Health briefs: Iced tea and kidney stones

Kidney stone risk

People who drink iced tea may be putting themselves at greater risk for developing painful kidney stones, a new study indicates. Researchers from Loyola University Medical Center explained that the popular summertime drink contains high levels of oxalate, a chemical that leads to the formation of small crystals made of minerals and salt found in urine. Although they usually are harmless, the researchers cautioned they can grow large enough to become lodged in the small tubes that drain urine from the kidney to the bladder.

Long-term fun

When it comes to human courtship, a little silliness and kidding around might help ensure success, scientists say. Unlike other mammals, that tend to get down to business as they seek a mate, humans keep their sense of "playfulness" with each other well into adulthood, according to researchers at Pennsylvania State University. That injection of fun into the courtship ritual may be rooted in human evolution, they noted, and people who possess more playfulness may be demonstrating positive qualities to potential long-term mates.

-- HealthDay