Health benefits of yoga

Health benefits of yoga
Scientific trials of varying quality have been published on the health benefits and medical uses of yoga. Studies suggest that yoga is a safe and effective way to increase physical activity and enhance strength, flexibility and balance. Yoga practice has also shown benefit in specific medical conditions, and we will look at this evidence and current scientific research below.

Scientists and medical doctors pursuing yoga-related research focus on its potential benefits as a technique for relieving stress and coping with chronic conditions or disabilities, as well as investigating its potential to help prevent, heal, or alleviate specific conditions, such as heart disease, high blood pressure, carpal tunnel syndrome, asthma, diabetes, and symptoms of menopause.7

1. Anxiety and depression
   Mind-body medical interventions are commonly used to cope with depression, and yoga is one of the most commonly used mind-body interventions. Systematic studies and meta-analyses have been carried out in order to assess the effectiveness of yoga for depression.

man and woman in a yoga pose
Yoga may be a promising way to reduce music performance anxiety and perhaps even prevent it in the future.
In one 9-week course of yoga, veterans were seen to experience significant reductions in anxiety, depression, and suicidal ideation. Mental health functioning scores were also improved, but pain intensity and physical health functionality did not show improvements.32

Elevated levels of cortisol (the stress hormone) are commonly seen in depression, and yoga has demonstrated an ability to relieve hypercortisolemia and reduce other parameters of stress. A study into the effects of yoga on cortisol and depression found that yoga might act at the level of the hypothalamus to create an 'anti-stress' effect by reducing cortisol levels, thereby helping to bring about relief in depression.33

A systematic review and meta-analysis investigating yoga for depression examined 12 randomized controlled trials, including 619 participants. The researchers concluded that despite the methodological drawbacks of the included studies, yoga could be considered an ancillary treatment option for patients with depressive disorders and individuals with elevated levels of depression.34

Professional musicians often experience high levels of stress, music performance anxiety (MPA), and performance-related musculoskeletal disorders (PRMDs). Given the fact that most professional musicians begin their musical training before the age of 12, it is important to identify interventions that will address these issues from an early age.35

Results from a study suggest that yoga may be a promising way for adolescents to reduce MPA and perhaps even prevent it in the future. These findings also suggest a novel treatment modality that potentially might alleviate MPA and prevent the early disruption and termination of musical careers.35

1. Arthritis
   A systematic review of 9 studies regarding yoga as a complementary approach for osteoarthritis found positive changes in psychological or physiological outcomes related to arthritis.

The studies varied in length and not all of the studies used randomized controlled design; many had small sample sizes, different outcomes, and used non-standardized yoga interventions. Despite these limitations, the reviewers concluded that yoga appears to be a promising modality for arthritis.48

1. Asthma
   In a study comparing people with asthma When comparing asthmatics in a yoga group and in a non-yoga control group with those in a control group, those in the yoga group had a significant improvement in a number of parameters suggesting improvements in symptoms of asthmas.

These parameters included an improvement in levels of the proportion of hemoglobin and the antioxidant superoxide, and a significant decrease was found in total leukocyte count (TLC) and differential leukocytes count in comparison to control group.15

The yoga group had more significant improvements in biochemical variables than the control group. Results show that yoga can be practiced as adjuvant therapy with standard inhalation therapy for a better outcome of asthma.15

However, a systematic review assessing the effectiveness of yoga as a treatment for asthma, concluded that there is insufficient quality evidence to support the belief that yoga alleviates asthma and that further, more rigorous trials are warranted.16

1. Balance and falls
   Falls amongst older people are a global health concern. Whilst falling is not a typical feature of aging, older people are more likely to fall and falls are a leading cause of death and disability.13

older people practicing yoga
Yoga has been shown to help improve balance and prevent falls in older adults.
Yoga and tai chi have shown potential to improve balance and prevent falls in older adults. They also have the potential to improve pain and quality of life.

In a 14-week program comparing yoga and tai-chi to usual care, yoga was associated with a slight decrease in the incidence of falls and a reduction in average pain scores in older adults. Although these changes were not statistically significant, the results showed positive changes to balance, pain and quality of life and a high level of interest through attendance amongst older participants.

The results support offering tai chi and yoga to older people who are frail and dependent with physical and cognitive limitations.63

Another study observing body balance and postural control in young adults determined that a 5-month hatha yoga training program could improve postural control significantly in healthy adults.14

1. Bipolar disorder
   In a study of the benefits and risk of yoga in individuals with bipolar disorder, the participants reported positive emotional effects, particularly reduced anxiety, positive cognitive effects (e.g., acceptance, focus, or "a break from my thoughts"), or positive physical effects (e.g., weight loss, increased energy). Some respondents considered yoga to be significantly life changing. The most common negative effect of yoga was physical injury or pain.36

Five respondents gave examples of specific instances where yoga practice increased their agitation or manic symptoms, while another five respondents gave examples of times that yoga increased depression or lethargy.

1. Breast cancer cognitive problems
   Survivors of cancer often report cognitive problems, and people undergoing cancer treatment often experience decreases in physical activity. Although physical activity benefits cognitive function in non-cancer populations, evidence linking physical activity to cognitive function in survivors of cancer is limited.40

A study comparing a group with and without yoga intervention found that those who practiced yoga more frequently reported significantly fewer cognitive problems at a 3-month follow-up compared to those who practiced less frequently.40

These findings suggest that yoga can effectively reduce cognitive problems in survivors of breast cancer and prompt further research on mind-body and physical activity interventions for improving cancer-related cognitive problems.

1. Breast cancer disability
   Secondary arm lymphedema continues to affect at least 20% of women after treatment for breast cancer, along with pain and restricted range of motion requiring lifelong professional treatment and self-management.41

A pilot trial was designed to investigate the effect of yoga on women with stage one breast cancer-related lymphedema. The 8-week yoga intervention reduced tissue induration of the affected upper arm and improved quality of life scores. Arm volume of lymphedema and extra-cellular fluid did not increase during the yoga intervention, but these benefits dissipated after the women stopped doing yoga, at which point arm volume of lymphedema increased.41

Additional research of a longer duration and with higher levels of lymphedema and larger numbers is warranted before definitive conclusions can be made.

1. Cancer-related fatigue
   Fatigue is one of the most frequently reported, distressing side effects reported by survivors of cancer and often has significant long-term consequences. Research indicates that yoga can produce invigorating effects on physical and mental energy, and thereby may improve levels of fatigue.

woman bending forward into yoga floor pose
Studies have suggested that yoga interventions may be beneficial for reducing cancer-related fatigue in women with breast cancer.
An 8-week yoga exercise program assessed whether yoga can decrease anxiety, depression and fatigue in patients with breast cancer. Fatigue was effectively reduced in the study but the intervention was not associated with a reduction in depression or anxiety.37

The authors of the study conclude that oncology nurses should strengthen their clinical health education and apply yoga to reduce the fatigue experienced by patients with breast cancer who undergo adjuvant chemotherapy.

Another 12-week study found that restorative iyengar yoga was associated with reduced inflammation-related gene expression in breast cancer survivors with persistent fatigue. These findings suggest that a targeted yoga program may have beneficial effects on inflammatory activity in this patient population, with potential relevance for behavioral and physical health.38

A systematic review of yoga interventions on fatigue in patients with cancer and survivors of cancer suggests that yoga interventions may be beneficial for reducing cancer-related fatigue in women with breast cancer; however, conclusions should be interpreted with caution as studies demonstrated varying levels of bias and inconsistent methodology.39