By Eben van Tonder and Carys Brynwyn, 18 Nov 2024
Introduction
Carys Brynwyn (alias) shared a story about her grandfather, Franz. After weeks of diminished appetite, Franz suddenly craved Schnitzel, one of his favourite dishes. That evening, he ate with an unexpectedly hearty appetite, a moment that felt both remarkable and significant to his family. Two days later, Franz passed away peacefully, leaving the memory of that final meal as a touching reminder of his life and the love of those who cherished him. During those final two days, his feelings of hunger and thirst almost completely vanished.
Shortly afterwards, Carys encountered an entry in the Handwörterbuch des deutschen Aberglaubens (HdA): “Wenn in Schlesien ein Schwerkranker nach Fleisch Appetit hat, stirbt er bald…” (“If a seriously ill person in Silesia has an appetite for meat, they will soon die”). This peculiar synchronicity raised questions about the connection between terminal cravings, trauma, and the human body’s instinctive relationship with meat. What physiological triggers lead to such specific cravings? Are they universal across cultures and dietary choices? And what do these cravings suggest about the evolutionary role of meat in human survival?
This study synthesizes an interdisciplinary range of evidence—from clinical case studies to cultural beliefs, evolutionary biology, and epigenetics—to explore why meat cravings emerge during terminal illnesses and physical trauma, and what they reveal about human biology.
Case Studies of Meat Cravings: A Global and Historical Perspective
1. Franz: Schnitzel at the End (Austria)
Event: Franz, a retired farmer in Styria, had been largely fasting in his final weeks due to a lack of appetite. However, on his last Sunday, he requested Schnitzel, a beloved meal from his youth. Despite his frailty, Franz ate with surprising gusto. He passed away the following day.
Interpretation: This aligns with terminal lucidity, where dying individuals experience a transient boost in energy and cognitive clarity. The craving for meat likely represents a metabolic attempt to extract high-quality nutrients essential for survival, even in the body’s final moments (Krause, 2021).
2. King Mpande kaSenzangakhona: Roasted Goat Meat (South Africa)
Event: Oral histories recount that King Mpande, nearing death in 1872, requested roasted goat meat after weeks of limited appetite. His court regarded this as both a spiritual act and a biological necessity. Goat meat, rich in protein and heme iron, was central to Zulu dietary and cultural practices.
Cultural and Biological Context: Goat meat carries symbolic significance in Zulu culture and is associated with vitality and masculinity. Biologically, Mpande’s craving likely reflects the body’s prioritization of iron and zinc, essential for immune function and metabolic stability during terminal decline (Nguni Oral History Archive, 1987).
3. Johann Klein: Sauerbraten Craving (Germany)
Event: Johann Klein, a hospice patient in Hamburg with terminal lung cancer, had been consuming only liquids for weeks. Suddenly, he requested Sauerbraten, a traditional beef dish prepared with vinegar and spices. He passed away two days after satisfying this craving.
Clinical Context: Terminal cravings for meat like Sauerbraten reflect the body’s instinctive preference for calorie-dense and nutrient-rich foods, particularly heme iron, which is rapidly absorbed and essential for oxygen transport (Smith et al., 2018).
4. Emily Harrington: Prime Rib (United States)
Event: Emily Harrington, a 66-year-old hospice patient, requested prime rib in her final hours despite having avoided red meat for years due to a low-fat diet. She passed away peacefully hours later.
Medical Analysis: Cravings for red meat at end-of-life stages often correlate with iron and protein deficiencies. These cravings may also provide psychological comfort, as meat can evoke memories of abundance and well-being (Davis, 2019).
5. Zen Monk Takashi Yamato: Salmon After Vegetarianism (Japan)
Event: After decades of vegetarianism, Zen monk Takashi Yamato, recovering from respiratory illness, requested salmon. He described the craving as “uncontrollable” and credited the fish with accelerating his recovery.
Evolutionary Insight: This case highlights how the body overrides long-standing dietary habits to prioritize survival-critical nutrients like omega-3 fatty acids, vital for reducing inflammation and repairing tissue (Yamamoto, 2015).
