ASK DR. BAUGHAN                                      December 15, 2000

THE COOKIE DOUGH CONUNDRUM

Some of the simplest questions are the hardest to answer, such as the person who wrote in to ask, “Is it safe for my children to eat raw cookie dough?” 

The easy, conservative answer is, “No.  It is known that eggs can be contaminated with the salmonella bacteria that causes food poisoning (vomiting and diarrhea), so never, never  let your children eat cookie dough.”  One of my goals, though, is putting medical risks in realistic perspective.  So I decided to search the Internet since the medical literature seems to be woefully deficient in cookie dough research.  I hoped to find out whether there were any reported cases of food poisoning attributed to cookie dough, or whether anyone had ever studied whether the other ingredients in cookie dough retarded the growth or killed the bacteria or simply diluted the amount of bacteria enough to make the risk negligible.  Since most families with children likely to want to eat cookie cough are doing fifteen things at once around the holidays, it may well occur that little fingers might sneak into the cookie bowl with or without parental permission, and if this happens, how much of a medical crisis is it?

I posed these questions to the Centers for Disease Control, the US Food and Drug Administration, Nabisco.com, Willamette Egg Farms, and Rob Edwards, PhD, a microbiologist at the University of Tennessee, Memphis who helps co-sponsor Salmonella.com, a clearinghouse for information about salmonella research.

The common theme from all the respondents was, “Yes, it is possible to contract salmonella from eating cookie dough, but no one knows the precise risk.”  Several facts emerged that led to recommendations for minimizing the risk.  In some areas, about 50% of flocks (or factories) of chickens might harbor salmonella.  Not all the insides of eggs will be contaminated, though, because the membrane and shell offer pretty good protection.  If there is salmonella on the outside of the shell, and if the egg sits around at room temperature for a while, small cracks may develop in the shell and membrane, allowing the salmonella in.  It may survive in the white of the egg, but cannot multiply much because the white lacks certain nutrients it needs.  If it is then mixed with other ingredients, such as mayonnaise for potato salad, and left in a warm place, it can begin to multiply.  Cooking at 140 degrees for 5 minutes will kill the bacteria.  So the reason soft-boiled eggs or runny-yolk fried eggs are discouraged is not that the runny yolk is bad, but the whites must not have been cooked for five minutes if the yolk is still runny.

To minimize the risk to cookie dough thiefs, keep the eggs refrigerated and use them fresh.  Rinse them before breaking the shells.  Be ready to cook them promptly after preparing the cookie dough.  If something comes up and the cookies cannot be baked right away, put the dough in the refrigerator.  Don’t leave the dough on a kitchen counter.  Wash your hands well before mixing the dough.  If you are using a store-bought cookie dough, check the label to determine if the eggs in the mix are pasteurized.  If so, there is less risk of contamination.

So, “Yes, Virginia, there is a Santa Salmonella.”  But he need not visit every home.  Simple precautions can keep him at  bay.  If sneaky hands get into the dough, watch the child for an upset stomach or diarrhea.  There would be no test or action to take once the child ate some cookie dough unless the child starting acting sick.  Bake the cookies at least 5 minutes, then enjoy!  And if anyone wants to study this further, this could probably make a very good science fair project.