Stress-induced immune dysfunction: implications for health.

Folk wisdom has long suggested that stressful events take a toll on health. The field of psychoneuroimmunology (PNI) is now providing key mechanistic evidence about the ways in which stressors--and the negative emotions that they generate--can be translated into physiological changes. PNI researchers have used animal and human models to learn how the immune system communicates bidirectionally with the central nervous and endocrine systems and how these interactions impact on health.

Yoga and self-reported cognitive problems in breast cancer survivors: a randomized controlled trial.

OBJECTIVES: Cancer survivors often report cognitive problems. Furthermore, decreases in physical activity typically occur over the course of cancer treatment. Although physical activity benefits cognitive function in noncancer populations, evidence linking physical activity to cognitive function in cancer survivors is limited. In our recent randomized controlled trial, breast cancer survivors who received a yoga intervention had lower fatigue and inflammation following the trial compared with a wait list control group. This secondary analysis of the parent trial addressed yoga's impact on cognitive complaints. METHODS: Posttreatment stage 0-IIIA breast cancer survivors (n = 200) were randomized to a 12-week, twice-weekly Hatha yoga intervention or a wait list control group. Participants reported cognitive complaints using the Breast Cancer Prevention Trial Cognitive Problems Scale at baseline, immediately postintervention, and 3-month follow-up. RESULTS: Cognitive complaints did not differ significantly between groups immediately postintervention (p = 0.250). However, at 3-month follow-up, yoga participants' Breast Cancer Prevention Trial Cognitive Problems Scale scores were an average of 23% lower than wait list participants' scores (p = 0.003). These group differences in cognitive complaints remained after controlling for psychological distress, fatigue, and sleep quality. Consistent with the primary results, those who practiced yoga more frequently reported significantly fewer cognitive problems at 3-month follow-up than those who practiced less frequently (p < 0.001). CONCLUSIONS: These findings suggest that yoga can effectively reduce breast cancer survivors' cognitive complaints and prompt further research on mind-body and physical activity interventions for improving cancer-related cognitive problems.

Attachment anxiety is related to Epstein-Barr virus latency.

Attachment theory provides a framework for understanding individual differences in chronic interpersonal stress. Attachment anxiety, a type of relationship insecurity characterized by worry about rejection and abandonment, is a chronic interpersonal stressor. Stress impacts cellular immunity, including herpesvirus reactivation. We investigated whether attachment anxiety was related to the expression of a latent herpesvirus, Epstein-Barr virus (EBV), when individuals were being tested for breast or colon cancer and approximately 1 year later. Participants (N=183) completed a standard attachment questionnaire and provided blood to assess EBV viral capsid antigen (VCA) IgG antibody titers. Individuals with more attachment anxiety had higher EBV VCA IgG antibody titers than those with less attachment anxiety. The strength of the association between attachment anxiety and antibody titers was the same at both assessments. This study is the first to show an association between latent herpesvirus reactivation and attachment anxiety. Because elevated herpesvirus antibody titers reflect poorer cellular immune system control over the latent virus, these data suggest that high attachment anxiety is associated with cellular immune dysregulation.

Stress and anxiety effects on positive skin test responses in young adults with allergic rhinitis.

BACKGROUND: Anxiety and psychological stress affect allergy-related immune function. How these relations influence the evaluations of patients with allergic rhinitis is unknown. OBJECTIVE: To examine whether anxiety and stress exposure affect skin prick test (SPT) responses to common allergens for which patients with atopy showed no prior positive SPT response. METHODS: Patients with allergic rhinitis, evidenced by clinical history and SPT results, were admitted twice to a hospital research unit for 4 hours. In a crossover design, SPT wheals were assessed before and after the Trier Social Stress Test and then the following morning; for comparison, SPT wheals were assessed before and after a laboratory session without a stressor. Analyses focused on wheal responses for common allergens that tested negative (wheal size <3 mm larger than saline) from SPTs performed at multiple baseline assessments. RESULTS: After the Trier Social Stress Test, more anxious patients with atopy had a higher incidence of positive SPT reactions to antigens that previously tested negative. Anxiety was unrelated to positive SPT incidence under nonstressful conditions. Based on clinical symptom reports, newly positive SPT reactions after the stressor were apparently corrections of previously false-negative SPT reactions. The SPT wheal responses for allergens previously testing negative were enhanced after a stressor. Histamine (positive control) or saline (negative control) SPT responses were not affected. CONCLUSION: A laboratory stressor affected allergen SPT responses in more anxious patients with allergic rhinitis. In addition to clinical history, assessment of anxiety and current stress at the time of the SPT may provide valuable information about a patient's allergic status and aid in clinical decision making.

