Inlightenment: Light & Nutrition
Dr. James Karl Fischer PhD Friday, March 12, 2021
Overview
In this installment of Inlightenment, we consider the impacts of light on nutrition, one of the key domains of animal welfare. The goal as always is to encourage zoos and aquariums to measure light as a preventative healthcare strategy, but the importance of such measuring is crucial for communities that seek to live better with animals too. Here are four key points that the article below explores:
- Photobiology is all important to positive nutritional outcomes, and so to positive mental affect.
- Environmental light governs the opportunistic and homeostatic aspects of nutrition, as neurological and endocrine systems function through ocularly governed feedback mechanisms.
- Considering animals as open systems, connected to their environments as biological feedback loops, raises the importance of the five phases of nutrition taken for mental well-being. Animal care specialists are encouraged to understand the internal and external photobiology of animals in their care, according to the phenological natural history of animals as well as their specific physiological, sensorial, and integrative photo-biology.
- Conceiving nutrition in this way, opens a path to a specifically Japanese concept of animal welfare, recognizing the ‘partaking in’ of life, rather than detached management of it. This will become important when we turn to questions of health in subsequent releases.
Introduction: A Lucid Approach to Nutrition in an Open System
Nutrition and positive mental affect go hand in hand.
Anyone who has ever fasted, abstained, overindulged, or even changed their diet to lose a few stone realizes this. Humans on the brink of starvation, as the Dhammacakkappavattana Sutra tells us, cannot reach a mental state of enlightenment, and the affective differences between ingesting a well balanced diet versus psychedelic mushrooms or refined sugar, is self-evident. In another context, the Last Supper precedes the abstinences of Good Friday, leading to the breaking of Bread, and the bonding of a community of saints beyond the imperatives of mere ‘survival’. Nutrition is important. Nutrition and positive mental affect go hand in hand, far beyond a simplistic notion of fuel.
Nutrition is a core aspect of positive mental affect, and so of positive animal welfare. And as we focus on ‘the eye’, for animals eat with their eyes as much as they do their mouths and bellies, we also need to explore nutrition as a holistic process rather than simple intake.
We are ‘what’ we eat, but it is also true that we are ‘how’ we eat, and ‘when’. At its most basic level, when we speak of nutrition, we are talking about the transformation of environmental substances through and by living organisms, insofar as all life and living beings are open systems connected to their environments in decisive and knowable ways. Although we often isolate the mere absorption of food as the important bit, nutritious welfare involves so much more. That point was worth repeating, because natural light is important to this processing in a variety of ways.
Natural light serves as both setting and resource for nutrition and the processes that make it up. Animals acquire, process, absorb, assimilate (into behaviors and functions), and eliminate food. The CS_PCPT System, consciousness bonded to perception, is of necessity caught within visual perception; of vision insofar as the eyes are tailored to specific prey at specific times in specific environments according to specific relationships. Light, quite obviously, is important for the superficial level of targeting, capturing, and ingesting food for all animals with eyes. Yet light and natural light conditions are vital to the internal processing of food as well, impacting the CS-PCPT system from both sides at once, as it were.
We ought to say something more of ‘nutrition’.
The broadest division of nutrition splits autotrophs from heterotrophs. Autotrophs can be divided further, into photo-autotrophs, which process light to decompose less useful chemicals into something that benefits fitness, and chemo-autotrophs, which do something similar using chemical compounds.
The familiar chemical equation for autotrophic photosynthesis, 6CO2 + 6H2O → C6H12O6 + 6O2, invites thoughts of thinking of nutrition in terms of open systems. In photo-autotrophs, light (EM Radiation), water, and carbon dioxide enter the system, forming sugars and eliminating oxygen as waste. In autotrophs, the intake involves inorganic materials, inorganic in the sense of non-carbon based, but the nutritious process is strikingly similar in the abstract. Inputs react, breaking chemical bonds that allow for reconstitution in forms favored by external and internal circumstance, which includes waste products.
