By Stephanie Stahl

By Stephanie Stahl

PHILADELPHIA (CBS) — Researchers say 10 percent of all food is either mislabeled or misrepresented.  3 On Your Side Health Reporter Stephanie Stahl shows us the most common items that may not be what they seem.

Navigating the grocery store can be a challenge, so many ingredients to decipher.  But careful label reading might not be enough.

“It’s very frustrating that they don’t tell the public what is in their products.  It’s very frustrating,” said Jackie Wohlgemuth, a consumer.

“It’s not food as labeled,” said Amy Kirchner, who runs the National Center for Food Protection and Defense.  It’s created under the Department of Homeland Security to prevent food terrorism, and ensure the labels are accurate.

“We’ve lost control of a supply chain, so it allows people to take advantages of vulnerabilities in the system,” said Kirchner.

The Center has found dozens of examples of fraud, everything from fillers in spices to diluted lemon juice to more serious and potentially dangerous problems, as with olive oil.

“If it’s adulterated with oils that we don’t consume, so industrial oils or oils you wouldn’t use for human consumption, and we have had cases historically where people have adulterated and made people very ill,” said Kirchner.  Alcohol can also have some undisclosed ingredients, like a chemical called Diethylene glycol.

“It’s like an antifreeze that was added to wine to sort of increase the movement in your mouth,” said Kirchner.

Honey is another item that was often found to be fraudulent, containing ingredients not on the label like corn syrup or it can come from other countries that use antibiotics.

“To increase production of honey through their bee population and that might be a substance that we ban,” said Kirchner.

With seafood, instead of unlabeled ingredients, the Center says sometimes a cheaper type is sold as a more expensive kind of fish.

“Substituting escolar for tuna,” said Kirchner.  That can be dangerous because some fish can cause gastrointestinal problems or contain high levels of toxins.

Experts say it’s very hard to spot fraud.  One of the simple rules, if one brand of a product is much cheaper than all the others, that could be a sign that it has fake ingredients.