Stress-induced inflammatory responses in women: effects of race and pregnancy.

OBJECTIVE: African Americans experience preterm birth at nearly twice the rate of whites. Chronic stress associated with minority status is implicated in this disparity. Inflammation is a key biological pathway by which stress may affect birth outcomes. This study examined the effects of race and pregnancy on stress-induced inflammatory responses. METHODS: Thirty-nine women in the second trimester of pregnancy (19 African American, 20 white) and 39 demographically similar nonpregnant women completed an acute stressor (Trier Social Stress Test). Psychosocial characteristics, health behaviors, and affective responses were assessed. Serum interleukin (IL)-6 was measured at baseline, 45 minutes, and 120 minutes poststressor. RESULTS: IL-6 responses at 120 minutes poststressor were 46% higher in African Americans versus whites (95% confidence interval = 8%-81%, t(72) = 3.51, p = .001). This effect was present in pregnancy and nonpregnancy. IL-6 responses at 120 minutes poststressor tended to be lower (15%) in pregnant versus nonpregnant women (95% confidence interval = -5%-32%, p = .14). Racial differences in inflammatory responses were not accounted for by demographics, psychological characteristics, health behaviors, or differences in salivary cortisol. Pregnant whites showed lower negative affective responses than did nonpregnant women of either race (p values ≤ .007). CONCLUSIONS: This study provides novel evidence that stress-induced inflammatory responses are more robust among African American women versus whites during pregnancy and nonpregnancy. The ultimate impact of stress on health is a function of stressor exposure and physiological responses. Individual differences in stress-induced inflammatory responses represent a clear target for continued research efforts in racial disparities in health during pregnancy and nonpregnancy.

Attachment anxiety is linked to alterations in cortisol production and cellular immunity.

Although evidence suggests that attachment anxiety may increase risk for health problems, the mechanisms underlying these effects are not well understood. In the current study, married couples (N = 85) provided saliva samples over 3 days and blood samples on two occasions. Participants with higher attachment anxiety produced more cortisol and had fewer numbers of CD3(+) T cells, CD45(+) T cells, CD3(+)CD4(+) helper T cells, and CD3(+)CD8(+) cytotoxic T cells than participants with lower attachment anxiety. Higher cortisol levels were also related to fewer numbers of CD3(+), CD45(+), CD3(+)CD4(+), and CD3(+)CD8(+) cells, which is consistent with research showing that cortisol alters the cellular immune response. These data suggest that attachment anxiety may have physiological costs, and they provide a glimpse into the pathways through which social relationships affect health. The current study also extends attachment theory in an important new direction by demonstrating the utility of a psychoneuroimmunological approach to the study of attachment anxiety, stress, and health.

Loneliness promotes inflammation during acute stress.

Although evidence suggests that loneliness may increase risk for health problems, the mechanisms responsible are not well understood. Immune dysregulation is one potential pathway: Elevated proinflammatory cytokines such as interleukin-6 (IL-6) increase risk for health problems. In our first study (N = 134), lonelier healthy adults exposed to acute stress exhibited greater synthesis of tumor necrosis factor-alpha (TNF-α) and IL-6 by peripheral blood mononuclear cells (PBMCs) stimulated with lipopolysaccharide (LPS) than their less lonely counterparts. Similarly, in the second study (N = 144), lonelier posttreatment breast-cancer survivors exposed to acute stress exhibited greater synthesis of IL-6 and interleukin-1 beta (IL-1ß) by LPS-stimulated PBMCs than their counterparts who felt more socially connected. However, loneliness was unrelated to TNF-α in Study 2, although the result was in the expected direction. Thus, two different populations demonstrated that lonelier participants had more stimulated cytokine production in response to stress than less lonely participants, which reflects a proinflammatory phenotype. These data provide a glimpse into the pathways through which loneliness may affect health.

Use of ß-blockers and mortality following ovarian cancer diagnosis: a population-based cohort study.

