Winter has come to the Great Lakes, no matter what the calendar says. This morning I walked out the door to take out the trash and the cold took my breath away. I warmed up the car while I had breakfast, perhaps not the most environmentally friendly practice, but...
On my way to work, depending on my mood, I listen either to CBC Radio 2 or NPR. This morning it was Morning Edition, a choice I regret. This morning's health story was a credulous pile of poorly researched word salad about yogic breathing practices.
Yoga is very popular in these parts, and folks seem to love it. According to my sources, it's both relaxing and a good workout. According to NPR's story, though, it's much more. We'll skip over the poor reporting aspect of this story, except to note that the reporter did not ask any pointed, skeptical questions, and didn't question any of the underlying assumptions and claims made by the people she interviewed. And what were these claims and assumptions?
There are plenty of ways to relieve stress — exercise, a long soak in a hot bath, or even a massage. But believe it or not, something you're doing right now, probably without even thinking about it, is a proven stress reliever: breathing.
As it turns out, deep breathing is not only relaxing, it's been scientifically proven to affect the heart, the brain, digestion, the immune system — and maybe even the expression of genes.
This sounds pretty far-fetched, but let's see what they are actually talking about.
Mladen Golubic, a physician in the Cleveland Clinic's Center for Integrative Medicine, says that breathing can have a profound impact on our physiology and our health.
"You can influence asthma; you can influence chronic obstructive pulmonary disease; you can influence heart failure," Golubic says. "There are studies that show that people who practice breathing exercises and have those conditions — they benefit."
The reporter then talks to an instructor of pranayama---traditional yogic breathing---who describes some common techniques.
Research has shown that breathing exercises like these can have immediate effects by altering the pH of the blood, or changing blood pressure
OK, hold it right there. Let's examine these first claims. Breathing is part of the way we regulate our body's pH (acidity). Our body only functions within a very narrow pH range centered on the slightly basic 7.40. Various insults to the body, such as overwhelming infection, can disturb the pH, and the kidneys help regulate this in the long term, but brief corrections can be made by the lungs. The lungs, in addition to absorbing oxygen, help dispense with carbon dioxide. Carbon dioxide acts as an acid in the body, so rapid or deep breathing removes acid, raising the blood's pH. The ability of the lungs to do this is quite limited, no least by the fact that blowing off acid consumes a lot of energy, and patients can tire, and then stop breathing completely. Almost all alternative health claims that talk about pH and "acidity" are complete bunk.
That breathing techniques might lower blood pressure isn't far-fetched but it's unclear to me what clinical utility there is to briefly lowering blood pressure this way. The piece goes on to make certain claims about being able to calm oneself with breathing techniques, which sounds like a good idea, but once again, I'm underwhelmed with what long-term clinical impact that might have.
But the real problem comes at the end of the piece.
In his new book, Relaxation Revolution, Benson claims his research shows that breathing can even change the expression of genes. He says that by using your breath, you can alter the basic activity of your cells with your mind.
"It does away with the whole mind-body separation," Benson says. "Here you can use the mind to change the body, and the genes we're changing were the very genes acting in an opposite fashion when people are under stress."
This "whole mind-body separation" problem is not unknown to the rest of us---most real doctors understand that the brain and the rest of the body are interdependent. The real problem here, though, is this idea that yogic breathing somehow changes the basic fabric of our being, our genetic instructions. There are some very important distinctions that were blurred here. First, there is the difference between "genes" and "gene expression", a difference which Dr. Benson surely knows. Genes are nucleic acids that encode instructions for making proteins. Genes can be actively coding for these proteins, or can be "turned off" either permanently, or temporarily based on signals from feedback loops and other stimuli. For example, if you drink a lot of milk, it's worth the energy expenditure for you to make lactase, the enzyme that helps digest milk sugars. If you don't drink milk, it would be wasteful to make lactase, and the gene can be shut down.
So it's not beyond the pale to imagine that various stimuli can have an affect on gene expression (but no on the genes themselves). The question becomes is there truly a measurable effect, and does that putative have any clinical significance (beyond lining the pockets of the author). I was able to find one recent article that took a very small sample of patients who had leukemia, and made certain measurements of gene expression. While intriguing, the results are clinically irrelevant.
I said I wouldn't harp on the reporting, but I have learned to expect more from NPR. This wasn't reporting, it was an infomercial.
Kumar, A., & Balkrishna, A. (2009). To study the effect of the sequence of seven pranayama by Swami Ramdev on gene expression in leukaemia patients and rapid interpretation of gene expression Journal of Clinical Pathology, 62 (11), 1052-1053 DOI: 10.1136/jcp.2008.061580
Raghuraj P, Nagarathna R, Nagendra HR, & Telles S (1997). Pranayama increases grip strength without lateralized effects. Indian journal of physiology and pharmacology, 41 (2), 129-33 PMID: 9142556
Pramanik, T., Sharma, H., Mishra, S., Mishra, A., Prajapati, R., & Singh, S. (2009). Immediate Effect of Slow Pace on Blood Pressure and Heart Rate The Journal of Alternative and Complementary Medicine, 15 (3), 293-295 DOI: 10.1089/acm.2008.0440
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KOCHUPILLAI, V. (2005). Effect of Rhythmic Breathing (Sudarshan Kriya and Pranayam) on Immune Functions and Tobacco Addiction Annals of the New York Academy of Sciences, 1056 (1), 242-252 DOI: 10.1196/annals.1352.039