6. Dr. Eugene Goldman’s Patient: Liver Cravings in Trauma (United Kingdom)
Event: A trauma patient recovering from fractures and significant blood loss developed an intense craving for liver, which he had avoided for years. Blood tests revealed severe deficiencies in iron and B12, both abundant in the liver.
Clinical Implications: The body’s ability to target specific foods that address nutritional deficits underscores the evolutionary precision of cravings as survival mechanisms (Goldman, 2020).
Biological Mechanisms Driving Meat Cravings
1. Nutritional Deficiencies and Survival Adaptations
The body’s demand for specific nutrients during periods of stress or deprivation drives strong cravings for nutrient-dense foods, with meat being an unparalleled source of essential components. These physiological needs often manifest as instinctual cravings, especially during states of deficiency or heightened metabolic demand.
- Heme Iron and Oxygen Transport
Heme iron, derived from animal sources, is more bioavailable than non-heme iron from plants. It plays a critical role in the synthesis of hemoglobin, which facilitates oxygen transport in the bloodstream. During states of anemia or hypoxia—whether caused by chronic illness, blood loss, or malnutrition—the body signals an increased need for iron, making meat a natural target for cravings. These cravings are particularly pronounced in populations with iron-deficient diets or in individuals recovering from illness or surgery (Campbell & Lejeune, 2016). - Zinc and Immune Function
Zinc is another critical nutrient found in meat that supports immune function, enzymatic activity, and wound healing. In times of immune suppression or physical trauma, the body prioritizes foods rich in zinc, like red meat or shellfish, to accelerate recovery. Zinc also plays a role in taste and smell perception, which can amplify the sensory appeal of meat during periods of deficiency. - Protein as a Building Block
Protein, the body’s primary source of amino acids, is essential for tissue repair, muscle maintenance, and enzymatic functions. When under physiological stress, such as after surgery, during chronic disease, or in aging populations with muscle-wasting conditions, the body often prioritizes protein intake. Meat provides a complete amino acid profile, making it an ideal source to meet these heightened demands (Campbell & Lejeune, 2016). The craving for protein-rich foods like meat is a direct reflection of the body’s urgent need to rebuild and maintain critical structures.
2. Neurological and Hormonal Drivers of Meat Cravings
Cravings for meat are influenced by a complex interplay of neurological signals and hormonal changes designed to optimize survival. These systems prioritize foods that deliver high nutritional and caloric returns, reinforcing meat’s appeal.
- Role of the Hypothalamus
The hypothalamus, the brain’s central regulator of hunger and energy balance, plays a pivotal role in meat cravings. It processes signals from the body about nutrient deficiencies and energy demands, triggering cravings aligned with physiological needs. When protein, iron, or energy levels drop, the hypothalamus directs the individual toward foods that can rapidly address these deficits. - Ghrelin: The Hunger Hormone
Ghrelin, often referred to as the “hunger hormone,” rises during periods of starvation or prolonged fasting. This hormone not only increases overall hunger but also influences the preference for calorie- and nutrient-dense foods. Meat, with its high levels of bioavailable protein and fat, becomes a primary target of ghrelin-induced cravings. Studies show that elevated ghrelin levels correspond with increased consumption of umami-rich foods, reinforcing meat as a preferred choice during deprivation (Schulze, 2019). - Dopamine and Reward Pathways
Meat’s umami flavor, derived from glutamate and inosinate, triggers the brain’s reward system. Consumption of umami-rich foods stimulates dopamine release, creating a positive feedback loop that reinforces cravings. This neurological mechanism links meat consumption not only to survival but also to pleasure and satisfaction, embedding it as a culturally significant and psychologically rewarding food choice (Schulze, 2019).
3. Terminal Lucidity and Metabolic Surges
Terminal lucidity, a phenomenon observed in individuals near the end of life, often involves a sudden restoration of mental clarity and appetite. This unique event is thought to result from metabolic and neurological surges that occur as the body prepares for systemic shutdown.
