Negative emotions stimulate the production of proinflammatory chemicals that contribute to immune dysregulation, which predisposes us to a spectrum of conditions including aging, cardiovascular disease, osteoporosis, arthritis, type II diabetes, and cancer, and autoimmune disease. Higher social support is robustly associated with higher natural killer cell responsiveness in those under stress. Natural killer cells destroy viruses and cancer cells. Conversely, chronically abrasive close relationships are seen to decrease immune responsiveness. Solomon was right when he observed, as a man thinks in his heart, so he is. We could add, so is he physically.

Reference:

Kiecolt-Glaser JK, McGuire L, Robles TF, Glaser R.; Psychoneuro-immunology: Psychological influences on immune function & health. J Consult Clin Psychol. 2002 Jun; 70(3):537-47.

From the Sealy Center on Aging, Galveston, Texas comes a study that shows the benefits of positive emotions on cardiovascular health. This cross- sectional study included 2,564 Mexican Americans aged 65 or older living in one of the five Southwestern states. Increasing positive emotion score was significantly associated with both lower systolic blood pressure and diastolic blood pressure for individuals not on antihypertensive medication. After adjusting for relevant risk factors in those individuals taking blood pressure medication, increasing positive emotion score was significantly associated with lower diastolic score, but not the systolic. Each one-point increase in positive emotion score was associated with a 3% and 9% decreased odds of taking blood pressure medicine. 1  In order to decrease the risk of developing hypertension, we need to cultivate positive emotions. Let the peace of God rule in our hearts;… and be ye thankful.” Colossians 3:15.  Forgetting our own difficulties and troubles, let us praise God for an opportunity to live for the glory of His name. Let the fresh blessings of each day awaken praise in our hearts for those tokens of His loving care.  When you open your eyes in the morning, thank God that He has kept you through the night.  Thank Him for His peace in your heart. Morning, noon, and night, let gratitude ascend to heaven as a sweet perfume.” 2

References:
1. Ostir, GV, et al, Hypertension  in older adults and the role of positive emotions. 2006 Sep-Oct;68(5):727-33
2. White, Ellen, The Ministry of Healing. Review and Herald Publishers, p. 253