Alicia Silverstone both puzzled and seriously grossed many of us out with the news that she "premasticates" her son Bear Blu's food.
In a video posted on her site, the actress and notorious vegan-ess explained that she feeds her 10-month-old small bits of pre-chewed food -- "from my mouth to his."
So what gives?
Saliva, as Science Daily points out, is 98 percent water, but plays a crucial role in making food moist and easily swallowable.
And it turns out, Silverstone isn't alone in her pre-chewing habits.
According to a letter in the journal Clinical Infectious Diseases, premastication of solid foods by nursing mothers is "commonplace among diverse cultures around the world" -- particularly in resource-strapped areas where clean water and baby formula are not always available.
And a study published in the journal Maternal & Child Nutrition suggests that, until recent times, pre-chewing played a "crucial role" in supporting infant health. That same paper posits that its abandonment, particularly in poor communities, "has placed children at increased risk of inadequate nutrition and decreased ability to confront infections associated with the introduction of complementary foods."
Here in the U.S.?
Well, premastication may be more popular than people think: According to a Centers for Disease Control report, approximately 14 percent of the caregivers here report engaging in the behavior.
But while pre-chewing may have some benefits by helping infants get nutrients they need, the possible health risks of premastication are also well-documented.
That same CDC report states that premastication has been identified as a possible route of HIV transmission through blood in saliva, as well as other pathogens. It cites studies looking at the possible transmission of hepatitis B and herpes.
A study in Pediatrics detailed three cases of HIV transmission in the U.S. possibly linked to premastication.
And the Orlando Sentinel reported on an Iowa-based insurance company, Delta Dental, that said in a press release that pre-chewing can pass along dental disease.
The bottom line? Pre-mastication may have some documented health benefits, but opponents say it's not without health risks, so it's probably best to speak with your health care provider before you have an urge to chew ... and spew.