Intermittent drinking, oxytocin and human health
Introduction
Stress, broadly defined as a real or perceived threat to homeostasis, activates neural circuits that alter the body’s physiology and behaviour to ensure survival and well-being. Physical stressors are real threats that create signals within the internal environment that communicate deviations from homeostasis to the brain. In contrast, perceived threats or psychogenic stressors create signals that arise within the brain itself as it interprets stimuli in the external environment as potential insults [1]. Both type of stress factors activate allostatic systems, including the sympathetic nervous system and hypothalamic circuits, leading to stressful and even aggressive behaviour [2]. Starvation, infection, dehydration, violence and climate are ancient stressors producing severe danger to the body and have therefore shaped ultimate survival function producing proximate homeostatic feelings to induce behaviour at service of the ultimate purpose [3]. Perhaps the best example is humans crying. The ultimate explanation of crying is that it elicits care and defence from mothers and other care-givers; if infants do not cry when in need of assistance, it will be less likely to survive. Proximate explanations include both the external triggers of crying, for example physical separation from the caregiver, cold, or a lack of food, and also the internal mechanisms, such as the limbic system and the endogenous opioids involved in the cessation of crying. These are proximate explanations because they describe the immediate causal triggers of crying [4]. In this context, the ultimate explanation for hunger is to signal the body for possible starvation and death. The proximate value of hunger is that it leads to eating, although eating is also stimulated by looking at, smelling of and thinking in food, which are therefore all proximate causes of eating [5]. This so-called thought-shaped fusion can be so strong that individuals can gain weight just looking at food [6]. Food deficiency as a stress factor activates a complex systemic response, which should lead to gluconeogenesis, changes in energy distribution and spontaneous physical activity [7], [8]. Starvation may induce a certain level of aggressive behaviour, which should be considered adaptive when hunting big game or when suffering from a lack of high-energy nutrients [9], [10], whereas food sharing behaviour is more beneficious once the animal has been hunted (see [11] and the references herein).
Overall, stress responses activate the sympathetic nervous system, together with the HPA axis exerting a range of effects in benefit of solving the homeostatic disturbance as fast as possible. Of all stress factors dehydration occupies a special place in animal evolution. It seems to be the only homeostatic disturbance leading to attenuation of stress axis responses, decrease of fear feelings, anxiety and aggressive behaviour [12]. Drinking, caused by regulatory thirst, could be considered proximate behaviour at service of preventing dehydration, an ultimate purpose [13]. Nevertheless it is regulatory or also physiological drinking, which is regulated by oxytocin and therefore drinking could also stand at the service of another ultimate purpose; bonding. These are the reasons which made us formulate our hypothesis; Could bulk drinking recover human health, trust and mental well being? In this hypothesis “bulk drinking” is defined as non-frequent drinking up to satiety and only when thirsty; like drinking visiting a waterhole.
Section snippets
Thirst, trust, oxytocin and bonding
Animals drink up to satiety every time they drink, just as infants do. So infants and animals “suffer” real thirst (regulatory/physiological thirst, 14) based on hypernatremia, hypovolemia and/or hyperosmolality [15], [16] and these conditions induce increased oxytocin signalling (Olszewski, 2010). Oxytocin has numerous effects on multiple physiological mechanisms and oxytocin influences behaviour significantly (see below). The mentioned up to satiety-drinking behaviour of infants every time
People at search for oxytocin; the pandemic use of oxytocinergic drugs and the need for new interventions; our hypothesis
Prosocial and empathogenic behaviour depend on endogenous oxytocin systems, which might be disturbed in people engaging in drug use and addiction [40]. It has been shown recently that the rate of parental bonding and attachment in childhood is directly related with adult psychosocial behaviour including drug use and abuse [41]. It might even be so that drug users become “bonded” to their drugs and the environmental triggers related with the use of drugs [40].
