David McClelland -- a Behavioral Psychologist at Harvard -- performed a series of studies called "The Mother Theresa Effect" in the 1980s. He had several students watch a film about Mother Theresa's work helping the poor in India. After viewing the film, the students showed a significant rise in the protective antibody Salivary Immunoglobulin A (S-lgA) as compared to students who watched a neutral film. Dr. McClelland also noted that the students' S-lgA levels remained high for several hours after watching the film IF they were asked to recall a time they themselves had given or received love. The conclusion of the study was that thinking about love, giving and receiving love, strengthens the immune system.
A 2004 AA study done with data collected from Project Match found that recovering alcoholics who helped other addicts were more likely to stay sober than those who did not help others and 94 % of those who helped other recovering addicts noted a marked decrease in depression.
A 2005 study from the Longitudinal Study of Aging showed an in increase in longevity and happiness for those who volunteered at least once a week.
So this week, try to help one person every day. Hold the door for someone, give a homeless person a dollar, check in on a friend, send a card to an elderly relative, make a meal for your neighbor who's been working really hard, volunteer to watch your friend's child for an afternoon. You will not only be helping someone else, but as these studies show, you'll be helping your own health -- both emotional and physical.