A study found yoga to be an effective means to reduce oxidative stress and to improve antioxidant defense in elderly hypertensive individuals.45
In another, small study, researchers found that regular yoga practice could decrease oxidative stress and improve antioxidant levels, in addition to significantly increasing certain aspects of immune function and stress.
Young, healthy university students volunteered for the study and were assigned either to a control group (13) who did no yoga, or a yoga group (12) who practiced yoga with an instructor for 90 minutes once a week for 12 weeks, with daily home-based practice for the duration.65
At the end of the 12-week study, the yoga group had significant decreases in markers for oxidative stress such as blood levels of nitric oxide, F2-isoprostane, and lipid peroxide. Antioxidant levels and activity, including total glutathione (GSH), activities of GSH-peroxidase, and GSH-s-transferase were remarkably increased after yoga practice compared with the control group.
The researchers also noted that the yoga group had a significant increase in immune-related cytokines, such as interleukin-12 and interferon-gamma, suggesting immune benefits of yoga. The students practicing yoga also had significant reductions in levels of adrenalin and increased levels of serotonin compared with the control group, suggesting enhanced stress management.
A study exploring the efficacy of yoga to increase affect tolerance and to decrease PTSD symptomatology found yoga significantly reduced symptoms of PTSD and improved the functioning of traumatized individuals.12
In a small pilot study, researchers assessed the potential benefits of a yoga program as an adjunctive therapy for improving PTSD symptoms in veterans with military-related PTSD. Twelve veterans took part in a 6 week yoga intervention held twice a week, and the researchers observed a significant improvement in PTSD hyperarousal symptoms and overall sleep quality as well as daytime dysfunction related to sleep.
The intervention was not associated with significant improvements in total PTSD, anger, or quality of life, but the researcher concluded that yoga may be an effective adjunctive therapy for some symptoms of PTSD in veterans.66
The breathing and meditation techniques can help enhance health and relaxation for those who are pregnant, and support mental focus to aid childbirth. Some postures are chosen specifically to help encourage an optimal fetal position.50
In a survey ascertaining the opinions, practices and knowledge about exercise, including yoga, during pregnancy:51
woman taking part in pregnancy yoga
Yoga may help improve stress levels, quality of life, and labor parameters such as comfort, pain, and duration in pregnant women.
86% of women responded that exercise during pregnancy is beneficial
83% felt it was beneficial to start prior to pregnancy
62% considered walking to be the most beneficial form of exercise
64% of respondents were currently exercising during pregnancy
51% exercised 2-3 times a week
65% considered yoga to be beneficial
40% had attempted yoga before pregnancy.
Another study tested the efficacy of yoga as an intervention for reducing maternal anxiety during pregnancy.
A single session of yoga reduced both subjective and physiological measures of state anxiety and the reduction in anxiety persisted at the final session of the intervention. Antenatal yoga seems to be useful for reducing women's anxieties toward childbirth and preventing increases in depressive symptomatology.52
Yoga group participants show fewer postpartum but not antepartum depressive symptoms than control group participants. Findings indicate that prenatal hatha yoga may improve current mood and may be effective in reducing postpartum depressive symptoms.53
A systematic review of yoga in pregnancy showed that studies indicate that yoga may produce improvements in stress levels, quality of life, aspects of interpersonal relations, autonomic nervous system functioning, and labor parameters such as comfort, pain, and duration. However, they conclude that more randomized controlled trials are needed to provide more information regarding the utility of yoga interventions for pregnancy.54
In one study, women aged 32-66 years with restless legs syndrome completed 16 yoga classes over an 8-week period. At the end of the study, participants demonstrated striking reductions in symptoms of restless legs syndrome and decreased symptom severity. Symptoms were reduced to minimal/mild in all but one woman and no participant reported severe symptoms by week 8. Participants also showed significant improvements in sleep, perceived stress, and mood.58
Compared with controls, the yoga group reported significant subjective improvements in a range of measures, including:57
Overall sleep quality
Sleep efficiency
Sleep latency and duration
Self-assessed sleep quality
Fatigue
General well-being
Depression
Anxiety
Stress
Tension
Anger
Vitality
Function in physical, emotional, and social roles.
Another study found that an 8-week yoga intervention in 20 people with chronic insomnia led to statistically significant improvements in sleep efficiency, total sleep time, total wake time, sleep onset latency (how long it takes to fall asleep), and wake time after sleep onset.67
children practicing yoga
Studies suggest that school-based yoga may assist with stress management and the behavior of children.
One study found that yoga may help children and young people cope with stress and, as a result, could contribute positively to balance in life, well-being, and mental health.10
Another study evaluated the influence of hatha yoga practice on levels of distress in women about to begin a course of in vitro fertilization (IVF). Of the 143 female participants, 45 attended hatha yoga and 75 did not. Data suggest that psychological support and practice of hatha yoga before IVF is associated with distress reduction.11
Urinary incontinence
Yoga has been shown to reduce inflammation and may help improve symptoms of urge urinary incontinence. More research is necessary to demonstrate the effectiveness of yoga to reduce urge urinary incontinence symptom burden and improve quality of life.46
Weight management
A comparative controlled trial compared the effects of yoga and walking for weight management in overweight and obese adults.
Both groups showed a significant decrease in body mass index (BMI), waist circumference, hip circumference, lean mass, body water and total cholesterol. The yoga group increased serum leptin and decreased low-density lipoprotein (LDL) cholesterol. The walking group decreased serum adiponectin and triglycerides.49
Both yoga and walking improved anthropometric variables and serum lipid profile in overweight and obese persons.
The prevalence of yoga research in western health care is increasing. The marked increase in volume indicates the need for more systematic analysis of the literature in terms of quality and results.