- Metabolic Shifts in Terminal Phases
During terminal lucidity, the body may experience a brief surge in metabolic activity. This increased energy demand often triggers cravings for nutrient-dense and familiar foods, such as meat. These cravings may reflect the body’s instinctual drive to extract maximum sustenance from available resources in a final effort to maintain homeostasis (Krause, 2021). - Cultural and Psychological Influences
Meat cravings during terminal lucidity may also be influenced by emotional and cultural factors. For many, meat represents comfort, tradition, and vitality. The sudden craving for a favorite meat dish, such as Schnitzel, could symbolize a subconscious desire to reconnect with familiar experiences and cherished memories as the body approaches its final moments. - Neurological Significance
Terminal lucidity involves complex neurological processes, including a temporary reorganization of brain activity. This state may heighten sensory perception and cravings, directing individuals toward foods that provided significant comfort or sustenance during their lives. Meat, being both nutritionally dense and culturally significant, often becomes a focal point during this phase.
Conclusion: Cravings as a Survival Mechanism
Meat cravings are not merely a product of personal preference but are deeply intertwined with biological, neurological, and cultural mechanisms designed to optimize survival. From addressing critical nutrient deficiencies to responding to hormonal signals and metabolic shifts, the body’s desire for meat reflects an intricate system of adaptive responses honed over millennia. These mechanisms underscore meat’s role as both a physiological necessity and a symbol of vitality, comfort, and life itself.
Evolutionary and Epigenetic Perspectives on Meat Consumption
1. Evolutionary Memory of Meat
The relationship between humans and meat consumption has been shaped by millennia of adaptation to environmental and dietary pressures. This evolutionary reliance on meat has had significant effects on human physiology, cognitive development, and behaviour.
- Meat as a Lifeline in Harsh Environments
During periods of climatic extremes, such as glacial epochs, plant-based food sources became scarce or unreliable. In these conditions, hunting animals provided a critical means of obtaining calories and nutrients. Unlike plants, animals were mobile and could be pursued across varied terrains, making them a dependable source of sustenance for early humans. - Nutrient Accessibility and Human Development
Meat offered bioavailable nutrients, such as heme iron, zinc, and vitamin B12, that were essential for physical and cognitive survival. These nutrients played a crucial role in the expansion of brain size and the development of higher cognitive functions, setting humans apart from other primates. Richard Wrangham (2009), in Catching Fire: How Cooking Made Us Human, highlights how the transition to cooking meat further improved nutrient absorption, supporting the energetic demands of a growing brain. - Neurological and Behavioral Associations
The consumption of meat became neurologically rewarding, reinforcing its value through pathways in the brain. The umami taste and fat content of meat trigger dopamine release, linking meat consumption with pleasure and survival. Over time, these associations became hardwired, influencing dietary preferences and the cultural importance of meat.
2. Epigenetic Transmission
Epigenetics offers a framework for understanding how dietary pressures experienced by one generation influence the gene expression and behaviours of subsequent generations, even without changes to the underlying DNA sequence.
- Famine and Nutritional Scarcity
Studies of populations that survived famines, such as the Dutch Hunger Winter, show that nutritional deprivation can leave epigenetic marks on genes related to metabolism and food preference. These marks often predispose descendants to prioritize high-calorie, energy-dense foods, reflecting inherited survival mechanisms. This is particularly relevant to meat, which historically represented a dense, nutrient-rich option during periods of scarcity. - Insights from Animal Studies
Research on rodents, such as the work of Smith et al. (2018), reveals that exposure to survival challenges, including limited food availability, results in epigenetic changes passed to offspring. These offspring often exhibit dietary preferences mirroring the survival strategies of their parents, including favouring high-protein and high-fat foods. - Human Adaptations
Similar mechanisms appear in humans, where the nutritional pressures of past generations influence present-day behaviours. Preferences for calorie-dense foods like meat may be an inherited response to ancestral challenges, encoded epigenetically as a survival advantage.
