Plenty of researches proves the existence of Mind- Body Connection.
A person's body and mind are dynamically interrelated that distress felt in one area of your well-being can have effects on another area. This means that our thoughts, feelings, beliefs, and attitudes can positively or negatively affect our biological functioning.
Psycho- Neuro-Immunology
Likewise, how we take care of our physical body - What we eat, how much we exercise, even our posture can impact our mental state positively or negatively thus exhibiting a complex interrelationship between our minds and bodies. A branch of science Psycho-Neuro-Immunology deals with understanding the bidirectional communication pathways between the brain and the immune system and the implications of this network for behavior are emphasized.