BACKGROUND: Experimental data suggest that catecholamine hormones are involved in stimulating the aggressiveness of ovarian cancer, but few population-based studies have examined this association. We therefore conducted a population-based cohort study to examine whether ß-blockers affect mortality following ovarian cancer diagnosis. METHODS: We used the Danish Cancer Registry to identify all patients diagnosed with ovarian cancer in northern Denmark between 1999 and 2010 (n=6,626). Data on medication use, comorbidity, and survival were obtained from medical databases. According to the last redeemed prescription before diagnosis, ß-blocker use was categorized as current (within ≤90 days), previous (>90 days) or never. We used Cox proportional hazards regression to calculate hazard ratios (HRs) for all-cause mortality with 95% confidence intervals (CIs) adjusting for confounding factors. RESULTS: Among the ovarian cancer patients, 373 (5.6%) were current, 87 (1.3%) previous, and 6,166 (93.1%) were nonusers of ß-blockers. Median duration of use was 19.0 months among current users and 43.0 months among previous users. Median follow-up was 2.55 years (IQR: 0.81-9.23). Nonusers and current users of ß-blockers had similar comorbidity burden whereas previous users had moderate comorbidity more frequently. Compared with nonusers, the adjusted HR was 1.17 (95% CI: 1.02-1.34) for current users and 1.18 (95% CI: 0.90-1.55) for previous users. Secondary analyses stratifying by cancer stage and duration of ß-blocker use supported the overall results. CONCLUSIONS: We found no evidence that ß-blocker use was associated with decreased mortality following ovarian cancer diagnosis.

Stressful early life experiences and immune dysregulation across the lifespan.

There is considerable evidence that stressful early life events influence a variety of physical health problems later in life. Childhood adversity has been linked to elevated rates of morbidity and mortality from a number of chronic diseases. Immune dysregulation may be one potential pathway that explains this link. In this mini-review, we summarize human studies demonstrating that severe early life stressors have lasting immune consequences. We propose a model outlining potential biobehavioral pathways that explain how early life stressors leave people vulnerable to these maladaptive outcomes. Finally, we suggest ideas for future work to test different aspects of this model.

Depressive symptoms enhance stress-induced inflammatory responses.

Depression is a risk factor for morbidity and mortality, and immune dysregulation may be partially responsible for this link. Proinflammatory cytokines such as interleukin 6 (IL-6) are reliable predictors of quality of life, morbidity, and many causes of mortality. The current study evaluated relationships between depressive symptoms, as assessed by the CES-D, and stress-induced inflammation. The participants, 138 healthy adults, were evaluated at rest, and after a standardized laboratory speech and mental arithmetic stressor. Compared with individuals with fewer depressive symptoms, those with more depressive symptoms produced more IL-6 in response to the stressor, as well as significantly higher levels of IL-6 both 45 min and 2 h after the stressor. These findings add to our emerging understanding of the complex interactions among stress, depression, and immune dysregulation, and provide one potential pathway to explain relationships between depressive symptoms and disease.

Omega-3 fatty acids, oxidative stress, and leukocyte telomere length: A randomized controlled trial.

Shorter telomeres have been associated with poor health behaviors, age-related diseases, and early mortality. Telomere length is regulated by the enzyme telomerase, and is linked to exposure to proinflammatory cytokines and oxidative stress. In our recent randomized controlled trial, omega-3 (n-3) polyunsaturated fatty acid (PUFA) supplementation lowered the concentration of serum proinflammatory cytokines. This study assessed whether n-3 PUFA supplementation also affected leukocyte telomere length, telomerase, and oxidative stress. In addition to testing for group differences, changes in the continuous n-6:n-3 PUFA ratio were assessed to account for individual differences in adherence, absorption, and metabolism. The double-blind four-month trial included 106 healthy sedentary overweight middle-aged and older adults who received (1) 2.5g/day n-3 PUFAs, (2) l.25g/day n-3 PUFAs, or (3) placebo capsules that mirrored the proportions of fatty acids in the typical American diet. Supplementation significantly lowered oxidative stress as measured by F2-isoprostanes (p=0.02). The estimated geometric mean log-F2-isoprostanes values were 15% lower in the two supplemented groups compared to placebo. Although group differences for telomerase and telomere length were nonsignificant, changes in the n-6:n-3 PUFA plasma ratios helped clarify the intervention's impact: telomere length increased with decreasing n-6:n-3 ratios, p=0.02. The data suggest that lower n-6:n-3 PUFA ratios can impact cell aging. The triad of inflammation, oxidative stress, and immune cell aging represents important pre-disease mechanisms that may be ameliorated through nutritional interventions. This translational research broadens our understanding of the potential impact of the n-6:n-3 PUFA balance. ClinicalTrials.gov identifier: NCT00385723.

Epstein-Barr virus reactivation during pregnancy and postpartum: effects of race and racial discrimination.

