The simple act of deciding to be happier and focus on the positive will improve your health. Just as negative emotions can weaken the body's resistance level, positive emotions can
give us strength, or at least allow our bodies to function normally. Therefore, the simple act of deciding to be happier and focus on the positive will improve your health.
In fact, the phenomenon of your thoughts affecting your physical health is so strong that all medical studies have to be designed with it in mind. Researchers call this 'the placebo effect.'
Many people believe that the term 'placebo effect' means that the effect is only imagined - that it is not real. But this couldn't be further from the truth. Medical studies have to include a control group - people who receive placebos instead of the medicine being studied - because the simple act of people making the decision to take action to improve their health leads to measurable physical improvement in their condition.
To determine the effects of a particular medicine, researchers have to measure the change in the group who underwent therapy and subtract out the amount of change seen in the placebo group. Otherwise, there is no way to know whether a particular treatment was beneficial or whether it was merely the change in attitude in the study subjects that made the difference. In many instances, the placebo effect turns out to be stronger than the treatment itself!
The point is that if you want to have a healthy body you also have to have healthy thoughts and emotions. Just as it is important to avoid toxic chemicals, it is also necessary to avoid toxic thoughts to enjoy optimal health.