Here are some health benefits of being kind to others,
Witnessing acts of kindness produces oxytocin, occasionally referred to as the ‘love hormone’ which aids in lowering blood pressure and improving our overall heart-health. Oxytocin also increases our self-esteem and optimism, which is extra helpful when we’re anxious or shy in a social situation. Natalie Angier, The New York Times
Energy
“About half of participants in one study reported that they feel stronger and more energetic after helping others; many also reported feeling calmer and less depressed, with increased feelings of self-worth” Christine Carter, UC Berkeley, Greater Good Science Center
Lifespan
“People who volunteer tend to experience fewer aches and pains. Giving help to others protects overall health twice as much as aspirin protects against heart disease. .” Christine Carter, Author, “Raising Happiness; In Pursuit of Joyful Kids and Happier Parents
Depression
Stephen Post of Case Western Reserve University School of Medicine found that when we give of ourselves, everything from life satisfaction to self-realization and physical health is significantly improved. Mortality is delayed, depression is reduced and well-being and good fortune are increased.
Another study found that we can become happier, by reflecting once a week, on what kind acts you have completed each week. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1820947/)