Health Improvements Via Self-Generated Positive Emotions

Health Improvements Via Self-Generated Positive Emotions 

By Kim Byrd-Rider

            The vagus nerve is the core component of the parasympathetic nervous system (PNS) and is the central player of Porges’s Polyvagal Theory (2007). The theory demonstrates positive correlations between 1. positive emotions and affect, 2. high vagal tone and 3. perceived positive social connections. Each influences the other in an upward positive spiral, improving physical health (Kok & Fredrickson, 2010). The vagus nerve links to nerves coordinating eye gaze, facial expressions and tuning into human voices (Porges, 2007). High vagal tone is associated with prosocial behavior (Fabes, Eisenberg, & Eisenbud, 1993) and social closeness (Kok & Fredrickson, 2010). Vagus nerve tone reciprocally increases form intranasal oxytocin produced by positive social engagement (Kemp et al., 2012).  The practical question is: What interventions kick start the positive movement of any of the three to encourage the positive upward spiral of all three? 

This investigation begins with 2. high vagal nerve tone, because it can be measured quantifiably. The 10th cranial nerve (the vagus nerve) registers low tone when the “fight or flight” sympathetic nervous system (SNS) operates and high tone when the PNS operates. Together the SNS and PNS are the autonomic nervous system, which is responsible for unconscious bodily functions like breathing, heart rate and digestion. 

A multitude of studies connect high vagal nerve tone (PNS) to protective factors of the immune system for improved health (Kok, Coffey, Cohn, Catalino, Vacharkulksemsuk, Algoe, … & Fredrickson, 2013). For example, human natural killer cells “eat” cancer, bacteria and virus cells.  Cortisol, a hormone increased by the SNS, “eats” natural killer cells belonging to the immune system.  Thus, low tone vagal activity lowers the amount of natural killer cells fighting for the immune system (Diego, Field, Sanders, & Hernandez-Reif, M.,2004; Brittenden, Heys, Ross, & Eremin, 1996). Low vagal tone also forecasts high inflammation (Thayer & Sternberg, 2006), myocardial infarction risk and lower survival odds after heart failure among other poor health outcomes (Bibevski & Dunlap, 2011). 

A research study (Kok, 2013), took advantage of known vagal tone outputs for it’s quantifiable measurements. High-frequency components (0.12-0.4 Hz) of the heart rate signal reflect vagal influences on the heart. Once considered stable and unchanging, vagal nerve baseline can indeed be changed (Kok, 2013). To prove this, researchers used 71 university faculty/staff and one intervention to test the baseline of the vagus nerve. For six weeks, subjects performed a mandatory one-hour per week loving-kindness meditation. Plus, they self-decided frequency and duration of daily meditations. Baseline vagal nerve tone was taken two weeks before the intervention and one week after. The baseline vagal tone was higher post intervention (Kok, 2013). Increasing 2. vagus nerve tone and 3. positive social engagement are reciprocally influenced by self-generated 1. positive emotion, as in the Kok study (2013). Of the three, the easiest variable to manipulate for interventions is 1. positive emotion because it can be self-generated. 

New interventions are needed to self-generate positive emotions. Exercise interventions like aerobics and weight lifting require increases of SNS to increase heart rate, so low vagal tone (SNS) is associated with exercise and stress.  (Lucas, Heidi, Porges, & Rejeski, 2016). While cardio-vascular exercises have great benefits, they cannot be used as an intervention for a high tone vagal goal. There is the established “fake it until you make it” approach, which has psychological journal evidence (Ekman, 1992). For example, a person smiles even though he doesn’t feel like smiling and eventually he becomes happier. Also, three additional interventions to meditation show great promise: yoga, tai chi and massage therapy. Even in rigorous yoga and tai chi exercises the nervous system alternates from SNS to PNS promoting efficient shifting from arousal to calm (Lucas, 2016) leaving the practitioner with a higher vagal tone baseline post intervention (Sullivan, 2018).  Autonomic neural regulation, the ability to change from SNS to PNS reciprocally, links to improved breast and prostate cancer outcomes (Magnon, Hall, Lin, et al., 2013; Couck, Marechal, Moorthamers, Laethem, & Gidron, 2016). In a systematic review of 71 journal articles (Riley & Park, 2015), yoga improved positive affect, mindfulness and self-compassion with positive changes in the posterior hypothalamus, interleukin-6, C-reactive protein and decreasing cortisol levels. Yoga also raises vagal tone (Sullivan, Erb, Schmalzl, Moonaz, Noggle,… & Taylor 2018) as does massage therapy (Hernandez-Reif, Field, Ironson, Beutler, Vera, Hurley,… & Hernandez-Reif, M., 2005a; Hernandez-Reif, Ironson, Field, Hurley, Katz, Diego,… & Burman, I., 2004b). Research on tai chi shows high tone vagal activity, as well (Wei, Li, Yue, Ma, Chang, Yi,… & Zuo, 2016). 

