(dailyRx News) Stress is recognized as a risk factor for heart disease, and new research indicates social stress might trigger a biological process that leads to heart disease. But could a social activity such as group yoga and meditation effectively counter this potentially deadly forerunner?
How Stress Is Harmful
A study from Wake Forest University School of Medicine, published in the current issue of Obesity, found that social stress could be an important precursor to heart disease by causing the body to deposit more fat in the abdomen, thereby speeding the harmful buildup of plaque in blood vessels. As that plaque builds up, it blocks the flow of blood and could lead to a myriad of health problems all related to heart disease, the number one cause of death in the world.
Says Carol A. Shively, Ph.D., a professor of pathology and the study's principal investigator, "Much of the excess fat in many people who are overweight is located in the abdomen, and that fat behaves differently than fat in other locations. If there's too much, it can have far more harmful effects on health than fat located in other areas."
She notes that obesity is directly related to lower socioeconomic status in Western societies, as is heart disease. The people who have fewer resources to buffer themselves from the stresses of life are more likely to experience such health problems, she explains.
The study looked at how the stress of low social status affects the development of heart disease. The researchers fed female monkeys a Western-style diet containing fat and cholesterol. The monkeys were housed in groups so they would naturally establish a pecking order from dominant to subordinate. Subordinate monkeys are often the target of aggression and aren't included in group grooming sessions as often as dominant monkeys.
Shively and her colleagues, all faculty with the School of Medicine's section on comparative medicine, found that the socially stressed subordinate monkeys developed more fat in the viscera, or abdominal cavity. They also found that the stress of social subordination results in the release of stress hormones that promote fat deposits in the viscera. Visceral fat, in turn, promotes coronary artery atherosclerosis, the buildup of plaque in the blood vessels that leads to heart disease.
What is striking about that relationship, Shively points out, is that women and female monkeys have a natural protection against heart disease: Women typically develop heart disease an average of 10 years later than men do. However, that protection is lost, it appears, when stress levels rise and visceral fat increases. In support of that theory, the researchers found that the monkeys with high social stress and larger amounts of visceral fat also had ovaries that produced fewer protective hormones.
"Suppressed ovarian function is a very serious condition in a woman," Shively says. "Women who are hormone-deficient will develop more atherosclerosis and be at greater risk of developing coronary heart disease and other diseases such as osteoporosis and cognitive impairment."
Managing Stress at the Source
Identifying sources of stress is one of the first steps to dealing with it. And "dealing" with it often means removing or minimizing that source's influence on your life. For example, if your 30-minute drive into work every morning and every evening stresses you out, you could perhaps take the bus or train or carpool instead so you don't have to deal with the stress of driving in gridlock traffic.
Unfortunately, some sources of stress don't have easy solutions. As recent news stories have reported, the economic downturn has a lot of people stressed out, but there's only so much we all can do about our individual situations to lessen the stress we're feeling. Stress from the job, stress from the demands of parenthood, stress from one's economic situation are all very common, and they're all situations from which people can't readily escape in order to escape that stress.
Here's one possible solution: A recently published study found that 20 minutes daily of guided workplace meditation and yoga combined with six weekly group sessions can lower feelings of stress by more than 10 percent. Additionally, the stress-relieving program investigated improved sleep quality for the sedentary office employees who participated.
"Because chronic stress is associated with chronic disease, I am focusing on how to reduce stress before it has a chance to contribute to disease," says Maryanna Klatt, lead author of the study and an assistant professor of clinical allied medicine at Ohio State University.
Her study, published in a recent issue of Health Education & Behavior, offered participants a modified version of mindfulness-based stress reduction (MBSR), a program established in 1979 to help hospital patients in Massachusetts assist in their own healing. MBSR is now widely use around the world--and not just for convalescence.
In this context of MBSR, mindfulness refers in part to a person's heightened awareness of an external source of stress, which is the first step toward relaxing in a way that can minimize the effects of that stress on the body.
