Sat Bir Singh Khalsa, a professor of sleep medicine at Harvard Medical School and a 50-year practitioner and longtime instructor of Kundalini yoga, has dedicated his life to spreading the word about the health and mental health benefits of yoga. 

“In contemporary medicine, physical medicine and psychology don’t really talk to one another. In yoga, it is all one; you cannot separate your mental health from your health,” Khalsa said at Sunday’s Monadnock Summer Lyceum at Peterborough Unitarian Universalist Church, which was the final event of the 2024 season. 

Abhai Raj Liewellyn and Gwir Huddleston Liewellyn performed music prior to the lecture. Peggy Cappy, a longtime local yoga instructor, was the moderator. Bob Beck was the coordinator. 

Khalsa spoke about the growing popularity of yoga in the past 20 years in the United States, with 17% of Americans, according to one study, reporting they had practiced yoga in the past year. Khalsa noted that the demographics of yoga, however, are still limited to mostly women, at about 70%, and to upper-income white people.

“The sad thing is, some of the populations who need the benefits of yoga the most, who have chronic stress and lifestyle induced-diseases, are not getting the benefits of yoga. It is necessary to get the research to prove that yoga is safe and efficacious, so schools and businesses can justify bringing it in,” Khalsa said. “In business settings, it’s the [return on investment] —does this help workers be more productive and healthier? We have proof that it does.”

Khalsa, who lectures internationally about the benefits of yoga, is the author of more than 80 scientific papers on the health and mental health benefits of the yoga through its ability to regulate the autonomic nervous system, which regulates involuntary physiologic processes including heart rate, blood pressure and respiration.

“Westerners first started becoming curious about Indian yogis – they were called ‘fakirs’ – in the 19th century, and about the rumors that the fakirs had the ability to stop their own hearts. When Westerners studies the fakirs, they learned that while they can’t stop their hearts, they can regulate and  slow their heart rates, which is not something Western medicine was familiar with,” Khalsa said. 

Khalsa notes that  there has been a “remarkable increase” in research on yoga, and that since 2022, researchers have completed 70 meta-analyses of the physiological effects of yoga, with conclusive proof that consistent yoga practice incorporating all four elements of yoga – postures,  breathing, mindfulness, and meditation – lowers stress and improves health as a result.

“The most-powerful and immediate affects of yoga is a relaxation response. Research has shown that the brain activity in people who meditate is different, and that their  brain structure actually changes over time with long-term yoga practice, ” Khalsa said. “American medicine is not succeeding in combating the effects of stress and the resulting poor lifestyle choices which cause disease.” 

Khalsa explained that the “mindfulness” component of yoga, which enables people to have a higher awareness of the internal and external processes affecting their bodies, causes people to make healthier lifestyle choices, including avoiding a sedentary lifestyle and unhealthy diet, and potentially addictive behaviors. 

“In contemporary medicine, we try to influence people with guilt and fear – don’t do this, don’t do that. But what happens to people who practice yoga as a lifestyle ? Their desire to change their lifestyle comes from deeper experiences that start to occur in their practice; they start to regulate their internal state.  They are more sensitive to what goes into their body and how they feel, so they make healthier choices, from the ground up,” Khalsa said.

For people who practice long term and integrate all four components of traditional yoga practice, Khalsa said the results are transformative.

“People feel peace and tranquility, then they achieve a  feeling of deep unity, of feeling one with the universe. People mostly have materialistic goals in this country – fame, money, possessions. But we know these things don’t make people happy. After committing to yoga practice, people will start to change their goals,” Khalsa said. “They want deeper experiences, leading to pure spirituality.”