Nearly one in five bags of potato crisps in Spain contain levels of the carcinogenic substance acrylamide that are higher than what is recommended as healthy by the European Commission, according to the study under the Spanish Institute of Food Science, Technology and Nutrition (ICTAN).
Researchers presented the study at a conference by the European Food Safety Authority (EFSA) in Milan last week.
Acrylamide is defined by the European Food Safety Authority (EFSA) as a "chemical that naturally forms in starchy food products during high-temperature cooking". EFSA states that its presence in food can potentially increase the risk of developing cancer.
Potato products are one of the biggest food groups that expose people to acrylamide, as well as coffee and crisp bread. Cigarettes may also contain the substance.
The researchers analyzed 40 different potato crisp brands between 2004 and 2014. The levels of acrylamide among the crisp bags seemed to differ greatly with variations of up to 80 percent.
The ICTAN study found that Spaniards' overall exposure to the substance has decreased over the past decade, but emphasized that the country must continue efforts to reduce it further.
The study authors warned of the "unreasonably high levels" that can be combated through choosing better produce and improving cooking methods, but also praised the downward trend, reported newspaper El Pais.
Potato crisps in 2014 had 57.6 percent less of the substance than in 2004.
"We believe that with a proper education campaign, we could get the whole sector in a short time to be below the target set by the Commission," said study co-author Francisco Morales.