It took just 17 weeks of simple yoga asanas — including breath exercises, stretching poses, pranayama and meditation — to decrease stress, improve concentration as well as lower body weight and other metabolic parameters in 2,000 school-going adolescents, all of them aged between 13 and 15. What’s more, the regime inculcated the habit of 40 minutes of physical activity as part of the school routine itself, something that is being seen as the first step to prevent chronic illnesses. These are the findings of a new study conducted by the Madras Diabetes Research Foundation, which was funded by the Indian Council of Medical Research (ICMR), involving students of 24 public and private schools in Delhi and Chennai.
The sessions were held in the school premises once a week by trained instructors. A total of five awareness talks on healthy lifestyle and nutrition were delivered once a month to the group. “We developed an Adolescence Stress Scale (ADOSS) factoring in salivary cortisol, metabolic and clinical parameters and a Letter Cancellation Test (LCT). We found a five per cent reduction in stress levels. But while our main focus was stress and cognitive ability that’s crucial to students at that age as they prepare for competitive exams, we were pleasantly surprised by improvement in metabolic markers. There was a significant reduction in body weight, fat, waist circumference, BMI, systolic and diastolic blood pressures among students in a short time from when they began the yoga sessions. The salivary cortisol in the yoga group participants decreased too. These parameters increased in the non-yoga group,” says lead author Dr Ranjani Harish. “LCT scores, which are a measure of attention span and concentration, increased by 18 per cent in the yoga group as compared to seven per cent in the non-yoga group. All these changes persisted when analysed by sex, school type and site,” she adds.
WHY IS THIS STUDY SIGNIFICANT?
According to Dr V Mohan, President, MDRF, “The study is significant because it highlights that pranayama can help teens manage their turbulent growth years and stress that can manifest as a metabolic syndrome in later years. And this is an easy preventive practice to follow.”
“Adolescence is one of the most critical periods of transition between childhood and young adulthood during which young people experience physiological, hormonal cognitive and social changes. These build up stress and globally one in seven among 10 to 19-year-olds experience some sort of mental health issues. Earlier studies report that the prevalence of stress among Indian adolescents varied between 13 and 45 per cent. Adolescent stress is the most common cause of obesity which leads to diabetes especially when you factor in pubertal and hormonal influences, particularly among girls. This study shows that there can be a long-term risk reduction model though the study did not look at diabetes as an outcome,” says senior author Dr Anjana Ranjit Mohan.
WHICH PRACTICES WORKED FOR THE YOGA CAPSULE
The yoga protocol of 40 minutes is a tight capsule of breath patterns and stretching before ending with meditation. “Supportive studies show that 21 days of Hatha yoga reduced 4.3 per cent of perceived stress scores in intervention participants. Another study conducted in 60 adolescents in the 12–17 age group showed reduced stress scores by 17.2 per cent because of the practice of Pranayama. A study conducted in 10th grade students showed how those who practised Yoga Nidra for 21 days reduced stress scores from moderate to low. Various forms of pranayama such as Nadishuddi Pranayama (alternate nostril breathing), Kapalabathi Kriya (cleansing breath), Sitali and Sitkari Pranayama have been known to decrease blood pressure. We observed that the mean systolic and diastolic blood pressure were reduced significantly in the yoga group participants. The practice of yoga decreased systolic (4 mmHg) and diastolic (2 mmHg) blood pressure among participants,” says Dr Ranjani Harish. “The metabolic benefits are huge and very sustainable because this 40-minute routine is a full-body rev-up that leaves students sweating by the end of the session. At a time when the benefits of a 40-minute exercise capsule are being recommended as a preventive healthcare regime, this builds the habit early,” she adds
Both the authors believe that their peer-led training model, where they trained yoga and science teachers for supervising these sessions, can easily be taken forward, involving more teachers and even student representatives.
PROVEN BENEFITS OF YOGA
Persistent surges of stress hormones, including adrenaline and cortisol, are known to damage blood vessels and elevate blood pressure.
A 2017 study by the US-based Tulane University School of Public Health and Tropical Medicine, had similar results. It had found that a school- based yoga practice for eight weeks improved their well-being and emotional health. A 2016 study had shown how people who practised yoga regularly had low cortisol levels. A meta-analysis the same year found Hatha yoga helped control anxiety among test subjects. Another study by the Boston University School of Medicine in 2010 had demonstrated that yoga improved mood and anxiety levels more than walking. The researchers suggest that this was due to higher levels of the brain chemical gamma-aminobutyric acid (GABA). The researchers tested GABA activity and found that yoga increased GABA levels in the participants.
