THE CLAIM

Mayonnaise can increase the risk of food poisoning.

THE FACTS

This is the time of year when food poisoning typically spikes, and one popular picnic ingredient that always attracts suspicion is mayonnaise.

But studies cast doubt on that.

Most commercial brands of mayonnaise contain vinegar and other ingredients that make them acidic — and therefore very likely to protect against spoilage. When problems occur, they usually result from other contaminated or low-acid ingredients (such as chicken and seafood), improper storage and handling, or homemade versions.

One prominent study published in The Journal of Food Protection found, for example, that in the presence of commercial mayonnaise, the growth of salmonella and staphylococcus bacteria in contaminated chicken and ham salad either slowed or stopped altogether. As the amount of mayonnaise increased, the rate of growth decreased.

THE BOTTOM LINE

Despite its reputation, mayonnaise can reduce food spoilage.