That is what a researcher at the University of Nebraska in the United States wrote after reviewing a number of studies on health.
يَقُولُ ٱلْكِتَابُ ٱلْمُقَدَّسُ :‏ « اَلْقَلْبُ ٱلْفَرْحَانُ دَوَاءٌ نَاجِعٌ » .‏