I interrupt my yoga nidra obsession to look at a paper that is literary hot off the press; and, more excitingly, is published by my former home, Nature Reviews (for those not in the know, the most prestigious scientific review journals, not that I am, ahem, biased or anything!). This Comment article* looks at yoga in the context of cardiovascular disease (CVD) – and guess what, it looks like it has potential.
The main CVD benefit is the reduction of stress
Yeah, we all know stress is bad for us but I don’t think we really appreciate the damage it has to our bodies. When we are stressed, our bodies go into sympathetic mode – that’s fight or flight mode – which means that:
- We produce high levels of hormones like cortisol and glucagon, to get the body up and going, in ‘flight’ from danger
- We produce high levels of the molecules that drive inflammation in our bodies (called pro-inflammatory cytokines)
- Our heart rate is faster, which means more work for the muscles in our hearts to keep it up
- The red blood cells that are involved in blood clotting, called platelets, start to form clusters (which, in the context of CVD, can put us at risk of blood clots)
Yoga helps to fight the stress
Many of us will have felt the benefits of yoga in reducing our stress levels (I’m pretty neurotic as it is, I don’t want to know how bad I would be without!).
Indeed, yoga has been shown to tackle pretty much all of the stress challenges I list above and help bring our sympathetic and parasympathetic systems in balance. Woop!
What about actual effects on CVD?
There is a growing body of evidence showing that yoga could really help in both preventing CVD and supporting those who have experienced a CVD episode. Some examples pulled out from the article:
- Yoga led to improved outcomes for those at risk of CVD, including improvements in blood pressure, heart rate and cholesterol levels, when compared with standard of care (ie the way this would usually be managed in a clinical setting) or no intervention – this is from a systematic review and meta-analysis** looking at 44 randomised controlled trials
- In patients with atrial fibrillation (or AF; a CVD characterised by irregular heartbeats and increased risk of stroke), yoga-based interventions led to fewer AF episodes, improvements in blood pressure, mental health and general quality of life
- In patients who had already experienced a heart attack, a rehabilitation programme that included yoga led to improvements in self-rated health after 12 weeks compared with standard of care (although it wasn’t able to show statistically significant improvements in preventing cardiac events for re-occurring)
What does this mean?
We definitely need more evidence and better-designed, more powerful studies – which is challenging given the lack of funding for yoga studies.
But the research so far is promising! Including a yoga-based intervention as a preventative measure or rehabilitation measure is cheap and easy, and the benefits could be huge for those impacted by CVD. Plus, extra bonus point, all the yoga interventions included some sort of relaxation element, which to me suggests that yoga nidra too could be a great supplement in CVD.
*A Comment article is a short article that summarises the existing published literature and puts forward a comment or hypothesis.
**A systematic review and meta-analysis is one of the most powerful types of studies, as it looks at all the existing literature and collates their findings and re-analyses them to be able to draw broader conclusions.