Each intervention requires different senses which means different brain processing pathways are activated and strengthened to achieve high vagal tone (Kayser & Shams, 2015). For example, yoga and tai chi require muscle movement, balance and eyesight brain processes. Sitting meditations and massage do not. Breath regulation, which directly effects the vagus nerve (Song, Liu, Proctor, & Yu, 2015), is required by all four interventions but at different tempos and efforts requiring different neuro-pathways (Kayser, 2015).  Yoga and massage researchers hypothesize the increase in vagal tone comes from pressure on the skin receptors (also part of the vagus nerve system) unlike tai chi and meditation (Hernandez-Reif, 2004b; Hernandez-Reif, 2005a). Combining the four interventions of yoga, meditation, massage therapy and tai chi may have cumulative health benefits due to their differences.  Research on this topic has not been done, yet. 

The key to finding more positively influential interventions may be to look at what the known interventions all have in common and then find similarly structured interventions. All four require the combination of the mind fixated in the present, body movement attention (either in controlled patterns or stillness) and breath regulation (whether high or low). 

Created by ancient people centuries ago, yoga, meditation, massage therapy and tai chi produce the appropriate stimuli combination for vagus nerve plasticity and brain plasticity to improve physical health. Few interventions match these criteria. Sports taught with a high level of mindfulness might qualify. American coaches and trainers would need to change their styles from win and push harder to focus intensely, regulate intensely, and recover frequently to a peaceful (PNS) state. The highest level athletes discover ‘the zone’ of focus and regulation on their own but most sports do not coach the previous approach. Yoga, meditation and tai chi are simple, adaptable and can be free. Minimal space, no equipment, no special floors, no shoes and no supervision are required, making them the optimal intervention choice to support 1. positive emotions and affect, 2. high vagal tone and 3. perceived positive social connections, for now. 

References 

Beckes, L., & Coan, J. A. (2011). Social Baseline Theory: The role of social proximity in emotion and economy of action. Social & Personality Psychology Compass, 5, 976–988 

Bibevski, S., & Dunlap, M. E. (2011). Evidence for impaired vagus nerve activity in heart failure. Heart Failure Reviews, 16, 129–135. 

Brittenden, J., Heys, S. D., Ross, J., & Eremin, O. (1996). Natural killer cells and cancer. Cancer, 77(7), 1226-1243. 

Couck MD, Marechal R, Moorthamers S, Laethem JL, Gidron Y (2016). Vagal nerve activity predicts overall survival in metastatic pancreatic cancer, mediated by inflammation. Cancer Epidemiol, 40, 47-51. 

Diego, M. A., Field, T., Sanders, C., & Hernandez-Reif, M. (2004). Massage therapy of moderate and light pressure and vibrator effects on EEG and heart rate. International Journal of Neuroscience, 114(1), 31-44. 

Ekman, P. (1992). An argument for basic emotions. Cognition & emotion, 6(3-4), 169-200. 

Fabes, R. A., Eisenberg, N., & Eisenbud, L. (1993). Behavioral and physiological correlates of children’s reactions to others in distress. Developmental Psychology, 29, 655–663. 

Harris, A. R., Jennings, P. A., Katz, D. A., Abenavoli, R. M., & Greenberg, M. T. (2016). Promoting stress management and wellbeing in educators: Feasibility and efficacy of a school-based yoga and mindfulness intervention. Mindfulness, 7(1), 143-154. 

Hernandez-Reif, M., Field, T., Ironson, G., Beutler, J., Vera, Y., Hurley, J., … & Hernandez-Reif, M. (2005a). Natural killer cells and lymphocytes increase in women with breast cancer following massage therapy. International Journal of Neuroscience, 115(4), 495-510.