Food/Sex/Music: All the Same to the Brain

Whether it's the Beatles or Beethoven, people like music for the same reason they like eating or having sex: It makes the brain release a chemical that gives pleasure, a new study says.

Previous work had already suggested a role for dopamine, a substance brain cells release to communicate with each other. But the new work, which scanned people's brains as they listened to music, shows it happening directly.

While dopamine normally helps us feel the pleasure of eating or having sex, it also helps produce euphoria from illegal drugs. It's active in particular circuits of the brain.

The tie to dopamine helps explain why music is so widely popular across cultures, Robert Zatorre and Valorie Salimpoor of McGill University in Montreal write in an article posted online Sunday by the journal Nature Neuroscience.

The study used only instrumental music, showing that voices aren't necessary to produce the dopamine response, Salimpoor said. It will take further work to study how voices might contribute to the pleasure effect, she said. Music isn't the only cultural experience that affects the brain's reward circuitry. Other researchers recently showed a link when people studied artwork.

Nature Neuroscience

What's in Your Drinking Water?

Hexavalent Chromium Found in Drinking Water of 31 US Cities

(Erin Brockovich made Hexavalent Chromium popular back in 2000-you remember the movie)

An environmental group that analyzed the drinking water in 35 cities across the United States, including Bethesda and Washington, found that most contained hexavalent chromium, a probable carcinogen.

The federal government restricts the amount of "total chromium" in drinking water and requires water utilities to test for it, but that includes both trivalent chromium, a mineral that humans need to metabolize glucose, and hexavalent chromium, the metal that has caused cancer in laboratory animals.

Last year, California took the first step in limiting the amount of hexavalent chromium in drinking water by proposing a "public health goal" for safe levels of 0.06 parts per billion. If California does set a limit, it would be the first in the nation.

Hexavalent chromium was a commonly used industrial chemical until the early 1990s. It is still used in some industries, such as in chrome plating and the manufacturing of plastics and dyes. The chemical can also leach into groundwater from natural ores.

More Info Found at Environmental Working Group

Do Barefoot Running Shoes Really Work?

By: Dr. Robert A. Kornfeld

Barefoot running shoes are designed to re-create a "natural," barefoot running dynamic on "unnatural" surfaces like concrete, asphalt, red top, black top, etc. How can we have a barefoot running shoe? Doesn't barefoot denote without shoes?

Choosing to run on non-yielding surfaces without the protection afforded by proper running shoes can be harmful to the foot and ankle and cause even more problems downstream from compensation patterns. So what really are these pedal marvels and why is everyone running to take their shoes off?

Barefoot running shoe manufacturers believe that the human foot, unimpeded by synthetic surfaces and restrictive running shoes, should function at its best. That is a correct assumption, save for the fact that the human foot was designed long before the paving of roads. In fact, uneven, grassy surfaces are the most natural surface for the human foot because it helps the body navigate and respond to uneven terrain, while at the same time absorbs shock, stabilizes weight and propels the body forward. In order for this to occur successfully, most of us are born with a flexible forefoot and a rigid or stable rearfoot. In other words, at heel strike -- when your heel hits the ground -- your leg from the hip down is aligned for optimal function and is stabilized during normal walking.

So who should be using barefoot running shoes? The answer is very few people should. Only those people with stable (not flexible) first metatarsals will do well with these shoes, as well as those with very powerful lower leg musculature (although even those with powerful lower leg function will ultimately go on to some type of pathology).

For the full article click here

Americans Falsely Believe Their Diet is Healthy

Nine in 10 Americans say their diet is healthy but only a quarter limit the amount of fat or sugar they eat, and two-thirds don't eat enough fruit and vegetables. "Americans tend to give themselves high marks for healthy eating, but when we asked how many sugary drinks, fatty foods, and fruits and veggies they consumed, we found that their definition of healthy eating was questionable," said Nancy Metcalf of Consumer Reports Health, which conducted a recent poll.

Of the 1,234 American adults polled, 89.7 percent said their diet was "somewhat" (52.6 percent), "very" (31.5 percent), or "extremely" healthy (5.6 percent). But 43 percent of the survey respondents said they drank at least one sugary soda or other sweetened drink every day, and just one in four said they limited sweets, sugars or fats in their diet, the poll conducted in early November found. Four in 10 Americans said they ate "pretty much everything" or "mostly everything" that they wanted. A third said they were at a healthy weight when they actually had a body mass index (BMI) of an overweight or obese person, while eight percent thought they were overweight or obese, but their BMIs suggested they were not. One in three adults is obese.

www.discovery.com