The nutrient plays an important role in proper brain functioning as it controls the
HPA axis, which is the center of the body's stress response system.
Some experimental animal studies also reported that the NPS/NPSR system is associated with the modulation of fear conditioning and
HPA axis, with stress responses and anxiolytic effects (7-9).
HPA axis stimulation leads to a cascade of responses resulting in the release of adrenaline and noradrenaline from adrenal gland.
Additionally, a lower proportion of subjects in the Impoyz Cream group (12.5%) experienced
HPA axis suppression compared to those in the Temovate Cream group (36.4%), although this did not reach statistical significance (P=0.086).
The
HPA axis connects the central nervous and endocrine systems of the body.
(15,16) Therefore, although researchers have speculated about many factors, such as time, individual differences, and stress-induced long-term sensitization or desensitization of the
HPA axis, (17) there appears to be no clear primary determinant on the outcome in those studies.
(49,56) Hyperactivity of the
HPA axis and inflammation can alter neurogenesis and brain architecture which increases the probability of depression occurrence and relapse.
Various publications on the available methods to assess adrenal fatigue and the hypothalamic-pituitary-adrenal (HPA) axis report contradictory results, and in most cases the most appropriate methodology to assess the
HPA axis was not utilised.
The
HPA axis is the human body's central stress response system.
Activity on the
HPA axis is typically indicative of a response to stress or rhythmicity diurnal, however factors such as food intake can also lead to cortisol secretion (Rosmond et al., 2000).
"It is likely that at least some of the significant improvements in both
HPA axis functioning as exemplified by the CAR as well as neuroimmunologic functioning as exemplified by increases in BDNF levels and alterations in cytokines were due to the intensive meditation practice involved in this retreat," says corresponding author Dr Baruch Rael Cahn (University of Southern California, USA).