For the study, the researchers recruited 48 office workers with body mass index scores lower than 30 (30 is the threshold for obesity) who exercised less than 30 minutes most days of the week. Half of the participants were randomly chosen to take part in the stress-reduction intervention program, and the other half were put on a waiting list to take part later. Forty-two people completed the six-week study: 22 took part in the stress-reduction intervention and 20 people on the waiting list served as the control group.
The traditional MBSR program includes a daily hour-long practice for eight weeks supplemented along with a weekly session and a full-day retreat. However, the modified version used in this study was designed for office workers dressed in professional attire. Participants assigned to the intervention group attended one-hour weekly group meetings during lunch. At these sessions, they took part in breathing, relaxation and gentle yoga movement exercises, designed to coax participants toward a meditative state. They also discussed work-related stress. As part of the pursuit of mindfulness, they were coached to contemplate a specific topic in each session so they could explore their response to a specific type of stress over the past week.
"It doesn't matter what the stress is, but how you change the way you perceive the stress," notes Klatt. "I like to describe mindfulness as changing the way you see what's already there. It's a tool that teaches people to become aware of their options. If they can't change the external events in their life, they can instead change the way they view the stress, which can make a difference in how they experience their day-to-day life."
In addition to the weekly group sessions, the participants practiced 20 minutes of meditation and yoga daily at their desks. The solo sessions of movement and meditation were guided by verbal cues and music provided on CD that Klatt designed and recorded.
The researchers analyzed the participants' responses to the intervention using data from established research questionnaires that measure perceived stress, or the degree to which situations in life are considered stressful; a number of components of sleep quality, as well as mindful attention awareness, which refers to how often a person pays attention to and is aware of what is occurring in the present. All participants completed the questionnaires before and after the intervention. Researchers then compared the pre- and posttest results of the 22 adults who completed the intervention to those reported by the 20 control participants.
Mindful attention awareness increased significantly and perceived stress decreased significantly among the intervention group participants compared to the control group's responses. Overall sleep quality increased in both groups, but three of seven components of sleep were more affected in the intervention group.
On average, mindfulness increased by about 9.7 percent and perceived stress decreased by about 11 percent among the group that took part in the intervention. These participants also reported that they fell asleep in less time, had fewer sleep disturbances and experienced less daytime dysfunction than did members of the control group.
In addition to the questionnaire, the researchers collected data by taking saliva samples from participants to test for cortisol, a stress hormone. The researchers found no significant changes in average daily levels of the hormone over time for participants in both groups. Klatt notes that the design of this part of the pilot study could have affected the result and plans to change the sample collection technique in subsequent studies.
Klatt explains that mindfulness-based stress reduction, developed by Jon Kabat-Zinn at the University of Massachusetts Medical Center, has been studied widely and determined to be useful in lowering symptoms ranging from depression and anxiety to chronic pain. But the time commitment required by the traditional program makes it impractical for busy working professionals. In fact, adding a stress-reduction class outside of work could add stress to these people, she points out.
So Klatt set out to develop what she calls a "low dose" of the MBSR program that's suitable for the workplace and still offers stress-reduction benefits. She specifically scheduled weekly sessions during lunch to avoid conflicts with work or personal obligations, as well as combined movement with verbal prompts and music that are cues for participants to relax.
"As I've been working on the program, I heard so many of the participants say they wish they had learned this earlier," Klatt reveals. And once the results become more widely circulated, more people are sure to clamor for the intervention. However, because the low-dose program remains a work in progress, it's not yet available to the public.
With support from the National Institute of Health-funded General Clinical Research Center at Ohio State, Klatt and colleagues are building on these preliminary findings and continue to study the broader impact of the stress-reduction intervention in various groups, such as cancer survivors, intensive-care nurses and inner-city schoolchildren. In addition to gathering self-reported data from research participants, the researchers plan to collect biological samples to determine whether the program can lead to lower levels of stress hormones.
While researchers continue to examine the relationship between stress and health, these studies' results already reinforce basic health advice: Watch what you eat, exercise regularly and try to manage the stress in your life, which may mean incorporating some yoga or meditation into your daily routine.