Heterotrophic nutrition can be of three kinds; parasitic (living in or on another), saprophytic (focusing on the processing of decayed organic matter), or holozoic, (characterized by ingestion and internal processing). Heterotrophs consume other living beings, needing to take in organic matter in a kind of fundamental cannibalism, rather than drawing from light or inorganic chemicals directly. Yet, in a persnickety sense, the intake of light is as necessary for holozoic heterotrophs as it is for photo-autotrophs, as neither consumption nor assimilation could exist without it.
This remedial review is important when we think of light and animal nutrition, as we are generally referring the five step process of mouth induced ingestion, digestion, absorption, assimilation to broader yet related functions, and egestion in the form of poo or vomit. Although we might, as has been done for quite a long time, prioritize photo-autotrophs in the food chain of life, it would be a mistake to neglect the fundamental role that light plays in the entire holozoic (heterotrophic) phases of nutrition.
Let's begin by looking into the eyes.
Nutrition and Eyes
That eyes evolved without teleological purpose or ‘will’ hasn’t been in serious doubt since the earliest days of modern biology. In the Origin of Species, Darwin considered such ‘organs of extreme perfection’,
“…When it was first said that the sun stood still and the world turned round, the common sense of mankind declared the doctrine false; but the old saying of Vox populi, vox Dei, as every philosopher knows, cannot be trusted in science. Reason tells me, that if numerous gradations from a simple and imperfect eye to one complex and perfect can be shown to exist, each grade being useful to its possessor, as is certainly the case; if further, the eye ever varies and the variations be inherited, as is likewise certainly the case; and if such variations should be useful to any animal under changing conditions of life, then the difficulty of believing that a perfect and complex eye could be formed by natural selection, though insuperable by our imagination, should not be considered as subversive of the theory. How a nerve comes to be sensitive to light, hardly concerns us more than how life itself originated; but I may remark that, as some of the lowest organisms, in which nerves cannot be detected, are capable of perceiving light, it does not seem impossible that certain sensitive elements in their sarcode should become aggregated and developed into nerves, endowed with this special sensibility. (Darwin, C., Origin of Species, CH 6)
Perhaps due to an unfortunate passage preceding this quote, eyes received a lot of attention by those wishing to debunk the science on external grounds:
“To suppose that the eye with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I confess, absurd in the highest degree….”
Paleontology of the eye revealed that the vast divergence of eyes occurred in tandem with the incredible burst of life known as the Cambrian Radiation. Eyes emerged as a result of their role in the acquisition and processing of food, developing from particularly photo-sensitive cells to an incredible array of forms. These are either simple or compound eyes. Simple eyes have only one photoreceptive surface formed as a concave interior, and compound eyes, which consist of many independently functioning lenses laid out across a convex, exterior surface. As complicated as a simple vertebrate eye is, Dan-E Nilsson and Susan Pelger demonstrated in “A Pessimistic Estimate of the Time Required for an Eye to Evolve” (1994) that the number of transitions from a so-called ‘eye-spot’ to a refracting lensed eye could be accomplished in as few as several hundred thousand generations, a relative flash cosmologically speaking.
At stake in the evolution of eyes are so-called sensory tasks, that is to say what benefits that organ variation provides in terms of fitness relationships. While there are many ‘uses’ of an eye, Nilsson and Land suggest in Animal Eyes (2002) that visually guided predation most likely played a significant factor in the widespread development of eyes. In other words, eyes are useful to guide an organism to other organisms, to serve as food.
As heterotrophs, and falling under the domain eukaryote along with plants and fungi, and only eating other eukaryotes, we and other animals can only consume those of our own kind. An incredible diversity of living forms emerged from the diversity of envisioning other living beings as food. This optical organic cannibalism might be said to define life, whether partaken in gratitude according to the Japanese custom of Itadakimasu, or by disavowing participation in terms of a world presented as given under dominion. Thinking of humans as animals, seen through eyes effective for the kill, we might very well say apologetically, gomen’nasai.
There is however, a complication. At this stage, we have only considered one aspect of the nutritional system in terms of light, that of ingestion. It is not the end though. Before return to the prospect of guilt, shame, or even disgust that invites an apology, within animal consciousness, as seated in the CS-PCPT, we need to turn to an incredibly remarkable aspect of ‘the eye’ that falls outside of vision per se.
