Today’s Headlines: Junk Food, Fluoride and Snacking

Switching to junk food leads to a major change in gut bacteria. More and more research is showing that what you eat directly affects the bacteria in your gut and a new study out this week has found that adding junk food can have a major impact on the health of your gut flora. “Researchers asked people to switch diets for two weeks. 20 US volunteers moved to a low-fat, high-fiber diet while 20 volunteers from rural Africa were asked to eat more ‘junk’ food. The Western-style diet given to the native African volunteers was typical junk or fast food like burgers and fries. The US volunteers were switched to a diet containing lots of pulses and beans. Although the swap was brief, its impact was visible. The dietary swaps appeared to cause significant changes to the cells lining the gut as well as the bacteria that live in the bowel – with the US volunteers faring better. The Americans benefited from less bowel inflammation, while the African volunteers’ bowel health deteriorated. It is not possible to make any firm conclusions based on such a small study, say experts. But the findings do support the belief that modern Western diets, which are high in fat and sugar and low in fiber, are bad for us.” (BBC)

U.S. government seeks to lower fluoride levels in drinking water. The U.S. government started adding fluoride to protect against cavities more than 50 years ago. But with the widespread adoption of fluoridated toothpastes and mouthwashes, it’s looking to lower that level. “Federal health officials Monday changed the recommended amount of fluoride in drinking water for the first time since 1962, cutting by almost half the maximum amount of fluoride that should be added to drinking supplies. The Department of Health and Human Services recommended 0.7 milligrams of fluoride per liter of water instead of the long-standing range of 0.7 to 1.2 milligrams. The change is recommended because now Americans have access to more sources of fluoride, such as toothpaste and mouth rinses, than they did when fluoridation was first introduced in the United States. As a result, many Americans are getting too much fluoride, which is causing a big increase in a condition known as fluorosis that causes very faint white marks on people’s teeth.” While some opponents of fluoridated water have argued that fluoride may lead to negative health effects, proponents point out that no strong studies have shown widespread, negative health effects and that fluoridated water dramatically decreases tooth decay. (NPR)

Neurons behind the unpleasantness of hunger discovered. The feeling of hunger is an unpleasant one that can make you irritable and stressed. While researchers had long observed this emotional component to hunger, they’ve only just discovered which part of the brain makes going without food so unpleasant. “The team found evidence it’s the desire to get rid of the unpleasant feelings associated with hunger that drives eating. A group of nerve cells called agouti-related peptide neurons (AgRP) are critical for regulating when animals eat. When calories dwindle and energy drops, AgRP are active, fueling appetite. These neurons are kicking in when we start to lose 5%, or 10% of body weight and they are a big part of why most diets fail even though people do succeed in initially losing weight.” The researchers did their study in mice and played with the activity of these neurons to get a sense of how they worked. They realized that mice did eat to turn off the activity of these neurons, rather than for the pleasure of eating. “It’s the same with people, which explains why diets are hard to keep up. But the team thinks it may be possible to manipulate the MC4 cells and fool the body into feeling the same satisfaction that comes with a full belly.” (TIME)