health:"
And even if this was true, it means nothing about the validity of a diet to optimal health. Optimal health means heath level during life, not how long that life lasts.
Since I refuse to play a game of semantics, I'm going to assign a very specific definition to my usage of the concept of optimization, so that there may be no confusion regarding what I'm referring to.
Optimization involves the process of making something as effective, sustainable, and fully-functional as possible. The optimization of a system refers to the maximization of productivity and the minimization of refuse. In the context of my discussion, optimization is directly tied to temporal sustainability, and therefore, by extension, to life span.Simply put, the form of optimization that I seek does not only account for the short-term benefits of efficiency; I am far more compelled by the notion of efficiency as it relates to sustainability and longitudinal performance. Thus, I initially frame optimization within the context of life span because I am asking how we can optimize both the quality
and duration of human life. You seem to be arguing that the quality of a life is all that matters for an organism's existence. In this sense, it does not matter whether a person lives past their forties, so long as they have experienced an acceptable level of health throughout their active moments. I disagree with this rather simplistic and limited conceptualization of health and optimization. My argument attempts to push beyond the strictly qualitative domain and into the temporal and quantitative.
Mice are herbivores, but they live less long than a cat that feeds on them, if they both die of old age.
I’m not exactly certain as to why you are bringing up herbivorous mice. At no point did I address the life spans of herbivorous species. However, if we want to go down that road, then I will note that
large mammalian herbivores, such as ruminants, do tend to live longer than
large carnivores (where ‘large’ refers to animals bearing an average body weight of over 150 lbs.), if subjects are allowed to die strictly of old age. But—and this is a huge but—the encephalization quotients, as do the brain sizes, of herbivores (Deaner et al. 2007; Nelson et al. 2001) tend to be much lower than omnivores and carnivores, thereby revealing an apparent deficit in the cognitive abilities of the herbivorous group—which would make sense from an evolutionary perspective that considers brain growth as tied to the consumption of animal proteins and fats.) Of course, we can get into extended and unfruitful discussions of what constitutes intelligence within a particular species. For the sake of simplicity, I am using the rubrics of the encephalization quotient and total brain size to describe mental processes as they become appreciable to our human understandings of intellect.
The evolutionary ideas, while “somewhat” valid as empirical evidence (is there any evidence that animals in the wild tend to eat what is best for them?
It does not matter whether you believe that “animals in the wild tend to eat what [is or isn’t] best for them.” (Although there are numerous people on this forum—“instinctos”—that will strongly dispute this point in relation to human evolution.) The point of my discourse is to emphasize the fact that countless years of human evolutionary adaptations have laid the biological foundations for the execution of a potential diet which utilizes rational, historically-valid reasoning to provide the body with its optimal requirements. You are attacking my usage of evolutionary ideas by mobilizing a completely unrelated assertion. Evolutionary theories do not
ipso facto rely on optimization apparatuses to describe animal bodies; evolutionary theories present us with frameworks for approaching the adaptations and survival dynamics that allow for the reproduction, transformation, and destruction of a species. I am drawing on evolutionary theories insofar as they reveal the present conditions of human metabolic pathways, and allow for us to make informed judgments regarding the optimal means by which to expand the living performance of bodies. I am not, as you crudely assume, drawing on evolutionary theories to supply evidence for the supposed “natural” existence of optimization mechanics in the “wild.” Do not misconstrue my words.
However, no one knows what earlier humans ate. It’s all guesses and suppositions. They had element “X” in their environment, it’s edible, they probably ate it. Again, why would people assume that they would eat what is good for them rather then what they might stumble upon is beyond me.
Absolutely irrelevant to my argument. I highly doubt that ancient humans were thinking of how to grow larger brains when they decided to hunt other animals. I would not be so naïve and foolish to claim this. Rather, the evolutionary result of the ancient human’s dietary decisions contributed, directly and indirectly, to the development of specific bodily facets—namely, the larger brain. Evolution is not akin to optimization, but dietary optimization theories must draw on evolutionary knowledge to pass grounded judgments. Your failure to grasp my assertions makes me wonder whether you even read my opening post before engaging in this unfounded collection of attacks.
Worse, using arguments of authority is dishonest. “reading up on a great deal of scientific studies and informal experiences” What’s that supposed to mean? Every doctor I’ve ever heard talk about nutrition…
I don’t even feel the need to quote that statement in its entirety. Your ad hominem tactics are infuriating, at the very least, and, at most, rather disheartening. Considering the overt assaults on my character, if your response to my post were to appear in a scholarly journal, I would feel no need whatsoever to offer you a rebuttal. Thankfully, this is a public forum, and I’ll gladly humor your offensive reply for the sake of fostering public knowledge.
