Does Sitting Cause Cancer?
February 13th, 2014 by Holly Cornish
No doubt you saw the buzz-phrase last year that “sitting kills” — a phrase meant to scare you into overhauling your sedentary lifestyle in hopes of adding years to your life.
I thought today we’d take a look at the logic behind leveling a murder charge against sitting. Is it dangerous to merely sit too much? The evidence suggests it is. And the amazing thing is, all you have to improve your health is stand up! Here’s what I found. . .
In a 1950s study of bus conductors who stand versus bus drivers who sit, those who stood had roughly half the risk of developing heart disease. Similarly promising results were found in a recent UK study where volunteers who normally sit all day were asked to stand up for three hours a day.
Thanks to a combination of glucose monitors, heart rate monitors, and accelerometers, measurements revealed that, following a meal, blood glucose levels fell back to normal much faster on the days when the volunteers stood. Plus, they burned a lot more calories—about 50 an hour. Add that up over a years’ time and it amounts to saving 8 lbs of fat.
We sit too much. . .
According to BBC News, a recent survey showed that most of us spend up to 12 hours of every day sitting on our backsides. Considering all the screen-based entertainment and work obligations, from computers to tablets to phones to television, it’s not surprising. Add in the average seven hours a day most people spend sleeping, and you’re sedentary 19 hours a day.
Some studies show that sitting is so bad for us, it cuts our longevity by two years. And you can’t necessarily combat it with regular exercise. That helps, sure, but prolonged sitting is damaging in ways that can’t be undone.
If you’re wondering why sitting is so bad, you have to look at how sugar comes into play. Sitting changes the way your body metabolizes sugar, meaning the way it breaks food down into glucose that gets moved through your bloodstream to other cells. Your body is more efficient at doing this when you’re more active.
Sitting’s effect on sugar metabolism is especially relevant to cancer. Cancer has a “sweet tooth,” as long-timer readers of this newsletter know. Dr. Patrick Quillin wrote about the concept that sugar feeds cancer over 14 years ago in an issue of Nutrition Science News.
When it comes to virtually any cancer, blood glucose is the preferred fuel. Take sugar out of the picture and most cancer patients see their tumors slow and their prognosis improve.
But sitting does more than
just raise your blood sugar
Prolonged sitting also reduces the activity of the enzyme lipoprotein lipase. That the substance your body uses to break down fats so they’re available as fuel to your muscles. Reducing this enzymatic activity means you develop elevated triglycerides and fats, incur an increased risk of heart disease, and experience a general sluggishness that leads to less and less physical activity.
The bottom line here is that simple movements, like standing a few hours a day, help keep your blood-sugar under control. And with your blood sugar under control over the years to come, your risk for several debilitating diseases—cancer among them—plummets nicely.
Simple ways to gain this benefit include pacing while you’re on the phone, opting for a standing table at a coffee shop, or setting a timer every time you sit down to remind yourself to get up and move around at least every half hour.
There are also standing desks you can invest in. Or, simply make it a goal to stand whenever possible. A good way to look at it is that the total number of hours spent sitting aren’t as damaging as the number of consecutive hours spent sitting.
Your goal should be to interrupt your sedentary time as often as possible. Do that and you’ll gradually lower your blood sugar, in turn lowering your risk of a number of diseases including cancer.
By the way, I’m not saying that standing up is your first line of defense against high blood sugar! You also need to get most or all sugar out of your diet, and most carbohydrates as well. A number of supplements can help control blood sugar, too. But just standing up does help.
Quite a bit of evidence shows cancer is sensitive to blood-glucose levels. One four-year study in the Netherlands found cancer risk more than doubled when sugar intake was high. In other studies, sugar intake has been shown to be a strong risk factor for breast cancer.
High blood sugar levels over a long period of time translate to a slew of health issues, including diabetes, heart attack, stroke, blindness, nerve damage, kidney failure, gum disease, and even tooth loss.
Lee Euler, Publisher