No, the mind can have a significant effect on the body. For example this webmd article on placebo cites studies where what the participant was told about a pill

No, the mind can have a significant effect on the body. For example this webmd article on placebo cites studies where what the participant was told about a pill (stimulant vs sleep aid) effected heart rate, blood pressure and reaction time in opposite directions. https://www.webmd.com/pain-management/what-is-the-placebo-effect https://www.webmd.com/pain-management/what-is-the-placebo-ef...