Stand up for Health
Jacob Schor, ND, FABNO
November 6, 2014
Stand up and be healthier.
People were not made for sitting, at least not to the extent we do these days. The more time people spend sitting, the higher their risk is for heart disease, cancer and just plain dying.
Sitting around, what the science journals call sedentary behavior, is associated with increased cancer risk. An August 2014 meta-analysis, which combined date from 17 separate prospective studies to include a total of 857,581 participants, reported that sedentary behavior was significantly associated with a 20% increase in overall risk of cancer. This effect varied between cancer types with endometrial and lung cancer having the largest increases in relative risk (RR 1.28 and 1.27 respectively).
In 2010, data from 73 separate studies on life style and breast cancer were combined to see if sedentary behavior, spending too much time time in a chair was linked to breast cancer: the conclusion was that active women had a 25% lower breast cancer risk when compared to the least active women .
A 2012 study of 222, 397 Australians reported that sitting for 11 hours a day increases risk of dying during a 3-year study by 40% . If that sounds like a lot of time spent in a chair, think again. Consider an 8-hour desk job, plus sitting for meals, plus checking email, plus Netflix. Eleven hours is a piece of cake, albeit an unhealthy piece.
I’ve been standing in front of my desk, my computer propped atop a cardboard box, trying not to sit down in my comfy chair, ever since reading a paper by Sjögren et al published in October 2014 that looked at sedentary behavior. These researchers were looking at the effect exercise has on telomere length . Telomeres are the ‘caps’ at each end of a chromosome stabilizing the gene. Every time a cell divides, the telomeres get a tiny bit shorter. When the telomeres get too short that cell dies. All the telomeres in your body are slowly shrinking. Telomere length predicts your risk for chronic disease and cancer; it is the ultimate biomarker, the measure of how much lifespan a person has left. Shortening telomeres are the fundamental biomarker of aging . Preventing telomere shortening is the measure of any intervention that promises to improve health .
Sjögren measured telomeres in blood samples from a group of 49 overweight sedentary people before an after half of them took part in a six-month exercise program. Exercise helped them lose weight and lower cholesterol. Exercise did not lengthen telomeres. In fact, any increase in time spent exercising was associated with a trend toward shorter telomeres. This was a surprise .
Exercise after all, is supposed to be good for you. It’s supposed to make you feel younger, not older. What stood out in Sjögren’s data was that sitting made a significant difference, reducing time sitting was associated with increases in telomere length.
Telomere length by the way is a better predictor of heart disease than cholesterol. A July 2014 meta-analysis published in the British Medical Journal involving 43,725 people, reported that people with short telomeres were at greater risk of heart disease than people with longer telomeres, a 40 to 80% higher risk depending on the type of study .
This is somewhat sacrilegious to think but perhaps our current faith in the benefits of exercise is misplaced. The benefit of exercise may be that it reduces the time we spend sitting. Exercise may be good only because it gets us to stand up.
The passing of time and with it the repeated cell divisions are thought to be the main determinant why telomere length decreases but other things can hasten the process, in particular oxidative stress, inflammation, and psychological stress . Rigorous exercise increases inflammation an oxidative stress so we shouldn’t be surprised that it may shorten telomeres.
We don’t fully understand this business yet. For example regular physical activity reduces risk of some age-related chronic diseases such as cardiovascular disease, cancer, and type II diabetes . Yet this isn’t the first study to suggest exercise shortens telomeres, in particular extreme exertion .
Some studies report positive associations between physical activity and telomere length. One reported that increased physical activity was associated with increased telomere lengths equal to a 10-year decrease in biological age between active and inactive subjects . These differences are quite pronounced in some studies; for example, ultra-marathon runners compared to sedentary individuals have telomeres that suggest the runners are 16-years younger than their actual age . These studies might be interpreted the other way around, not that exercise makes us younger, but that sitting makes us older, or that people who feel older sit more and don’t run marathons.
Several studies report a sweet spot between too little and too much physical activity; moderately active people have longer telomeres compared to both sedentary and extremely active people. It looks safest to be in the middle of the pack, neither exercising too little or to rigorously .
Patients are by rule rather impatient when it comes to wanting advice, saying more and better studies are needed before forming an opinion does not suffice. Here is what I am telling my patients. Exercise continues to be good for you. Being fit and staying fit as you age should be your goal. The transition from couch potato to fit though does take a toll on the body over the short term. Perhaps using herbs with anti-inflammatory and oxidant quenching action may help. A reduction in time spent sitting is the target.
This author spends a good portion of his workday sitting speaking with patients and then compounds the problem by spending free time sitting reading. This is a big problem. His attempts to counter such a sedentary lifestyle with exercise apparently do little to counter the overall effects of his sedentary life at shortening telomere length and possibly lifespan. Those quick workouts at the gym he was feeling so proud about may not help either.
The easiest approach may be to simply stand up more. This article was written standing at a work desk. Standing while writing takes a little getting used to at first, but it fast becomes a new habit. If it keeps those telomeres happy, there is no reason for complaint; it’s worth the effort.
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