The unexpected finding has been made by University of Michigan and it will be published in the Psychological Science, a journal of the Association for Psychological Science.
The study supports earlier research showing that in terms of health and longevity, it really is better to give than to receive.
"These findings suggest that caregivers may actually benefit from providing care under some circumstances," said U-M researcher Stephanie Brown, lead author of the study report.
"Previous studies have documented negative health effects of caregiving. But the current results show that it is time to disentangle the presumed stress of providing help from the stress of witnessing a loved one suffer," the researcher added.
For the study, Brown and colleagues reviewed seven years of data from the U-M Health and Retirement Study, a nationally representative sample of Americans age 70 and older. The analysis focused on 1,688 couples, all of whom lived on their own.
At the start of the study in 1993, both members of each couple reported how much help they received from their spouse with a long list of everyday activities. These included eating, dressing and bathing, preparing meals, managing money and taking medications.
The vast majority - approximately 81 percent -said they received no help at all from their spouse. Another nine percent reported getting less than 14 hours of help a week, and the remaining ten percent reported getting 14 hours of help or more each week.
Over the course of the study, 909 people died - about 27 percent of the study population. After controlling for health, age, race, gender, education, employment status and net worth, Brown and colleagues found that the individuals who provided at least 14 hours of care a week to their spouses were significantly less likely to have died during the study period than those who provided no spousal care.
The results of this study add to a growing literature on the positive, beneficial health effects of caregiving, helping and altruism, according to Brown.