Tag Archives: Northwestern University

Take a hike

The lure of “the gym” has always escaped me. I’ve joined a few fitness centers in my day, but I consistently end up abandoning the gym and resorting to my preferred route to fitness: walking. Whenever possible, I walk and hike in the great outdoors.

A host of recent studies has validated my faith in the benefits of walking. And some of these benefits may surprise you.

First, being active is better for your health. Duh. We’ve all suspected that for a long time. But here’s a new finding: sitting may be the real problem. Studies show that the more you sit, the greater your risk for health problems. In a study of more than two thousand adults ages 60 and older, every additional hour a day spent sitting was linked to a 50 percent greater risk of disability. Even those who got some exercise but were sitting too much were more likely to get dumped in the pool of disabled people.

Dorothy Dunlop and her colleagues at Northwestern’s McCormick School of Engineering and Applied Science concluded that sitting seems to be a separate risk factor. Getting enough exercise is important, but it’s equally important not to be a couch potato the rest of the time. Their study appeared in the Journal of Physical Activity & Health in 2014.

Another study, published in Medicine & Science in Sports & Exercise, noted something else about prolonged sitting: taking “short walking breaks” at least once an hour may lessen or even prevent some of the adverse effects, especially on the cardiovascular system. When healthy young men sat for 3 hours without moving their legs, endothelial function—the ability of blood vessels to expand and contract—dropped significantly from the very beginning. But when they broke up their sitting time with slow 5-minute walks every 30 or 60 minutes, endothelial function did not decline.

Here’s another benefit: Exercise, including walking, can keep you from feeling depressed. A British study, reported in JAMA Psychiatry, followed over 11,000 people (initially in their early 20s) for more than 25 years. It found that the more physically active they were, the less likely they were to have symptoms of depression. For example, sedentary people who started exercising 3 times a week reduced their risk of depression 5 years later by almost 20 percent. The researchers concluded that being active “can prevent and alleviate depressive symptoms in adulthood.”

Ready for one more reason to walk? A study described in The Wall Street Journal in 2014 found that walking can significantly increase creativity. This is a brand new finding. In the past, studies have shown that after exercise, people usually perform better on tests of memory and the ability to make decisions and organize thoughts. Exercise has also been linked anecdotally to creativity: writers and artists have said for centuries that their best ideas have come during a walk. But now science supports that link.

Researchers at Stanford University, led by Dr. Marily Oppezzo, decided to test the notion that walking can inspire creativity. They gathered a group of students in a deliberately unadorned room equipped with nothing more than a desk and a treadmill. The students were asked to sit and complete “tests of creativity,” like quickly coming up with alternative uses for common objects, e.g., a button. Facing a blank wall, the students then walked on the treadmill at an easy pace, repeating the creativity tests as they walked. Result: creativity increased when the students walked. Most came up with about 60 percent more “novel and appropriate” uses for the objects.

Dr. Oppezzo then tested whether these effects lingered. The students repeated the test when they sat down after their walk on the treadmill. Again, walking markedly improved their ability to generate creative ideas, even when they had stopped walking. They continued to produce more and better ideas than they had before their walk.

When Dr. Oppezzo moved the experiment outdoors, the findings surprised her. The students who walked outside did come up with more creative ideas than when they sat, either inside or outside, but walking outside did not lead to more creativity than walking inside on the treadmill. She concluded that “it’s the walking that matters.”

So a brief stroll apparently leads to greater creativity. But the reasons for it are unclear. According to Dr. Oppezzo, “It may be that walking improves mood,” and creativity blooms more easily when one is happier. The study appeared in The Journal of Experimental Psychology: Learning, Memory, and Cognition in 2014.

In truth, I don’t need these studies to convince me to keep walking. It helps that I live in San Francisco, where the climate allows me to walk outside almost every day. Walking is much more challenging when you confront the snow and ice that used to accompany my walks in and around Chicago. So I’m not surprised that walkers in colder climes often resort to exercising indoors.

It also helps that San Francisco has recently been voted the second most walkable city in America. According to Walk Score, an organization that ranks the “walkability” of 2,500 cities in the U.S., SF placed just behind New York City as the most walkable major American city.

