Nudge

Here’s a surprising story from the San Diego International Airport.  For 10 non-consecutive days, signs were posted at the bottom of a set of stairs and escalators urging people to take the stairs.  The signs read: ‘Please reserve the escalator for those who need it’, or ‘Don’t lose time, lose weight. Use the Stairs’, or ‘Don’t waste Time, trim your Waistline. Use the Stairs’, or ‘You’ll get more stares if you use the stairs’, or ‘If you want to feel younger, act younger. Step it up! Use the stairs.’  On alternating days there were no signs posted. 

Researchers from the San Diego State University counted how many people took the stairs versus the escalator on days with and without the signs, and also interviewed people atop the stairs about their health and level of physical activity.  The research was headed by John Bellettiere, at UC San Diego, who is working on ways to help people sit less and move more.   On days when one of the signs was present, about twice as many people took the stairs compared to a no-sign day.  An important finding was that people who never exercised also used the stairs. People used the stairs even if they were in a rush and carrying luggage.  Bellettiere concluded that having even a small amount of exercise early in the day may lead to getting more later.  When people see others taking the stairs they are more likely to do so themselves, creating a ripple effect. 

Social science research has shown that there are many ways we can be ‘nudged’ into acting in ways that may be positive, or negative, for our well being.  Some utility companies get people to conserve power by sending out comparison notices, telling people how their use compares to others in the area who are using less.  This is a carefully designed strategy encouraging people to use less energy, and it has been successful.  If we believe other people are doing the right thing, we will want to do so also. The approach originates from the sociological concept of social norms, which holds that group members will respond to appropriate – or inappropriate  - values and behaviors held by others in their group.  The recent  Nobel Prize winner in Economics, Richard Thaler, wrote about these ideas in a book with Harvard lawyer Cass Sunstein – titled Nudge.  They consider their concepts to be from neither left nor right on many hot button issues, since a nudge does not restrict freedom of choice.

Be on the lookout for ways you are being subtly nudged by the culture around you.  Candy at the checkout counter at Safeway.  Signs urging you to walk up the stairs.  Wait a minute – that’s a good one.  Think of ways you can nudge yourself in a beneficial direction to exercise more.  Form a walking group; tell your friends what you plan to do; pay money to join a gym; write signs in your house that will inspire you to move, eat healthy food, or reach out to friends. 

Sadja Greenwood, MD, MPH  back issues on this blog

Your Microbiome has Circadian Rhythms

We humans have internal clocks; we experience daily changes in our energy, mood, appetite  and sleepiness based on time of day, light and dark, temperature and sleep patterns. These changes are known as circadian rhythms. Microbes in our gut, the so-called ‘microbiome’, have also been found to have circadian rhythms. Our gut bacteria make small rhythmical movements throughout the day and night. In so doing they impact our physiology and affect tissues far away from the gut, such as the liver.  Gene expression in the liver can change in tandem with the microbiome’s rhythm changes, resulting in variations in important liver functions, such as drug metabolism and detoxification. 

The new findings in a paper from the Weizmann Institute of Science in Israel, published 12/1/16 in the journal Cell, show that our circadian rhythms are deeply dependent on the oscillations of the gut microbes. Some of our daily rhythms are maintained but others are disrupted.  Previous work by the authors of this study, Eran Elinay and Eran Segal, showed that disrupting feeding times and sleep-wake patterns in mice induced changes in the gut microbiome.  Understanding more about this relationship could eventually help to find ways to intervene in obesity and it’s related metabolic problems, which are more common when circadian rhythms are disrupted due to shift work or jet lag.  Also, since most drugs, from Tylenol to chemotherapy, are metabolized by the liver, a better understanding of gut/liver rhythms could affect how and when medications are taken or given. According to Eran Segal “What we learned from this study is that there’s a very tight interconnectivity between the microbiome and the host.  We should think of it as one supraorganism that can’t be separated.  We have to fully integrate our thinking with regard to any substance we consume.” 

A take-home lesson from this study is that we should become more aware of our daily patterns of eating and sleeping, and try to keep them as regular as possible.  Eating during the day and letting the gut rest at night is desirable.  Also, remember that your gut microbiome thrives on the fiber found in vegetables and fruits. Think of yourself as a ‘supraorganism.’ !

Sadja Greenwood, MD, MPH  back issues on this blog

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