Although human eyes are remarkably free of hormones, more so than any other organ of the body, they nevertheless impact hormone cycling significantly by connecting light sensitive ganglion cells to the hypothalamus. We would suggest that this is more than incidental, and more tied to nutritional processes than generally appreciated. Physiological homeostasis also depends upon mechanisms of the eye, in addition to the obvious benefit that the organs have for targeting prey.
The best entry into the eye as a homeostatic regulator, comes in consideration of the impact that artificial light has on living beings. A wide yet voluminous range of scattered research has emerged in recent years on the subject, as natural luminous environments are ever increasingly degraded by artificial light. While there is much research on non-human animals, human medicine has been more comprehensive in this field.
“…Epidemiological and experimental studies in humans have shown that sleep disruption and exposure to artificial light at night (ALAN) are risks factors for the development of obesity (Obayashi et al. 2013; McFadden et al. 2014) and type 2 diabetes (Chaput et al. 2009; St‐Onge et al. 2012; Obayashi et al. 2014). Furthermore, animal studies have shown that exposure to ALAN increases body mass (Fonken et al. 2013a; Borniger et al. 2014; Aubrecht et al. 2015; Cho et al. 2015; Cissé et al., 2017), exacerbates inflammatory responses (Fonken et al. 2013, 2013a,b), alters food intake (Cissé et al. 2017), disrupts metabolism and circadian rhythms (Borniger et al. 2014; Kayaba et al. 2014), and changes insulin sensitivity (Coomans et al. 2013).
The strong relationship between circadian rhythms and metabolism is now well established, especially regarding the control of glucose homeostasis (La Fleur et al. 2001, Cailotto et al. 2005). Although most endogenous rhythms will continue to oscillate even without the presence of an environmental light/dark cycle; light is the most important environmental signal to entrain the intrinsic ~24 h (i.e., circadian) rhythms to the 24‐h rhythm of the rotation of the Earth. However, light can also be a potent circadian and endocrine disruptor when received at the wrong time of the day, that is, during the dark phase (Russart and Nelson 2018), causing alterations in the secretion of the hormones melatonin (Kalsbeek et al. 1999) and corticosterone (cortisol in humans) (Ishida et al. 2005), and changes in the expression of circadian genes in the hypothalamus (Best et al. 1999), pineal gland (Wu et al. 2008), adrenal (Ishida et al. 2005), and liver (Cailotto et al. 2009), all of them strongly involved in glucose metabolism…”
In “Blue light at night acutely impairs glucose tolerance and increases sugar intake in the diurnal rodent Arvicanthis ansorgei in a sex‐dependent manner, Anayanci Masís‐Vargas, David Hicks, Andries Kalsbeek, and Jorge Mendoza
Natural light varies in highly regular ways, defining eukaryotic habitat and by extension, the form and functioning of eukaryotic bodies as well. It is violently remarkable, that in mammals, the hypothalamus, an organ connecting the nervous system to the endocrine and exocrine systems, is itself connected to eukaryotic habitat by the mammalian eye, and specifically to photosensitive retinal ganglion cells. Remarkable, as the range of potential consciousness related to the species and temporally specific ocular perception of habitat, is also hosted by an organ, the eye, which significantly impacts a complex system of systems, intimately related to the prime fitness parameters of not only reproduction, but of the nutritive subcategories of digestion, absorption, and assimilation. We can look to other taxa as well but for simplicity, let’s stick with mammals for the moment.
We can break this down a bit further, without getting lost in the weeds. Endocrine systems are a ‘system of systems’, referring to the following set of axises. We’ll take an anthropomorphic perspective, exploring human systems as expressed by modern medicine, underscoring that similar relationships govern all animal life, albeit with potentially different particulars.
In humans, the TRH-TSH-T3/T4 hypothalamic–pituitary–thyroid axis governs the production of thyroid hormones, indispensable for growth, differentiation, reproduction and intelligence. The GnRH–LH/FSH hypothalamic–pituitary–gonadal axis governs production of gonadotropin-releasing hormones, controlling development, reproduction, and aging. The CRH - ACTH - cortisol hypothalamic–pituitary–adrenal axis, regulates reactions to stress and significant body processes, including digestion, the immune system, mood and emotions, sexuality, and energy storage and expenditure. The renin–angiotensin system (RAS), or renin–angiotensin–aldosterone system (RAAS), regulates fluid and electrolyte balance, along with blood pressure. Each of these subsystems exists in a feedback loop with the external environment, but in particular with the optical (image based) and luminous processing of the eye.
