So much for rest in peace.
How do you do justice to the truth in a headline-driven world?
- The internet is parasitic on traditional media sources, says Keith Whittington. Traditional news outlets do the hard reporting to generate the facts and notable opinions that other outlets respond to.
- The greatest challenge to truth in journalism is that social media presents news stories out of context; we no longer see news among other news articles, and we may only ever see the headline without the detail and nuance required.
- Media institutions are working to tackle these challenges, but until then it is our responsibility as citizens and consumers to get smarter about how we navigate news feeds and the hyper-partisan press.
Unhealthy diets cause the part of your brain responsible for appetite to become inflamed, encouraging further eating and obesity.
- Anyone who has tried to change their diet can tell you it's not as simple as simply waking up and deciding to eat differently.
- New research sheds light on a possible explanation for this; high-fat diets can cause inflammation in the hypothalamus, which regulates hunger.
- Mice fed high-fat diets tended to eat more and become obese due to this inflammation.
Your wardrobe won't be the only thing a bad diet will change in your life — new research published in Cell Metabolism shows that high-fat and high-carbohydrate diets physically change your brain and, correspondingly, your behavior. Anyone who has tried to change their diet can tell you that it's far more challenging than simply deciding to change. It could be because of the impact high-fat diets have on the hypothalamus.
Yale researcher Sabrina Diano and colleagues fed mice a high-fat, high-carb diet and found that the animals' hypothalamuses quickly became inflamed. This small portion of the brain release hormones that regulate many autonomic processes, including hunger. It appears that high-fat, high-carb diets create a vicious cycle, as this inflammation caused the mice to eat more and gain more weight.
"There are specific brain mechanisms that get activated when we expose ourselves to specific type of foods," said Diano in a Yale press release. "This is a mechanism that may be important from an evolutionary point of view. However, when food rich in fat and carbs is constantly available it is detrimental."
A burger and a side of fries for mice
The main driver of this inflammation appeared to be how high-fat diets changed the mice's microglial cells. Along with other glial cells, microglia are a kind of cell found in the central nervous system (CNS), although they aren't neurons. Instead, they play a supporting role in the brain, providing structure, supplying nutrients, insulating neurons, and destroying pathogens. Microglia work as part of the CNS's immune system, seeking out and destroying foreign bodies as well as plaques and damaged neurons or synapses.
In just three days after being fed a high-fat diet, the mice's microglia activated, causing inflammation in the hypothalamus. As a result, the mice started to eat more and became obese. "We were intrigued by the fact that these are very fast changes that occur even before the body weight changes, and we wanted to understand the underlying cellular mechanism," said Diano.
In mice fed with a high-fat diet, the researchers found that the mitochondria of the microglia had shrunk. They suspected that a specific protein called Uncoupling Protein 2 (UCP2) was the likely culprit for this change, since it helps to regulate the amount of energy microglia use and tends to be highly expressed on activated microglia.
To test whether UCP2 was behind the hypothalamus inflammation, the researchers deleted the gene responsible for producing that protein in a group of mice. Then, they fed those mice the same high-fat diet. This time, however, the mice's microglia did not activate. As a result, they ate significantly less food and did not become obese.
An out-of-date adaptation
When human beings did not have reliable access to food, this kind of behavioral change would have been beneficial. If an ancient human stumbled across a high-fat, calorically dense meal, it would make sense for that individual to eat as much as they could, not knowing where it's next meal would come from.
But there were no Burger Kings during the Pleistocene. Humanity has been extraordinarily successful in changing its environment, but our genome has yet to catch up. The wide availability of food, and especially high-fat foods, means that this adaptation is no longer a benefit for us.
If anything, research such as this underscores how difficult it is to really change bad habits. A poor diet isn't a moral failing — it's a behavioral demand. Fortunately, the same big brains that gave us this abundance of food can also exert control over our behavior, even if those brains seem to be working against us.
Should all speech be free? How much intolerance should society tolerate?
- For society to stay open and free, you don't need to eliminate prejudice. You need the opposite: All kinds of prejudice pitted against each other.
- Intellectual diversity helps society as a whole learn the truth. And as long as society has rules that force ideas to be openly tested, the intolerant will not gain the upper hand.
- "In America it's legal to be intolerant. It may not be right. It may not get you accepted or respected. But absolutely it's legal and it should be legal," says Jonathan Rauch.
The system could help with diagnosing and treating patients that cannot communicate.
A question that's baffled physicists for 9 years is resolved the simplest possible answer.
- A startling result nine years ago sent physicists scrambling.
- Protons and muons and hydrogen might have been caught doing something unexpected.
- Incredibly accurate new research definitively solves the riddle.
Take the circumstances in your life seriously, but not literally. Here's why.
- Galileo was quite controversial, in part, because he argued that Earth moved around the sun, despite people's senses deluding them that the world was static.
- Evolution may have primed us to see the world in terms of payoffs rather than absolute reality — this has actually helped us survive. Those who win payoffs are more likely to pass on their genes, which encode these strategies to get to the "next level" of life.
- It's important to listen to people's objections because they may bring something to your attention outside your ken. Learn from them to make your ideas sharper.
An amateur astronomer discovers an interstellar comet on its way to our Sun.