People who have upbeat outlooks on life have significantly better cardiovascular health, a new study reveals. The findings, published in the January/February 2015 issue of Health Behavior and Policy Review, add to a rapidly expanding line of research identifying psychological factors as key determinants of physical health and disease.
“Individuals with the highest levels of optimism have twice the odds of being in ideal cardiovascular health compared to their more pessimistic counterparts,” said lead author Dr. Rosalba Hernandez, a professor of social work at the University of Illinois (UI). “This association remains significant, even after adjusting for socio-demographic characteristics and poor mental health.”
The link between psychological and physical well-being is well documented, particularly in the area of cardiovascular health. Many previous studies have shown that negative mental states — including stress, depression, and hostility/anger — can be harmful to heart health. More recently, however, researchers have begun to uncover how positive psychological characteristics can impact heart health.
Studies have found, for instance, that optimism — broadly defined as positive expectancies about the future — may offer protective benefits against adverse cardiovascular outcomes including stroke and increases in carotid artery blockage. There is also evidence demonstrating that optimistic people have healthier lipid profiles, better immune functioning, lower cortisol levels (indicative of lower physiological stress levels), and reduced stress-related inflammation.
Seven indicators of heart health
In this latest study, the UI team looked at the associations between optimism and heart health in more than 5,100 adults. The researchers used seven metrics to assess participants’ cardiovascular health: blood pressure, body mass index, fasting plasma glucose and serum cholesterol levels, dietary intake, physical activity and tobacco use — the same metrics used by the American Heart Association (AHA) to define heart health and targeted by the AHA in its “Life’s Simple 7” (LS7) public awareness campaign.
In accordance with AHA’s heart-health criteria, the researchers allocated 0, 1 or 2 points — representing poor, intermediate and ideal scores, respectively — to participants on each of the seven health metrics, which were then summed to arrive at a total cardiovascular health score. Participants’ total health scores ranged from 0 to 14, with a higher total score indicative of better health.
The participants, who ranged in age from 45-84, also completed surveys that assessed their mental health, levels of optimism, and physical health, based upon self-reported extant medical diagnoses of arthritis, liver and kidney disease.
Optimistic people twice as likely to have ideal heart health
The researchers found that individuals’ total health scores increased in tandem with their levels of optimism. People who were the most optimistic were 50 and 76 percent more likely to have total health scores in the intermediate or ideal ranges, respectively.
The association between optimism and cardiovascular health was even stronger when socio-demographic characteristics such as age, race and ethnicity, income and education status were factored in. People who were the most optimistic were twice as likely to have ideal cardiovascular health, and 55 percent more likely to have a total health score in the intermediate range, the researchers found. This could have important clinical implications, said Dr. Hernandez, particularly in light of a 2013 study found that a one-point increase in an individual’s total-health score on the LS7 was associated with an 8 percent reduction in their risk of stroke.
Further analysis revealed that optimists had significantly better blood sugar and total cholesterol levels than their counterparts. They were also more physically active, had healthier body mass indexes and were less likely to smoke, the researchers found.
Dr. Fernandez says the mounting evidence of the protective benefits of optimism signals an important area to explore further, particularly given the burden of cardiovascular problems in the nation. The Centers for Disease Control and Prevention estimates that heart disease causes one in four deaths in the United States, while someone has a stroke every 40 seconds.
“At the population level, even this moderate difference in cardiovascular health translates into a significant reduction in death rates,” she said. “This evidence, which is hypothesized to occur through a biobehavioral mechanism, suggests that prevention strategies that target modification of psychological well-being — e.g., optimism — may be a potential avenue for AHA to reach its goal of improving Americans’ cardiovascular health by 20 percent before 2020.”
Longitudinal analysis underway
Believed to be the first study to examine the association of optimism and cardiovascular health in a large, ethnically and racially diverse population, the sample for the current study was 38 percent white, 28 percent African-American, 22 percent Hispanic/Latino and 12 percent Chinese.
Data for the study were derived from the Multi-Ethnic Study of Atherosclerosis, an ongoing examination of subclinical cardiovascular disease that includes 6,000 people from six U.S. regions, including Baltimore, Chicago, Forsyth County in North Carolina, and Los Angeles County.
Begun in July 2000, MESA followed participants for 11 years, collecting data every 18 months to two years. Dr. Hernandez, who is an affiliated investigator on MESA, is leading a team in conducting prospective analyses on the associations found between optimism and heart health. In 2012, the Harvard team published the first and largest systematic review on the topic, finding a connection between optimism and a reduced risk of heart attacks, strokes, and other cardiovascular events.
“We now have available data to examine optimism at baseline and cardiovascular health a decade later,” said Dr. Hernandez. She expects the team will have an abstract on the longitudinal analysis completed in 2015.
Among other things, Dr. Hernandez said they hope their future research will help them sort out exactly how optimism and heart health are related. For instance, although the evidence clearly suggests a connection, it is not yet known whether optimism or healthy behaviors come first. It could be that happier, more positive people are more likely to engage in healthy behaviors, which in turn improves factors like blood pressure. It could also be that engaging in healthy behaviors and having a better biological profile helps boost psychological well-being. Longitudinal data will help resolve these questions, said Dr. Hernandez.