Finally, it is important to account for energy homeostasis in the body; the balance between intake of energy in the form of food resources and output, in the form of heat and work. The nervous system and compilation of endocrine systems are connected, so to speak, not simply ‘in’ the hypothalamus but in the complex surfaces of eyes. Photo-sensitive ganglion cells may be embedded at the farthest layer from incoming light, taking a less discernible stage than rods or cones, but they play an incredible role in connecting conscious (present), unconscious (repetitive) and automatic (inevitable) aspects of digestion.
Each of these component endocrine systems appears as a feedback loop, rather than as a static state. This means that as natural light changes about an animal, human or non-, the internal functioning of the animal is affected as an overall sequential process rather than episodic moment. When issues of nutrition and timing arise, say of seasonal eating, daily habits (of breakfast, second breakfast, lunch, tea, dinner, midnight snack etc…) or the courses in a meal from appetizer to dessert, the context is essentially the homeostasis of an organism within a complex cycle of life that had served a singular fitness, in lingering as one of earth’s many life forms.
Because animal eyes galvanize mechanisms for targeting and processing prey, along with mechanisms to aid the absorption, assimilation (into behaviors and functions that facilitate targeting/processing along with reproduction), they and the natural environments they relate to, in the manner they relate to elements within their ecological manifolds, govern nutrition. Measuring such light, as we have often emphasized, is essential to a deeper understanding of how food, as a process, relates to well-being.
Phenology, the timing of organic processes and activities, is incredibly important in this context. Time, we might say, is a function of its measurement. It is not necessarily the same for all animals, and the cycles of cesium atoms, the reference point for human exploration of the temporal-physical world, is not necessarily every animal’s guiding factor in how it relates to time. Natural light, with remarkable episodic moments occurring within an otherwise extreme regularity, subjected to variations in shape, quality, intensity and reach, establishes a hypothetical regulatory within the organism, complemented by perceptual nuances of the optical cannibalism (targeting and processing other living things) referred to above.
Despite the florid language, the concepts that emerge are quite simple. Cyclical natural luminous environments, are vital to nutrition. Eyes utilize light, enabling an organism to acquire and process food in a feedback loop (processing takes work, which requires food). This first aspect contends with episodic moments and opportunity. On the other hand, the light-based timing of an animal’s environment establishes dynamic homeostasis within it, crucial to transforming the episodic eating of food in the processes of an open system, an optimally consistent process that serves to constitute a species as such.
Who Am is what Who Am eats, but also ‘when', ‘how’, ‘what’ and ‘where' Who Am eats.
In this manner of thinking, the light based sequencing and timing of when, and under what conditions, an animal ‘eats’ is incredibly important. We say ‘optimally consistent’ in describing the physiology, sensory ecology, and integrative biology of an animal, because of course, ecologies and environments evolve and change. Yet there are limits to how far changes can be taken before the patterns or life are thrown off beyond recuperation. Light-based nutrition is vital to both the opportunistic functioning of animals, but also to the core existence from which ‘healthy’ changes can occur.
There are at least two distinct categories relevant for the timing of nutrition. One concerns the timing of the environment around an animal, that is to say changes to the environmental quality across the hours, days/night, months, seasons, and years, and to the changes present within the animal itself, in terms of life stages such as illness, hibernation or age in general. Understanding how a particular species exists with its food in either sense helps create a sense of how departures from the norm might impact its well being. Environmental light over time is important with respect of the former, and the specific photobiological processes (its ‘mental history’) and structures of each species and individual, again over time, matter.
Mindful Waste
Now, thinking broadly of nutrition again, we had not considered ‘waste’ or exedra yet. Yet it is important, as an integral part of the overall process of nutrition within an ‘open system’. Rather than considering waste as unrelated to fitness, which would be lazy, it is vital to consider either the ‘waste’ of organically generated heat or the elimination of excrement (along with the secretions of exocrine glands) in terms of the overall fitness of the animal. It seems in a sense too new a subject to deal with the photobiology of excrement adequately yet, but we can make a few confident remarks, especially with regard to ‘heat’.