On the other hand, stable social
Discussion
Bulk drinking, earlier defined as non-frequent drinking up to satiety, resembles the animal behaviour at waterholes. The majority of herbivores travel from waterhole to waterhole to cover their fluid needs and will drink up to satiety every time they visit this or another waterhole [58]. Animals at the waterhole show low level of anxiety and fear and this behaviour is probably caused by dehydration-increased oxytocin signalling [12].
More specifically, numerous studies have demonstrated that
Conflict of interest
We state that both authors do not have any conflict of interest.
References (72)
- et al.
Asymmetry between salivary cortisol and alpha-amylase reactivity to stress: relation to aggressive behavior in adolescents
Psychoneuroendocrinology
(2006) - et al.
The Darwinian concept of stress: benefits of allostasis and costs of allostatic load and the trade-offs in health and disease
Neurosci Biobehav Rev
(2005) - et al.
Stimulus-induced eating when satiated
Physiol Behav
(1989) - et al.
“Just looking at food makes me gain weight”: experimental induction of thought-shape fusion in eating-disordered and non-eating-disordered women
Behav Res Ther
(2008) - et al.
The evolution of violence in men: the function of central cholesterol and serotonin
Prog Neuropsychopharmacol Biol Psychiatry
(2009) - et al.
Changes in social instigation- and food restriction-induced aggressive behaviors and hippocampal 5HT1B mRNA receptor expression in male mice from early weaning
Behav Brain Res
(2008) Physical inactivity is a disease synonymous for a non-permissive brain disorder
Med Hypotheses
(2011)Thirst and hydration: physiology and consequences of dysfunction
Physiol Behav
(2010)- et al.
Oxytocin as feeding inhibitor: maintaining homeostasis in consummatory behavior
Pharmacol Biochem Behav
(2010) - et al.
Oxytocin decreases corticosterone and nociception and increases motor activity in OVX rats
Maturitas
(2005)
Deconstructing sociality, social evolution and relevant nonapeptide functions
Psychoneuroendocrinology
Neuropeptides and non-human primate social deficits associated with pathogenic rearing experience
Int J Dev Neurosci
Breaking the loop: oxytocin as a potential treatment for drug addiction
Horm Behav
The quality of parent/child relationships in adolescence is associated with poor adult psychosocial adjustment
J Adolesc
Protective factors of substance use in youth subcultures
Addict Behav
Family management of cannabis in adolescent
Arch Pediatr
On the origin of allostasis and stress-induced pathology in farm animals: celebrating Darwin’s legacy
Vet J
Oxytocin action in the ventral tegmental area affects sucrose intake
Brain Res
The treatment of hyponatremia
Semin Nephrol
Adverse childhood experiences, allostasis, allostatic load, and age-related disease
Physiol Behav
The neurobiology of stress management
Neuro Endocrinol Lett
Evolutionary theory and the ultimate–proximate distinction in the human behavioral sciences
Perspect Psychol Sci
The brain’s supply and demand in obesity
Front Neuroenerg
Behavioral responses to orexin, orexin receptor gene expression, and spontaneous physical activity contribute to individual sensitivity to obesity
Am J Physiol Endocrinol Metab
Human behavioral ecology: current research and future prospects
Behav Ecol
Hydration state controls stress responsiveness and social behavior
J Neurosci
Water, hydration and health
Nutr Rev
Oxytocin and vasopressin: social neuropeptides with complex neuromodulatory functions
Neurology
Molecular, immunohistochemical, and pharmacological evidence of oxytocin’s role as inhibitor of carbohydrate but not fat intake
Endocrinology
The neurobiological link between compassion and love
Med Sci Monit
A neuro-endocrine-immune symphony
J Neuroendocrinol
Anti-inflammatory effect of oxytocin in rat myocardial infarction
Basic Res Cardiol
Effect of petting a dog on immune system function 1
Psychol Rep
The oxytocin receptor system: structure, function, and regulation
Physiol Rev
The neurobiology of pair bonding: insights from a socially monogamous rodent
Front Neuroendocrinol
Love and attachment: the psychobiology of social bonding
CNS Spectr
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