I am not marshaling “arguments of authority” in any way whatsoever. If your definition of arguments of authority means that I declared my knowledge of the subject that I am describing, then yours is truly an atypical approach to the expression. The reason why I stated that I read up on a significant number of scientific studies and informal experiences is because I
did. As for informal experiences, my own encounter with a sustained ZC diet has led to heart issues that I am still recovering from. At several moments throughout my ZC experiment, I was dealing with ridiculous and unexplainable palpitations; my extremities were becoming cold, my emotions were receding, and I was consistently irritable. If you would like to talk about the problems that others have experienced while on a sustained ZC diet, just ask PaleoPhil about the symptoms that he dealt with. On Carbsane and other forums, informal evidence for symptoms of what has been termed “VLC/ZC torpor” have emerged as well. PaleoPhil, I’m sure, would be glad to provide you with actual links to the pages where people talk about their problems while on ZC diets.
Regarding the formal underpinnings of my theories, I have drawn on specific scientific studies which demonstrate the inefficient properties of gluconeogenesis (Hendrick et al. 1990; Veldhorst 2009; Veldhorst 2012; Baba et al. 1994) while in a deep ketogenic state (Tagliabue A 2012), and relative to glucose metabolism (Mcdonald 1998; Prince et al. 2013); as well as revealing the difficulties associated with the production of glucose from fatty acids (Kaleta et al. 2011); and the limitations on the potentially therapeutic overall uptake of ketones by the brain (Devivo et al. 1978; Seyfried et al. 2003; Lahanna et al. 2009; Cahill 2006). All of these studies address periods of deep ketosis as exceptional for the mammalian body, with Lahanna (2009) and Seyfried (2003) particularly making use of such exceptional circumstances to augment the validity of their experimental procedures. Taken in tandem, these studies point to the short-term therapeutic benefits of a ZC or VLC diet (for the metabolically deranged, epileptic, etc.), but direct us toward challenging the long-term metabolic stressors that arise from the sustained inefficiencies of the aforementioned key metabolic pathways. I will return to this last point soon.
The body does not tend towards an optimal state. It maintains a “minimal” state. Enough to not die, nothing more. Lie down in a bed for a few months, eating the best diet you can. Your bones will still end up brittle, your muscles will be almost inexistent. Even if you eat a lot of protein and fat. Why? Because your body does the least in can if it has the option.
The body tends toward homeostasis, which is absolutely different from the “minimal” caloric state that you are describing. Your definition of minimal begs interrogation. If you are defining the human’s basal caloric requirements as being constitutive of a minimal state or set-point, then even at this level, homeostasis involves a conglomerate of intensely erratic, fluctuating processes. Homeostasis is about balancing and stabilizing the entropic reactions of a semi-structured body. Confronted with an obviously necessary minimal caloric intake (which is about the only minimal element of a human existence), the entropic body incessantly attempts to adapt and respond to the chaos generated both by and within metabolic processes.
Homeostasis, for one, cannot be separated from hormesis, which details the body’s responses to disordered metabolic chains. Even the subject lying on a bed will be exposed to organic stressors (atrophy, etc.) that cause their body to reflexively manipulate key metabolic pathways in response to sedentary functions. Oftentimes, these metabolic pathways involves seriously disruptive physical processes that make maximum use of inefficient metabolic structures, such as gluconeogenesis and ketosis, and which may not contribute to the optimal health of the subject, but which certainly allow for the subject to survive and adapt.
This is all to say that what you perceive as the body doing “enough to not die,” is actually the body doing
enough to survive and reproduce; and there is a massive, indisputable difference between these two expressions. Your fatalistic approach to human existence is wholly unsupported by science. Humans have been shown to possess psychological and physical regulatory mechanisms that further the pursuit of reproduction, survival, and survival beyond reproduction. The body does the most it can to survive and reproduce, not the least it can to ward off death. The body, in fact, is not concerned with life and death--this Christian dichotomy that so many scientists submit to. The human body, the mammalian, animal body, is invested in the protection of reproductive faculties that are inextricably bound to the adaptive survival of an entropic organism. Survival is about adaptation and reproduction, not death and a minimalistic quality of degeneration.
So the fact that gluconeogenesis and ketosis are very inefficient (on a calorific) and taxing (on the organs) is irrelevant. That’s like saying that a jet is not optimal because it consumes too much energy and stresses its components, so a bicycle is better.
The underlying logic here is absolutely flawed. You moved from A to B without adequately connecting the two thoughts.
A) "The body does not tend towards an optimal state. It maintains a “minimal” state."
B) "So the fact that gluconeogenesis and ketosis are very inefficient (on a calorific) and taxing (on the organs) is irrelevant.
So, “if the body does not tend towards an optimal state,” then “the fact that gluconeogenesis and ketosis are very inefficient…and taxing on the organs….is irrelevant.”
What? How have you established the irrelevance of point B in relation to point A? In legal-speak, this is what we call a non-sequitur.
The notion of a minimal state serves no purpose in addressing the particular metabolic inefficiencies of gluconeogenesis and ketosis. As I stated above, the only minimal state in the human body is the basal need for calories that defines survival. To reiterate: optimization, as per my discussion, entails rationally reflecting (an anti-‘natural’ process) on the specific qualities of metabolic pathways so as to determine their maximum performance levels in relation to life spans and health.
