Early Exposure to Germs Shows Lasting Benefits - More evidence that the first world is too clean for its own good:
In a study published online March 23 in Science, the researchers show that in mice, exposure to microbes in early life can reduce the body's inventory of invariant natural killer T (iNKT) cells, which help to fight infection but can also turn on the body, causing a range of disorders such as asthma or inflammatory bowel disease. The study supports the "hygiene hypothesis," which contends that such auto-immune diseases are more common in the developed world where the prevalence of antibiotics and antibacterials reduce children's exposure to microbes.... The study also found that a lack of exposure in early life could not be compensated for by introducing the [germ-free] mice to a broader range of microbes in adulthood.Seduced by Food: Obesity and the Human Brain - A good overview by Stephan J. Guyenet of why cheese and beer are delicious and everyone is suddenly fat:
First described in 1976 by Anthony Sclafani, the cafeteria diet is basically a rat-sized buffet of human junk food, in addition to regular rat chow. The menu for a recent cafeteria diet study included such delectable items as Froot Loops, mini hot dogs, peanut butter cookies, Cheez-its, Cocoa Puffs, nacho cheese Doritos, cake, and BBQ pork rinds. These are what's known in the business as ‘palatable’, or pleasurable to the taste. On this regimen, rats ignored their regular chow, ate junk food to excess and gained fat at an extraordinary rate, far outpacing two comparison groups fed high-fat or high-sugar pelleted diets. Yes, human junk food happens to be the most effective way to overwhelm the body fat homeostasis system in rats, and neither fat nor sugar alone is able to fully explain why it’s so fattening. Importantly, over time, rats become highly motivated to obtain this diet—so motivated they’ll voluntarily endure extreme cold temperatures and electric shocks to obtain it, even when regular bland rodent pellets are freely available.
The cafeteria diet is an exaggerated version of an unhealthy human diet, and not many people eat quite that poorly. However, have a look at the top six calorie sources in the current US diet, in order of calorie contribution: grain-based desserts (cake, cookies, etc.), yeast breads, chicken-based dishes, sweetened beverages, pizza and alcoholic beverages. Our eating habits aren’t as different from the cafeteria diet as we might like to believe.