Cookbooks 'Increase Risk Of Food-Borne Illness' Through Poor Safety Instructions, Warn Scientists

'Cooking time is particularly unreliable.'

If you rely on instructions in recipe books to make your dinner, you could be putting your health at risk.

A new study looked into the instructions in bestselling cookbooks and analysed them in relation to food safety - with some striking results. 

The researchers found a number of books included advice that was “inaccurate and not based on sound science”.

In particular, they found some cooking temperatures listed for meat and eggs were not high enough to reduce the risk of food poisoning. 

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Researchers from North Carolina State University evaluated almost 1,500 recipes from 29 cookbooks that appeared on the New York Times bestsellers list for food and diet books. 

All of the recipes included handling raw animal ingredients, such as meat, poultry, seafood or eggs.

“Cookbooks aren’t widely viewed as a primary source of food-safety information, but cookbook sales are strong and they’re intended to be instructional,” said senior author Ben Chapman.

“Cookbooks tell people how to cook, so we wanted to see if cookbooks were providing any food-safety information related to cooking meat, poultry, seafood or eggs, and whether they were telling people to cook in a way that could affect the risk of contracting food-borne illness.” 

To that end, the researchers specifically looked at three things:

  • Does the recipe tell readers to cook the dish to a specific internal temperature?

  • If it does include a temperature, is that temperature one that has been shown to be “safe”? For example, cooking chicken to 165°F (73°C).

  • Does the recipe perpetuate food-safety myths – such as saying to cook poultry until the juices “run clear” – that have “been proven unreliable as ways of determining if the dish has reached a safe temperature?”

The researchers found that only 123 recipes – 8% of those reviewed – mentioned cooking the dish to a specific temperature. And not all of the temperatures listed were high enough to reduce the risk of food-borne illness.

“In other words, very few recipes provided relevant food-safety information, and 34 of those 123 recipes gave readers information that wasn’t safe,” Chapman said.

“Put another way, only 89 out of 1,497 recipes gave readers reliable information that they could use to reduce their risk of food-borne illness.”

In addition, 99.7% of recipes gave readers “subjective indicators” to determine when a dish was done cooking. And none of those indicators were reliable ways to tell if a dish was cooked to a safe temperature, the researchers said. 

“The most common indicator was cooking time, which appeared in 44% of the recipes,” said lead author Katrina Levine.

“And cooking time is particularly unreliable, because so many factors can affect how long it takes to cook something: the size of the dish being cooked, how cold it was before going into the oven, differences in cooking equipment, and so on.”

Other common indicators used in the cookbooks included references to the colour or texture of the meat, as well as vague language such as “cook until done”.

“This is important because cooking meat, poultry, seafood and eggs to a safe internal temperature kills off pathogens that cause food-borne illness,” Levine said.

“These temperatures were established based on extensive research, targeting the most likely pathogens found in each food.”

Chapman called on cookbooks to help consumers make tasty food, but also to include relevant information to reduce our risk of getting sick.

“A similar study was done 25 years ago and found similar results – so nothing has changed in the past quarter century,” he said.

“But by talking about these new results, we’re hoping to encourage that change.”

Commenting on the study, dietitian and British Dietetic Association spokesperson Marcela Fiuza told The Huffington Post UK: “There are more than 500,000 cases of food poisoning a year in the UK and poultry meat is the food linked to the most cases according to the Food Standards Agency.

“There is not evidence that these are linked to people following recipes from particular cookbooks. Nevertheless, as cookbooks become more and more popular, authors should ensure they are providing cooking advice in line with safety recommendations regarding time/temperature.”

The paper, ‘Evaluating food safety risk messages in popular cookbooks’, is published in the British Food Journal.