That’s like saying that a jet is not optimal because it consumes too much energy and stresses its components, so a bicycle is better.
Do you really want to get into the thermodynamics of using petroleum to power jets? I'm just going to marginalize this. By all means, keep believing that jet planes are efficient machines.
If you are going to take your own arguments as a basis for optimal behavior, then you should be against exercise. After all, exercise is inefficient, it taxes many organs, including the heart, wastes energy, and produces many “dangerous” chemical reactions.
Now we are getting deeper into ad-hominem territory. That's fine, though. I'll play along.
To begin with, I am not against exercise, and at no point did I imply or state this. Most exercise does not involve a sleuth of chronic stressors, and exercise satisfies many of the hormetic requirements of a homeostatic system. Hormesis, though, is not the same as systematic degeneration. Provided that a body is properly nourished, exposure to exercise allows for the optimization of life span and health viz. the enhancement of metabolic flexibility. Many forms of exercise satisfy the conditions of adaptive and sustainable optimization that I embrace within my writings. I am, without a doubt, against endurance training, for I believe (as do other scholars) that it places undue stress on the organ systems of the human body (Benito et al. 2011; Wilson et al. 2011). Do you see the difference here? There is a huge gap between short-term hormetic stressors and chronic degenerative stressors.
The very fact that gluconeogenesis is associated to cortisol levels should send up some red flags” So again, are you against exercise? Exercise is strongly associated to cortisol levels. Cortisol is associated with stress. Stress is good for the body. Absence of stress is bad. Why don’t you tell astronauts how the absence of stress on their joints is good for them?
You are foolishly misconstruing my arguments. I am not claiming that short-term stressors are unnecessary for human health; I am writing against the long-term stressors emerging from a chronic ZC diet and its inefficient metabolic pathways. The reason why cortisol sends up a red flag in relation to gluconeogenesis is because while in a
deep ketogenic diet, a subject is constantly engaged in gluconeogenesis, and therefore exhibits elevated cortisol levels (Swain et al. 2012). Dichotomizing stress as good/bad is a ridiculous proposition. Stress is neither good nor bad; stress is a physical signifier that directs our attention toward bodily processes that may indicate the absence or presence of particular adaptive mechanisms. I have opted to question which adaptive mechanisms are optimal for both longevity and maximum health.
However, if you want to argue along the dichotomy of “stress is good” and the “absence of stress” is bad, you’d do best to research how the body deals with the elevated cortisol levels of exercise. A little hint: as the body becomes used to stressors, cortisol levels begin to decrease. Chronically elevated cortisol levels are a serious problem, leading to heart disease, etc., but cortisol released in response to short-term stressors allows for the body to adapt to the demands of exercise.
Retrieved from: [http://www.livestrong.com/article/86687-exercise-cortisol-levels].
Negative Effects [of cortisol]
Unfortunately, the negative effects of cortisol outweigh the positive. Cortisol has an immunosuppressive effect, meaning that if your body constantly has high levels of cortisol, you are more susceptible to illness or infection. Also, because cortisol is a response to stress and the goal is to increase fuels in the blood, it will increase blood calcium by inhibiting bone formation and decreasing intestinal calcium absorption. This may result in a decrease in bone density over time. Cortisol also inhibits the pathway that releases sex hormones (gonadotropins), so if you are constantly stressed, you may experience a decreased libido and, in some cases, infertility or difficulty conceiving. Women who have high levels of cortisol in combination with low body weight may have amenorrhea (loss of menstrual cycle).
Training Effects
Because cortisol is released in response to stress, exercise training will increase the threshold of cortisol release. For example, if you begin an exercise program walking at a 20-minutes per mile pace, cortisol will be released at that intensity. However, as your training progresses and you begin walking at a 15-minutes per mile rate, the body will not perceive the 20-minutes per mile pace to be as stressful and will not release as much cortisol. Finally, telling people that they should seriously switch their diets if they start feeling sick is irresponsible. People get sick irrespective of their diets. You trying to be an authority on what people should or should not do is laughable.
Using the internet’s anonymity to make hostile, assumptive statements against my intents involves a great deal of cowardice, to say the least.
When did I say that anybody should stop eating a ZC diet? I was trying to help others on this forum by presenting my theories and understandings of the problematic attributes of a chronic ZC diet. I am not trying to brainwash or control anyone. Do whatever you want. If you feel fantastic and want to continue on the ZC diet, then by all means, go right on ahead. I am presenting people with my understanding of what an optimal human diet does and does not contain, and my conclusions are, despite what you may believe, supported by science.
I know I said finally, but I lied. Here is some pure wisdom: The true optimal form is to be dead. Then you consume nothing, you experience no stress, and you have no chance of having any disease.
The so-called purity of your wisdom leaves much to be desired.
But that is not what I want. I want to be as strong and vigorous as I can. I don’t seek to be free from pain and stress, I want for everything that doesn’t kill me to make me stronger. I don’t want an easy life, I want the strength to endure a hard one.
I applaud you on the rhetorical flourish; truly, I was nearly brought to tears.
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