SF’s high score is especially impressive in light of the city’s hills. Although I avoid the steepest routes, I actually welcome a slight incline because it adds to my aerobic workout. Why use a Stairmaster in a gloomy gym when I can climb uphill enveloped in sunshine and cool ocean breezes?

But whether you walk indoors or out, do remember to walk! You’ll assuredly benefit health-wise. And you just may enhance your creativity quotient. Someday you may even find yourself writing a blog like this one.

Beavers? Seriously?

Here’s a piece of news to chew on. A recent study of beavers’ teeth may lead to decay-resistant teeth for humans.

Although beavers never brush their teeth, and they certainly don’t drink fluoridated water, their teeth are protected from tooth decay by the iron that’s part of the tooth’s chemical structure.

If you looked at a beaver’s teeth, you’d notice that their iron-rich coating gives the teeth a reddish-brown or orange color. Apparently orange is the new white.

Researchers found that the pigmented enamel on beavers’ teeth is both harder and more resistant to acid than human tooth enamel, even when treated with fluoride. This discovery could lead to a better understanding of human tooth decay, as well as improvements in current fluoride treatment.

Tooth decay in humans is a major public health problem, even in this era of fluoride treatments. The American Dental Association estimates that dental care in this country costs $111 billion a year, and much of it is spent on cavities and other tooth-decay issues. According to the World Health Organization, up to 90 percent of children and nearly 100 percent of adults worldwide have or have had cavities.

The research team, led by Derk Joester, an engineering and materials science professor at Northwestern University, discovered that small amounts of an “amorphous solid” rich in iron and magnesium are what make rodent teeth resistant to acid. “[We’ve made a] big step forward in understanding the composition and structure of enamel—the tooth’s protective outer layer…,” said Joester.

Researchers included Jill D. Pasteris, a professor of earth and planetary sciences at Washington University in St. Louis. She calls their findings a great example of “the structural-chemical novelty [we’re] still discovering in natural, biomineralized materials” like teeth and bone.

Looking at the teeth of beavers and other rodents, the researchers used powerful technology to map the enamel’s structure, atom by atom. They subjected the teeth to acid and took images before and after. The journal Science published this unprecedented imaging study of tooth enamel in February.

Some of the details of the research are pretty technical, but you really should give a dam about the results. Although a beaver’s teeth are chemically different from our teeth, they’re not structurally different, and the results of the study may lead to stronger tooth enamel and better fluoride treatments.

This news is especially encouraging in light of what we’ve just learned about the sugar industry. The industry has for years covered up proof that reducing sugar-consumption prevents tooth decay. The San Francisco Examiner reports that researchers at UC San Francisco have found documents revealing how the industry worked with the National Institutes of Health (NIH) to avoid condemning sugar, trying instead to develop alternatives (like a vaccine to prevent tooth decay).

Buried in an archive of industry documents discovered at the University of Illinois was a startling document. It showed that a sugar-industry group acknowledged as early as 1950 that sugar causes tooth decay. But, according to the UCSF researchers, Dr. Cristin Kearns and Laura Schmidt, the sugar industry influenced NIH to steer scientists toward developing alternative approaches to tooth decay instead of focusing on the damage done by sugar consumption. (The study is published this month in the scientific journal PLOS Medicine.)

Does this remind you of the tobacco industry and its efforts to suppress scientific evidence that smoking leads to cancer and other illnesses?

The damage caused by sugar is finally getting attention from scientists, and efforts to cut back on its consumption are gaining ground. Last November, voters in Berkeley imposed a tax on sugary drinks, and a majority of San Francisco voters approved a soda tax (it didn’t become law because it required two-thirds to pass). [My blog post, “Gimme a Little Sugar,” published on 10/2/14, focuses on the damage done by sugary drinks and by sugar in general.]

Three SF supervisors have just renewed their efforts to restrict the consumption of sugary drinks in San Francisco. But even if efforts like these succeed, we’ll still face the problem of tooth decay for years to come. So paying attention to beavers’ teeth may prove helpful.

Let’s snatch victory from the jaws of tooth decay. If we start by Leaving it to Beavers, our descendants may someday sport decay-resistant teeth just like theirs.