I write a lot about the business and community benefits of employee volunteering and giving, and with each passing year I see more companies interested in the bottom-line value of a culture of social purpose. No matter what your company’s business, the business of giving back can supplement any organizational mission. When social impact is baked into your company’s DNA, employees are drawn to join your company, they work more effectively, and they stay.

The connection between employee volunteering and employee engagement is a clear, vibrant line that is increasingly accepted in corporate corridors. But when business leaders examine the ROI of employee volunteering and giving programs, there’s one line item which is often overlooked: the health benefits of volunteering.

Yes. Not only can your volunteer program improve recruitment, engagement, productivity and retention – it can also decrease the costs associated with employee health and well-being.

Reams of data have long proven the correlation between volunteering and positive health outcomes. A study by the Corporation for National and Community Service found that the benefits include greater longevity, lower rates of depression, a lower incidence of heart disease and higher functional ability. One of the secrets behind the health benefits of volunteering may have to do with increasing levels of oxytocin, a neurochemical associated with trust and feelings of closeness. More oxytocin leads to less stress and more feelings of calm.

Amongst the different age groups, older volunteers seem to derive the most benefit, perhaps because volunteering provides physical and social activity and a sense of purpose, and researchers suspect that volunteering may allow people to maintain their independence as they grow older.

Here are some of the findings of the study:

  • People with chronic pain experienced a reduction in pain intensity and less disability when they started to work as peer volunteers for others suffering from chronic pain.
  • People who volunteer after a heart attack reported a reduction in despair and depression — factors that have been linked to an increased likelihood of death in heart attack patients.
  • Those who volunteered reported higher levels of happiness, life satisfaction, self-esteem, a sense of control over life and physical health, as well as lower levels of depression.

The more people volunteer the more likely they are to benefit from better health. But, interestingly, you have to be volunteering for the right reasons. Volunteering out of a feeling of compassion and expecting nothing in return is the only way to reap the positive health benefits of volunteering.

The fact that people who volunteer lead longer, healthier lives has some public health experts concluding that doctors should be recommending volunteering right alongside diet and exercise. An article in The Atlantic by James Hamblin cites a study by Eric Kim and Sara Konrath that proved volunteers were more likely to get flu shots, mammograms, Pap smears, cholesterol tests, and prostate exams. Most importantly, volunteering was associated with 38 percent fewer nights spent in the hospital.

“What this shows is that volunteers make decisions about their health that are different from non-volunteers,” Konrath told Hamblin. “One way to think about this is that when we care for ourselves, in a fundamental way, it allows us to care for others.” Based on their study, Kim and Konrath believe that physicians should recommend volunteering to all of their patients.

“The research on smoking is not experimental; it’s the exact same quality as the studies of volunteering,” Konrath added. “It’s based on following people over time and seeing what happens to people who choose to smoke or choose to volunteer. Yet doctors have no trouble telling us to stop smoking. What they ignore is that most of the context of our day-to-day lives is embedded within relationships. The number and quality of those relationships strongly influences health. I’ve been looking at this for years now, and I haven’t found a study where volunteering didn’t affect health positively in some way.”

When people are healthier and stay out of the hospital, it saves all of us money. Including companies. Beyond the research around the health outcomes of volunteers in the general population, a study by UnitedHealth Group found compelling evidence that employee volunteer programs improve the health of employees.

First: volunteering helps employees feel good. According to the study, over three quarters of employees who had volunteered during the last 12 months found that they felt healthier. Ninety-four percent reported that they had improved moods as a result of the work they were doing to create community impact. Volunteers were also significantly more likely to consider themselves in very good or excellent health. With sick days costing the American economy an estimated $576 billion every year, companies would much prefer to have a happy, healthy workforce, and employees also happen to like being healthy and happy. A win-win all around.

Here’s another aspect of employee volunteerism that should appeal to employers and employees alike: over three quarters of employees who volunteered in the last 12 months found that they had less stress. This leads to better health outcomes, with scientific studies conclusively demonstrating that higher stress levels and an inability to cope with stress lead to diminished overall health.

Not only were employees who volunteer more apt to feel calm and peaceful, they also reported that they felt more invigorated during the four weeks after they volunteer. Employees bring this increased energy to the workplace, making them more productive and impacting their company’s bottom line.

The UnitedHealth study found that an incredible 96 percent of employee volunteers believe that volunteering enriches their sense of purpose in life. Having a sense of purpose doesn’t just give your life more meaning or make you feel better — it’s also tied to one’s overall health. The Pacific Standard reported that a sense of purpose in one’s life can boost the immune system, which in turn leads to less time spent laying in bed fighting off a cold or flu. Another study found that overall brain health was boosted by a sense of purpose, including a lower rate of dementia and Alzheimer’s disease. The sense of purpose one gains from volunteering has tangible effects on an employee’s health and his company’s bottom line.

Your employees who volunteer aren’t just healthier, they’re also more engaged and active healthcare consumers. Four out of five believe that they have some degree of control over their health, know more about it and are more informed about chronic diseases. This means that they’ll make better decisions about their health and healthcare over the long term, which in turn leads to less sick days taken and a lower overall strain on healthcare budgets.

The UnitedHealth study adds to the body of evidence proving that volunteering is a health benefit that should be taken seriously. Employees who volunteer are not only more engaged, they’re mentally and physically healthier.

And that’s something that makes everyone feel better.