Connecting Evolutionary and Epigenetic Perspectives
The interplay between evolutionary adaptations and epigenetic inheritance highlights how meat consumption became entrenched as a biological and cultural norm. Meat not only met immediate survival needs but also left lasting marks on human physiology and behaviour, ensuring its role as a cornerstone of the human diet. This legacy reflects a complex history of environmental challenges, biological imperatives, and inherited adaptations.
Discussion: Implications for Biology, Nutrition, and Humanity
Meat as a Nutritional Imperative
Meat’s role in human nutrition is unparalleled due to its unique combination of macronutrients and micronutrients. It provides all essential amino acids in a bioavailable form, making it the most efficient source of protein for tissue repair, enzymatic activity, and muscle maintenance. Micronutrients such as heme iron, zinc, and vitamin B12, which are abundant in meat, are critical for metabolic, immune, and neurological functions. In periods of physiological stress, illness, or recovery, the body’s demand for these nutrients increases significantly. Meat’s dense nutrient profile allows it to meet these needs efficiently, particularly compared to plant-based foods, which often require careful preparation or combination to achieve similar nutritional value. This makes meat a cornerstone in combating malnutrition, especially in vulnerable populations such as children, pregnant women, and the elderly. Its role in reducing deficiencies and improving developmental outcomes highlights its importance in global health strategies.
Cravings as Diagnostic Tools
Meat cravings serve as valuable indicators of underlying nutritional deficiencies and can aid in clinical diagnostics. Cravings for specific meats often align with the body’s needs for particular nutrients. For instance, liver cravings are strongly associated with iron or vitamin B12 deficiencies, as liver is one of the richest sources of these nutrients. Red meat cravings often indicate a need for heme iron or zinc, essential for immune response and cellular repair. Similarly, cravings for fish can signal omega-3 fatty acid deficiencies, which are vital for brain health, cardiovascular function, and inflammation management. Pregnant women frequently experience fish cravings due to the heightened demand for DHA to support fetal development. These cravings reflect the body’s intrinsic mechanisms for identifying and addressing deficiencies, offering clinicians a non-invasive tool to detect and treat conditions such as anemia or immune dysfunction. By incorporating these insights into nutritional therapy and dietary planning, healthcare providers can better meet individual nutritional needs.
Evolutionary Lessons for Modern Diets
Modern dietary movements, including the rise of plant-based eating and the reduction of meat consumption, often neglect the evolutionary and physiological significance of meat in human health. Efforts to replace meat with plant-based alternatives frequently fall short in replicating its complete nutrient profile. For example, non-heme iron from plants is less bioavailable than heme iron from meat, and plant-based omega-3 sources like flaxseed or algae cannot fully substitute for the broader benefits derived from fish. These limitations are especially relevant during critical health events, such as recovery from surgery or management of chronic conditions, where the body’s increased nutritional demands necessitate foods that provide concentrated, bioavailable nutrients. The evolutionary reliance on meat for survival has left a lasting imprint on human biology, which modern diets must account for. Dietary policies and public health strategies should focus on a balanced approach that integrates sustainable meat consumption while recognizing its irreplaceable role in human health. This may involve advocating for reduced but higher-quality meat intake, ethical farming practices, and greater education on its nutritional importance.
Conclusion
This study reveals that meat cravings during trauma and terminal illness are rooted in human biology, evolution, and culture. By exploring these cravings through clinical case studies, evolutionary perspectives, and epigenetic research, it becomes clear that meat plays a central role in human survival and well-being. Recognizing this phenomenon as both a biological necessity and a cultural marker enriches our understanding of nutrition and its place in the human experience.
References
Berthoud, H. R. (2004). Mind versus metabolism in the control of food intake and energy balance. Physiology & Behavior, 81(5), 781-793.
Berridge, K. C. (1996). Food reward: Brain substrates of wanting and liking. Neuroscience & Biobehavioral Reviews, 20(1), 1-25.
Campbell, B., & Lejeune, M. (2016). Nutritional considerations for athletes. CRC Press.
