"Thus an insufficient supply of oxygen is received. The blood moves sluggishly. The waste, poisonous matter, which should be thrown off in the exhalations from the lungs, is retained, and the blood becomes impure. Not only the lungs, but the stomach, liver, and brain are affected. The skin becomes sallow, digestion is retarded; the heart is depressed; the brain is clouded; the thoughts are confused; gloom settles upon the spirits; the whole system becomes depressed and inactive, and peculiarly susceptible to disease. MH 273.1"
"A merry heart doeth good like a medicine: but a broken spirit drieth the bones."
Both passages discuss the connection between mental/emotional state and physical health. The EGW passage elaborates on the physical consequences of a 'broken spirit' or negative emotional state, aligning with the proverb's sentiment.