Fruits and vegetables that are rich in nitrates protect the stomach from damage.
According to ScienceDaily, this takes place through conversion of nitrates into nitrites by the bacteria in the oral cavity and subsequent transformation into biologically active nitric oxide in the stomach.
The Swedish researcher Joel Petersson has described the process, which also means that antibacterial mouthwashes can be harmful for the stomach.

Nitrate-rich vegetables such as spinach, lettuce, radishes and beetroot have a positive effect on the stomach by activating the mucous membranesÕ own protective mechanisms.

“Nitrates in food have long been erroneously linked to an increased risk of cancer,“ says Joel Petersson of Uppsala University’s Department of Medical Cell Biology.
He instead thinks that nitrate-rich vegetables such as spinach, lettuce, radishes and beetroot have a positive effect on the stomach by activating the mucous membranes’ own protective mechanisms, thus reducing the risk of problems such as gastric ulcers.
In the body the blood circulation transports nitrates to the salivary glands, where they are concentrated. When we have eaten nitrate-rich food our saliva thus contains large amounts of nitrates, which the bacteria of the oral cavity partially convert into nitrites. When we swallow the nitrites they come into contact with acid gastric juice, and are then converted into the biologically active substance nitric oxide. This results in our developing high levels of nitric oxide in the stomach after eating vegetables.
It has long been known that nitric oxide is produced by various enzymes in the human body, but the fact that nitric oxide can also be formed in the stomach from nitrites in the saliva, entirely without the involvement of enzymes, is a relatively new discovery.
Researchers still have very little idea of how the stomach is affected by these high levels of nitric oxide. Joel Petersson’s thesis shows that the nitric oxide that is formed in the stomach stimulates the protective mechanisms of the mucous membrane--because the stomach constantly has to protect itself so as not to be broken down together with the food ingested.
Two such important defence mechanisms are the stomach’s constant renewal of the mucous layer that covers the mucous membrane and its maintenance of a stable blood flow in the mucous membrane.
The nitric oxide widens the blood vessels in the mucous membrane, thus increasing the blood flow and regulating elimination of the important mucus. Together, these factors lead to a more resistant mucous membrane.
Using animal models Joel Petersson and his colleagues have shown that nitrate additives in food protect against both gastric ulcers and the minor damage that often occurs in the gastrointestinal tract as a result of ingestion of anti-inflammatory drugs.
“These sorts of drugs are very common in the event of pain and inflammation. They have the major disadvantage of causing a large number of serious side-effects in the form of bleeding and ulcers in the gastrointestinal tract. With the aid of a nitrate-rich diet you can thus avoid such damage,“ he explains.

Billions of years ago, a weaker sun should have made the Earth a chilly place--so why was it balmy instead?
The sun that shone on the early Earth was around 25 percent dimmer than today, so atmospheric temperatures should have been colder by around 25 ¡C. But ancient rocks show that liquid water existed, proving that temperatures must have been above freezing, NewScientist said.
This can be explained if greenhouse gases acted as an insulator--but modeling has showed that carbon dioxide in the atmosphere would need to have had an implausibly high partial pressure of over 50 millibars to trap the heat.
Now Philip von Paris of the German Aerospace Center in Berlin and colleagues have built a model that they say better simulates the types, pressures and layering of atmospheric gases at that time.
This showed that the atmosphere itself was a better insulator than we thought, and CO2 with a partial pressure of only 2.9 millibars would have kept temperatures above freezing between 2 and 2.5 billion years ago. The work will appear in Planetary and Space Science.
Unfortunately, this still doesn’t resolve the paradox between 2.5 and 4.6 billion years ago, when the sun was even weaker, and not everyone is convinced the researchers are right.

Positioning child safety seats in the center of the back seat could cut infants’ and toddlers’ injury risks by nearly half, a new study suggests.
In a study of car crash data from 16 US states, researchers found that children younger than 3 years old were 43 percent less likely to be injured when their seat was fastened in the center of the back seat rather than one of the side seats, Reuters said.
Experts already recommend that parents position car seats in the center of the rear seat, and the current findings bolster that advice, according to Michael J. Kallan and colleagues at the University of Pennsylvania and Children’s Hospital of Philadelphia.
Unfortunately, only 28 percent of children in their study were sitting in that position at the time of the car accident, the researchers report in the journal Pediatrics.
There are obstacles to placing a car seat in the center position, Kallan’s team acknowledges.
It is physically harder to strap a child, especially a heavier child, into a center-positioned seat. A centered child seat can also make it difficult for other people to sit in the rear of the car. But based on the current findings, the researchers write, this center position is the safest place for babies and toddlers to ride.