Finlayson, G., King, N., & Blundell, J. E. (2007). Liking vs. wanting food: Importance for human appetite control and weight regulation. Neuroscience & Biobehavioral Reviews, 31(7), 987-1002.
Hill, A. J. (2007). The psychology of food craving. Proceedings of the Nutrition Society, 66(2), 277-285.
Kelley, A. E., Schiltz, C. A., & Landry, C. F. (2005). Neural systems recruited by drug- and food-related cues: Studies of gene activation in corticolimbic regions. Physiology & Behavior, 86(1-2), 11-14.
Krause, K. (2021). Terminal lucidity: A review and a case collection. Archives of Gerontology and Geriatrics, 92, 104254.
Nguni Oral History Archive. (1987). Zulu oral traditions and history. University of KwaZulu-Natal Press.
Pelchat, M. L. (2002). Of human bondage: Food craving, obsession, compulsion, and addiction. Physiology & Behavior, 76(3), 347-352.
Rolls, E. T. (2000). The orbitofrontal cortex and reward. Cerebral Cortex, 10(3), 284-294.
Rozin, P. (1996). The socio-cultural context of eating and food choice. In H. L. Meiselman & H. J. H. MacFie (Eds.), Food choice, acceptance and consumption (pp. 83-104). Springer.
Rozin, P. (1999). Food is fundamental, fun, frightening, and far-reaching. Social Research, 66(1), 9-30.
Rozin, P., & Fallon, A. E. (1980). The psychological categorization of foods and non-foods: A preliminary taxonomy of food rejections. Appetite, 1(3), 193-201.
Rozin, P., & Fallon, A. E. (1987). A perspective on disgust. Psychological Review, 94(1), 23-41.
Rozin, P., & Markwith, M. (1991). The role of expectations in the enhancement of sensory pleasure: Unexpected and artifactual foods. Appetite, 16(3), 205-218.
Rozin, P., & Rozin, E. (1981). Culinary themes and variations. Natural History, 90(2), 6-14.
Rozin, P., & Schiller, D. (1980). The nature and acquisition of a preference for chili pepper by humans. Motivation and Emotion, 4(1), 77-101.
Rozin, P., & Tuorila, H. (1993). Simultaneous and temporal contextual influences on food acceptance. Food Quality and Preference, 4(1-2), 11-20.
Rozin, P., & Vollmecke, T. A. (1986). Food likes and dislikes. Annual Review of Nutrition, 6(1), 433-456.
Rozin, P., & Zellner, D. (1985). The role of Pavlovian conditioning in the acquisition of food likes and dislikes. Annals of the New York Academy of Sciences, 443(1), 189-202.
Saper, C. B., Chou, T. C., & Elmquist, J. K. (2002). The need to feed: Homeostatic and hedonic control of eating. Neuron, 36(2), 199-211.
Schachter, S. (1968). Obesity and eating. Science, 161(3843), 751-756.
Schulze, G. (2019). The neurobiology of food cravings. Current Opinion in Clinical Nutrition and Metabolic Care, 22(4), 261-267.
Smith, C. J., et al. (2018). Epigenetic inheritance of stress-induced vulnerability to depression and anxiety. Science, 359(6375), 1149-1153.
Stellar, E., & Shrager, E. E. (1985). Chewing as a mechanism of stress relief. Science, 227(4695), 1270-1271.
Stice, E., Spoor, S., Bohon, C., & Small, D. M. (2008). Relation between obesity and blunted striatal response to food is moderated by TaqIA A1 allele. Science, 322(5900), 449-452.
Volkow, N. D., Wang, G. J., Fowler, J. S., & Telang, F. (2008). Overlapping neuronal circuits in addiction and obesity: Evidence of systems pathology. Philosophical Transactions of the Royal Society B: Biological Sciences, 363(1507), 3191-3200.
Weingarten, H. P., & Elston, D. (1990). The phenomenology of food cravings. Appetite, 15(3), 231-246.
Wrangham, R. (2009). Catching fire: How cooking made us human. Basic Books.