OBJECTIVE: Adverse pregnancy outcomes, including preterm birth, are markedly higher among African-Americans versus Whites. Stress-induced immune dysregulation may contribute to these effects. Epstein-Barr virus (EBV) reactivation provides a robust model for examining cellular immune competence. This study examined associations of EBV virus capsid antigen immunoglobulin G (VCA IgG) with gestational stage, race, and racial discrimination in women during pregnancy and postpartum. METHODS: Fifty-six women (38 African-American, 18 White) were included. African-Americans and Whites did not differ in age, education, income, parity, or body mass index (ps ≥ .51). During the 1st, 2nd, and 3rd trimester and ~5 weeks postpartum, women completed measures of racial discrimination, perceived stress, anxiety, depressive symptoms and health behaviors. EBV VCA IgG antibody titers were measured via ELISA in serum collected at each visit. RESULTS: In the overall sample, EBV VCA IgG antibody titers were lower in the 3rd versus 1st trimester (p=.002). At every timepoint (1st, 2nd, 3rd trimester and postpartum), African-American women exhibited higher serum EBV VCA IgG antibody titers than Whites (ps<.001). This effect was most pronounced among African-Americans reporting greater racial discrimination [p=.03 (1st), .04 (2nd), .12 (3rd), .06 (postpartum)]. Associations of race and racial discrimination with EBV VCA IgG antibody titers were not accounted for by other measures of stress or health behaviors. CONCLUSIONS: Compared to Whites, African-American women showed higher EBV VCA IgG antibody titers, indicative of impaired cellular immune competence, across pregnancy and postpartum. This effect was particularly pronounced among African-American women reporting greater racial discrimination, supporting a role for chronic stress in this association. In women overall, EBV antibody titers declined during late as compared to early pregnancy. This may be due to pregnancy-related changes in cell-mediated immune function, humoral immune function, and/or antibody transfer to the fetus in late gestation. As a possible marker of stress-induced immune dysregulation during pregnancy, the role of EBV reactivation in racial disparities in perinatal health warrants further attention.

Omega-3 supplementation lowers inflammation in healthy middle-aged and older adults: a randomized controlled trial.

Observational studies have linked lower levels of omega-3 (n-3) polyunsaturated fatty acids (PUFAs) with inflammation and depression. This study was designed to determine whether n-3 supplementation would decrease serum cytokine production and depressive symptoms in 138 healthy middle-aged and older adults (average age=51.04, SD=7.76) who were sedentary and overweight (average BMI=30.59, SD=4.50). This three-arm randomized, placebo-controlled, double-blind 4-month trial compared responses to (1) 2.5 g/d n-3 PUFAs, or (2) 1.25 g/d n-3 PUFAs, or (3) placebo capsules that mirrored the proportions of fatty acids in the typical American diet. Serum interleukin-6 decreased by 10% and 12% in our low and high dose n-3 groups, respectively, compared to a 36% increase in the placebo group. Similarly, low and high dose n-3 groups showed modest 0.2% and -2.3% changes in serum tumor necrosis factor alpha, compared to a 12% increase in the control group. Depressive symptoms were quite low at baseline and did not change significantly in response to supplementation. Our data suggest that n-3 PUFAs can reduce inflammation in overweight, sedentary middle-aged and older adults, and thus could have broad health benefits. These data provide a window into the ways in which the n-3 PUFAs may impact disease initiation, progression, and resolution. ClinicalTrials.gov identifier: NCT00385723.

Inflammation and reactivation of latent herpesviruses in older adults.

Inflammation increases with age and is associated with many chronic diseases that are prevalent among older adults. Persistent pathogens such as latent herpesviruses and chronic bacterial infections can act as a source of inflammation. Herpesviruses, including Epstein-Barr virus (EBV) and cytomegalovirus (CMV), establish latent infections following primary infection and reactivate when the cellular immune system is compromised. EBV and CMV replication can induce proinflammatory cytokine production and thus could influence systemic inflammation. The present study addressed relationships among EBV and CMV antibody titers, and levels of C-reactive protein (CRP) and interleukin-6 (IL-6) in a sample of 222 community dwelling older adults (mean(age)=64.1±14.1 years). Participants were divided into two groups based on whether they were EBV seropositive and CMV seronegative (EBV+CMV-), or EBV and CMV seropositive (EBV+CMV+). Among individuals who were EBV+CMV-, EBV antibody titers were not associated with either CRP or IL-6 levels. However, among those who were EBV+CMV+, higher EBV antibody titers were related to elevated levels of CRP and IL-6 in those individuals with higher CMV antibody titers; there was no relationship between EBV antibody titers and CRP or IL-6 levels in those participants with lower CMV antibody titers. These data suggest that the combination of latent EBV and CMV reactivation (indexed by antibody titers) may boost CRP and IL-6 production. Thus, reactivation of multiple herpesviruses may drive inflammation and could contribute to poorer health among older adults.

