June 22, 2017 -- Few of us are under the illusion that french fries – or any fried foods -- are good for us. But could eating them actually shorten our life?
Although the connection between eating fried foods and obesity and heart disease is well known, a study published earlier this month is the first to link eating fried potatoes to death risk.
The study found people who ate fried potatoes (including french fries, fried potatoes, and hash browns) more than twice a week were more likely to die early than those who ate fried potatoes less often.
The report included 4,440 people, ages 45 to 79, who were enrolled in a study that looked at ways to prevent and treat knee osteoarthritis. Researchers followed participants over an 8-year period and asked them about their diet -- including the amount of fried and unfried potatoes they ate.
Study author Nicola Veronese, MD, said they focused on potatoes because the link between eating them and death risk hadn’t been studied before. Some studies had found that potatoes raise the odds of having heart disease and other medical conditions, says Veronese, a researcher at the Institute of Clinical Research and Education in Medicine in Padova, Italy.
After 8 years, the chance of early death was about twice as high in the group that ate fried potatoes more than 2 times a week. What about french fries might have contributed to the participants' premature demise?
“We think that several mechanisms could lead to mortality,” Veronese says. First, he says, people who eat more potatoes have a higher incidence of medical conditions that can increase the risk of death. Also, "The potatoes are fried in unhealthy oils rich in trans fats. Finally, the high amounts of salt used further increase the risk of death.”
Are French Fries Really Deadly?
Before you swear off french fries forever, here are a few things to consider. First, the study didn't determine exactly how the study participants died. “Those deaths might have had nothing to do with diet. They could have been run over by a car,” says Ken Lee, PhD, a professor in the department of food science & technology at the Ohio State University Food Innovation Center.
Second, it relied on the participants' memory of what they ate. “That is one of the least reliable forms of diet studies,” Lee says.
The researchers also didn't prove that french fries caused an early death. “We don't know what other things in their diet and lifestyle may have contributed to their death,” says Lisa Sasson, a clinical assistant professor of nutrition in the NYU Department of Nutrition and Food Studies.
She adds that unless a food is poisonous or tainted with bacteria, it's not likely to kill you on its own. “That's a very simplistic way of looking at it.”
Fried Food Risks
That doesn't mean you should go on a french fry binge -- or binge on any fried foods. Fried foods are high in fat, calories, and often salt. A few studies, including one published in 2014, have linked fried foods to serious health problems like type 2 diabetes and heart disease.
"Fried foods may influence risk of these diseases through several key risk factors: obesity, high blood pressure, and high cholesterol," says lead author Leah Cahill, PhD, an assistant professor at Dalhousie University in Canada. “The process of frying is known to alter the quality and increase the caloric content of food.”
Fried foods served in fast-food restaurants are often cooked in hydrogenated oils, which are high in trans fats. Many restaurants use these oils because they give food a satisfying taste and crunch. But they're not good for you. Trans fats raise bad (LDL) cholesterol levels, lower good (HDL) cholesterol levels, and raise your chance of having heart disease.
Hydrogenated oil is especially unhealthy when it's reused, which restaurants often do. Oils break down with each frying, which changes their composition and causes more oil to be absorbed into the food, Cahill says. These changes further boost your chances of having high cholesterol and high blood pressure.
The FDA ban on trans fats, which takes full effect in 2018, won’t necessarily make fried foods healthier, Cahill says. Many restaurants have already switched to other oils in advance of the ban.
“The trans fat ban will make fried foods safer theoretically, but restaurants will still be able to use unhealthy oils, including oils that have been reused a lot. It will be important to monitor the long-term health effects of the new oils being used.”
Add Sasson: “Eating fried foods (deep fried) is not a healthy choice. Fried foods add a lot of calories to food and don't offer healthy nutrients.”
The Acrylamide Connection
Another worry with fried food centers on acrylamide, a chemical that forms in foods cooked at high temperatures, such as fried and baked foods. Acrylamide has been shown in animal studies to cause cancer.
When food is cooked at very high heat, an amino acid -- asparagine -- in the food reacts with sugars to produce acrylamide. This chemical can form in many fried foods, but it's especially common in potatoes, which are high in sugars like fructose and glucose.
How much you fry the food also matters. "The darker the food, the more acrylamide there is," says Lee, who was on the FDA's Food Advisory Committee evaluating acrylamide safety. "A dark potato chip, dark french fry, or darker fried chicken would have more."
If you're healthy, eating moderate amounts of acrylamide-containing fried foods is probably not dangerous, he says. But if you have a family history of cancer, "You need to be conscious of how many fried foods you eat."
Safer Frying and Frying Alternatives
If you're going to eat fried foods, make them yourself at home, where you can control the type of oil you use. "Liquid oils are the healthiest options, because they contain high amounts of the 'healthy fats' -- polyunsaturated and monounsaturated fats," Cahill says. Olive, soybean, and canola oils are all good choices. These oils are also high in heart-healthy omega-3 fatty acids.
Never reuse oil when you fry. Start with a fresh batch each time. And when you're done frying, use paper towels to soak any excess oil off the food.
To cut down on acrylamide levels, don't let your foods get too brown. Another trick is to store your potatoes at room temperature, not in the fridge. "When potatoes sit in the refrigerator, it creates more sugar, and the sugar makes more acrylamide," Lee says.
A few easy food hacks will let you enjoy the taste and texture of fried food, without the frying. Spritz sliced white or sweet potatoes with an olive oil spray and roast them in the oven, Sasson suggests. Dip chicken cutlets in egg whites, roll them in breadcrumbs, and spray them with olive oil to mimic fried chicken. "It's going to be crisp and crunchy, and you use very little oil," she says.
You don't have to give up fried food, but you also don't want to overdo it. "Have fried potatoes once in a while as more of a treat than a daily part of your diet," Sasson says. Order them with a salad rather than a burger, to boost the nutrition in your meal.
"Moderation and variety with any food is the key to healthy eating and a healthy lifestyle," Lee adds. "It's habitual consumption that could get you into trouble."