Nearly half of ingested food in an animal is converted to heat. Yet this heat sets the context for work to be performed, creating thermal relationships that provide a context for action. This is true whether an animal is warm blooded or cold, the differences being in what specific contexts such heat it emitted and how it is regulated. There is also a corollary with light; one that the biophysicist Fritz Popp keenly marked out regarding mitochondrial photon emissions. Although “bio-photons” might be deemed unimportant, a random occurrence with no fitness relationship, Popp clearly demonstrated that such electromagnetic production establishes a coherent context within which the internal chemistry of an organism functions. ‘Waste’ establishes a context, and a means for regulation. It is returned to the environment in a feedback loop, conceptually similar to the internal functioning of endocrine sub-systems. Bioluminescence might also be considered in these terms, but as we are nearing the end of this long blog, we ought to sum up this last bit of blue-sky thinking, on the relationship of light to waste.
Waste, as part of a nutritional feedback loop, might be thought of as the content of consequences. Although we are used to thinking of animals, in terms of the eye, as predators, the complement of it is to remember that animals with eyes are also prey for others of a similar kind in the food chain. While we might turn our nose up at the sight of excrement, the fact of such disgust reminds us that there are threats within the nutritional feedback loop, of consumer and consumed.
And with this, we return to the concept of animal consciousness, that we had grounded in the CS-PCPT system in the last Inlightenment installment and referenced above. If in this installment, we have created a nutritious loop around an eye doubled by opportunistic targeting and homeostatic regulation, we can offer a means to depart from a very broadly accepted assumption that an implausible will to ‘survival’ dominates imagined purposefulness of animal mentality, whether human or non-human.
Exploring relationships of light to nutrition suggests something else; something of value for positive animal welfare outcomes related to the subject. Crediting animals with guilt, for optical cannibalism, shame, for failed opportunism or imbalance amidst change, and disgust, at the cyclical and threatening ambiguity of the predator prey relation, may seem like a fantastical anthropomorphic attribution. Yet these aspects, which the prospect of photo biologically conceived nutrition brings out, seem far more plausible than a teleological will of persistence or a decision-based biology that flies in the face of its founding concepts. As conscious entities subjected to homeostatic regulation, we can expect no less of animals.
In our efforts to integrate light within each of the Five Domains of Animal Welfare, we have discovered something specific in these observations. Nutrition invites consideration of diversity and inclusion into the subject of animal welfare, that often seems rather straightforward as pursuing something akin to ‘the interest’ of the animal. Instead, the overarching proposition of ‘nutrition’ in its five functional phases, lends credibility to a uniquely Japanese conception of animal welfare in terms of gratitude, humility, and pragmatism.
Itadekemasu, or ‘partaking in life’, is a familiar expression said before taking in a meal in Japan. When we eat, or are eaten for that matter, we partake in life in its most poignant scope. It is to be hoped that the pursuit of positive animal welfare through a Five Domains aligned practices, can lead to stronger communities because of it.
It is for the reader to decide.
To end at the beginning, our key take-aways are these four points.
Photobiology is all important to positive nutritional outcomes, and so to positive mental affect.
Environmental light governs the opportunistic and homeostatic aspects of nutrition, as neurological and endocrine systems function through ocularly governed feedback mechanisms.
Considering animals as open systems, connected to their environments as biological feedback loops, raises the importance of the five phases of nutrition taken for the mental well-being. Animal care specialists are encouraged to understand the internal and external photobiology of animals in their care, according to the phenological natural history of animals as well as their specific physiological, sensorial and integrative photo-biology.
Conceiving nutrition in this way, opens a path to a specifically Japanese concept of animal welfare, recognizing the ‘partaking in’ of life, rather than detached management of it. This will become important when we turn to questions of health in subsequent releases.
In the next installment of Inlightenment we will consider relationships of light and behavior, according to the Five Domains of Animal Welfare. Behavior widens the scope of consideration significantly, and we will explore categories as presented by Sara Shettleworth, in Cognition, Evolution, and Behavior, from a photobiological perspective.