Fatigue and herpesvirus latency in women newly diagnosed with breast cancer.

Fatigue is a notable clinical problem in cancer survivors, and understanding its pathophysiology is important. The current study sought to determine biomarkers of fatigue that exist before cancer treatment. Relationships between the expression of latent Epstein-Barr virus (EBV) and cytomegalovirus (CMV) and fatigue were examined in 158 women newly diagnosed with breast cancer or awaiting a positive diagnostic result. Higher CMV antibody titers, but not EBV antibody titers, were associated with a greater likelihood of being fatigued. Associations between fatigue and higher CMV antibody titers remained after controlling for alcohol use, smoking, comorbidities, depressive symptoms, age, BMI, cancer stage, and sleep problems. More sleep problems and higher levels of depressive symptoms were also associated with a greater likelihood of being fatigued. CMV antibody titers, but not EBV antibody titers, were associated with higher levels of C-reactive protein (CRP), but CRP was not associated with fatigue. When the cellular immune system is compromised, reactivation of latent herpesviruses may fuel chronic inflammatory responses. Prior work has suggested that fatigue may be related to inflammation and its associated sickness behaviors; accordingly, our findings may be tapping into this same physiological substrate.

Childhood abuse and inflammatory responses to daily stressors.

BACKGROUND: Childhood abuse leads to greater morbidity and mortality in adulthood. Dysregulated physiological stress responses may underlie the greater health risk among abused individuals. PURPOSE: This study evaluated the impact of childhood abuse on inflammatory responses to naturalistically occurring daily stressors. METHODS: In this cross-sectional study of 130 older adults, recent daily stressors and childhood abuse history were evaluated using the Daily Inventory of Stressful Events and the Childhood Trauma Questionnaire. Blood samples provided data on circulating interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP). RESULTS: Childhood abuse history moderated IL-6 levels but not TNF-α and CRP responses to daily stressors. Individuals with a childhood abuse history who experienced multiple stressors in the past 24 h had IL-6 levels 2.35 times greater than those of participants who reported multiple daily stressors but no early abuse history. CONCLUSION: Childhood abuse substantially enhances IL-6 responses to daily stressors in adulthood.

Childhood adversity heightens the impact of later-life caregiving stress on telomere length and inflammation.

OBJECTIVE: To address the question of whether childhood abuse and other adversities have lasting, detectable consequences for inflammation and cell aging late in life, and whether the effects are large enough to be discernible beyond that of a major chronic stressor, dementia family caregiving. Previous research on the physical health consequences of childhood abuse and other adversities has been based on data from young or middle-aged adults. METHOD: In this community sample of 132 healthy older adults (mean age = 69.70 years; standard deviation = 10.14), including 58 dementia family caregivers and 74 non-caregivers, blood samples were analyzed for interleukin (IL)-6, tumor necrosis factor (TNF)-α, and telomere length, a measure of cell aging. Depressive symptoms were assessed by the Center for Epidemiological Studies Depression Scale. RESULTS: After controlling for age, caregiving status, gender, body mass index, exercise, and sleep, the presence of multiple childhood adversities was related to both heightened IL-6 (0.37 ± 0.03 log10 pg/mL versus 0.44 ± 0.03 log10 pg/mL) and shorter telomeres (6.51 ± 0.17 Kb versus 5.87 ± 0.20 Kb), compared with the absence of adversity; the telomere difference could translate into a 7- to 15-year difference in life span. Abuse was associated with heightened IL-6 and TNF-α levels; for TNF-α, this relationship was magnified in caregivers compared with controls. Moreover, abuse and caregiving status were associated significantly and independently with higher levels of depressive symptoms. CONCLUSIONS: Adverse childhood events are related to continued vulnerability among older adults, enhancing the impact of chronic stressors. Childhood adversities cast a very long shadow.

Omega-3 supplementation lowers inflammation and anxiety in medical students: a randomized controlled trial.

