The influences of diet and exercise on mental health through hormesis

Abstract

It is likely that the capacity of the brain to remain healthy during aging depends upon its ability to adapt and nurture in response to environmental challenges. In these terms, main principles involved in hormesis can be also applied to understand relationships at a higher level of complexity such as those existing between the CNS and the environment. This review emphasizes the ability of diet, exercise, and other lifestyle adaptations to modulate brain function. Exercise and diet are discussed in relationship to their aptitude to impact systems that sustain synaptic plasticity and mental health, and are therefore important for combating the effects of aging. Mechanisms that interface energy metabolism and synaptic plasticity are discussed, as these are the frameworks for the actions of cellular stress on cognitive function. In particular, neurotrophins are emerging as main factors in the equation that may connect lifestyle factors and mental health.

Fig. 1

Diagram illustrating a general mechanism by which diet, exercise, and other environmental challenges can affect mental health. It is postulated that control of cellular energy balance is a confluent point for the effects of environmental factors. Energy balance via interactions with BDNF, in conjunction with other factors, can modulate synaptic plasticity underlying cognitive processes.

Fig. 2

Proteomic analysis of hippocampal proteins influenced by exercise. Two-dimensional gel electrophoresis maps of the hippocampus from sedentary (A, C) and exercised (B, D) rats showing the location of protein spots. C and D are high magnifications of A and B, respectively. (E) Mass spectrometry analysis was used to identify specific protein spots, and revealed that a total of approximately 90% of the proteins identified are associated with energy metabolism or synaptic plasticity (Ding et al., Eur. J. Neurosci., 24 (2006) 1265.

Fig. 3

Diagram exemplifying the interaction between the gut and the brain on mental health. It is postulated that this interaction is accomplished by involving molecular and cellular mechanisms associated with energy metabolism. As discussed in the text, many molecular mechanisms attributed exclusively to the gut have been found to occur in the brain. For example, IGF-1 and insulin that are produced in the periphery can enter the CNS and modify brain function.