For a quick break from the more serious health news of the day, I reviewed details of a somewhat amusing study by researchers at National University in La Jolla, Calif., that found police departments could go a long way toward more quickly identifying crime suspects if they conducted DNA samples of partially eaten food.
This new research built on the results of a 32-year-old study featured in the British Dental Journal that found "Criminals appear to be unable to resist food, chocolate or fruit that they find on premises into which they enter illegally. They are also inclined to leave, at the site, the unconsumed portions." For years, forensic scientists have studied traces of food for bite-marks and DNA identification is quite common. This new study tested the reliability of recovering DNA from partially eaten food and what kinds of foods should be examined first.
For the test, scientists hosted a dinner party for 13 people, featuring a variety of processed and non-processed foods. Guests were instructed to eat a few bites of the food and leave the rest behind. Complete DNA samples were found on 43 percent of the swabs tested and partial samples were found on 33 percent.
The foods that contained the most DNA: pizza, cheese, carrots and apples. On the other hand, bite-size chocolate showed the least amount of DNA due to their small size, scientists said.
If the guests ate the chocolate and it did not harbor any saliva for an analysis, this is probably related to its high polyphenolic bioflavanoid content. More confirmation chocolate may in fact be a health food.
New Scientist March 10, 2005