Observational studies have linked lower omega-3 (n-3) polyunsaturated fatty acids (PUFAs) and higher omega-6 (n-6) PUFAs with inflammation and depression, but randomized controlled trial (RCT) data have been mixed. To determine whether n-3 decreases proinflammatory cytokine production and depressive and anxiety symptoms in healthy young adults, this parallel group, placebo-controlled, double-blind 12-week RCT compared n-3 supplementation with placebo. The participants, 68 medical students, provided serial blood samples during lower-stress periods as well as on days before an exam. The students received either n-3 (2.5 g/d, 2085 mg eicosapentaenoic acid and 348 mg docosahexanoic acid) or placebo capsules that mirrored the proportions of fatty acids in the typical American diet. Compared to controls, those students who received n-3 showed a 14% decrease in lipopolysaccharide (LPS) stimulated interleukin 6 (IL-6) production and a 20% reduction in anxiety symptoms, without significant change in depressive symptoms. Individuals differ in absorption and metabolism of n-3 PUFA supplements, as well as in adherence; accordingly, planned secondary analyses that used the plasma n-6:n-3 ratio in place of treatment group showed that decreasing n-6:n-3 ratios led to lower anxiety and reductions in stimulated IL-6 and tumor necrosis factor alpha (TNF-α) production, as well as marginal differences in serum TNF-α. These data suggest that n-3 supplementation can reduce inflammation and anxiety even among healthy young adults. The reduction in anxiety symptoms associated with n-3 supplementation provides the first evidence that n-3 may have potential anxiolytic benefits for individuals without an anxiety disorder diagnosis. ClinicalTrials.gov identifier: NCT00519779.

The EBV-encoded dUTPase activates NF-kappa B through the TLR2 and MyD88-dependent signaling pathway.

The innate immune response plays a key role as the primary host defense against invading pathogens including viruses. We have previously shown that treatment of human monocyte-derived macrophages with EBV-encoded dUTPase induces the expression of proinflammatory cytokines through the activation of NF-kappaB. However, the receptor responsible for EBV-encoded dUTPase-mediated biological effects is not known. In this study, we demonstrate that the purified EBV-encoded dUTPase activates NF-kappaB in a dose-dependent manner through TLR2 and requires the recruitment of the adaptor molecule MyD88 but not CD14. Furthermore, activation of NF-kappaB was abrogated by anti-TLR2, anti-EBV-encoded dUTPase blocking Abs and the overexpression of a dominant negative construct of MyD88 in human embryonic kidney 293 cells expressing TLR2. In addition, treatment of human monocyte-derived macrophages with the anti-EBV-encoded dUTPase Ab 7D6 or the anti-TLR2 Ab blocked the production of IL-6 by the EBV-encoded dUTPase. To our knowledge, this is the first report demonstrating that a nonstructural protein encoded by EBV is a pathogen-associated molecular pattern and that it has immunomodulatory functions. Although additional studies are necessary to define the signaling pathways activated by the EBV-encoded dUTPase and to determine its role in modulating immune responses to EBV infection, our results suggest that the dUTPase could be a potential target for the development of novel therapeutic agents against infections caused by EBV.

Stress, inflammation, and yoga practice.

OBJECTIVE: To address the mechanisms underlying hatha yoga's potential stress-reduction benefits, we compared inflammatory and endocrine responses of novice and expert yoga practitioners before, during, and after a restorative hatha yoga session, as well as in two control conditions. Stressors before each of the three conditions provided data on the extent to which yoga speeded an individual's physiological recovery. METHODS: A total of 50 healthy women (mean age, 41.32 years; range, 30-65 years), 25 novices and 25 experts, were exposed to each of the conditions (yoga, movement control, and passive-video control) during three separate visits. RESULTS: The yoga session boosted participants' positive affect compared with the control conditions, but no overall differences in inflammatory or endocrine responses were unique to the yoga session. Importantly, even though novices and experts did not differ on key dimensions, including age, abdominal adiposity, and cardiorespiratory fitness, novices' serum interleukin (IL)-6 levels were 41% higher than those of experts across sessions, and the odds of a novice having detectable C-reactive protein (CRP) were 4.75 times as high as that of an expert. Differences in stress responses between experts and novices provided one plausible mechanism for their divergent serum IL-6 data; experts produced less lipopolysaccharide-stimulated IL-6 in response to the stressor than novices, and IL-6 promotes CRP production. CONCLUSION: The ability to minimize inflammatory responses to stressful encounters influences the burden that stressors place on an individual. If yoga dampens or limits stress-related changes, then regular practice could have substantial health benefits.