Nutritional Pearls: A Further Look at the Risks of Fried Foods

Answer: It Is Best to Avoid Fried Foods

People will sometimes tell me that it is not worth listening to nutrition advice because "it changes all the time." 

A case in point: Early in 2019, I reported on a study¹ that showed that women who consumed fried chicken at least once per week saw a 13% greater risk of death from all causes than those who consumed the least amount of fried food in general. 

Then in September 2020, I shared a study² of folks in Spain: Those who ate the most fried foods were 9% less likely to have a stroke than those who ate the least fried foods. 

I can understand patients’ frustration: Are fried foods bad for you or not?  

The problem? The definition of "fried." 

The Research

The study from Spain, for example, recorded where the fried foods came from, as well as how the fried foods were cooked. The majority of fried foods the participants from Spain consumed were made at home, using olive oil for frying—the fried foods people ate were not made in restaurants. In the United States, the vast majority of fried foods consumed are made in commercial deep fryers using corn oil, canola oil, soybean oil, or even animal fat.  

Today's research also must come with some caveats.

A team of researchers in China performed a meta-analysis of 17 published studies of the effects of fried foods on all-cause mortality, major cardiovascular events—including heart disease, stroke, and heart failure—and cardiovascular mortality.³ 

The 17 studies included as few as 200 adults and as many as 566,407 men and women and lasted for as few as 3 and as many as 17.9 years. Each study surveyed the participants regarding their intake of fried foods and compared the outcomes of those who consumed the most fried foods with those who consumed the least.

The Results 

For each outcome, the authors combined the data from the studies that reported on that outcome, finding that for the 11 studies that examined the association between fried food consumption and coronary heart disease (CHD), participants who consumed the most fried foods were 22% more likely to develop CHD than those who consumed the least—an amount that, because of publication bias, was considered clinically nonsignificant. 

Only 4 studies investigated the association between fried foods and heart failure and another 4 for fried foods and stroke, ultimately showing a 37% increased risk of heart failure for participants consuming the most fried foods compared with the least, and the same for stroke. 

Cardiovascular mortality, on the other hand, increased overall by only 3% when comparing the highest consumption of fried foods with the lowest.

What’s the Take Home?

I would have liked to see this research go into more detail regarding the definition of "fried"—that is, was the food “pan fried” or “deep fried”? It also does not specify what foods were fried or in what type of oil.  

This information is unlikely to be found in a meta-analysis like this one, however. A meta-analysis is designed to take a larger-scale view of current research. While there might be instances where frying foods is not quite as bad for you as it could be, the majority of the evidence still indicates that you are best to avoid fried foods except for (very) occasional treats. 

References:

1. Harlan TS. Fried foods: just how bad are they? DrGourmet.com. Published online January 30, 2018. Accessed July 1, 2021. https://www.drgourmet.com/bites/2019/013019.shtml
2. Harlan TS. Eating fried foods doesn’t increase your risk of stroke––but there’s a catch. DrGourmet.com. Published online September 23, 2020. Accessed July 1, 2021. https://www.drgourmet.com/bites/2020/092320.shtml
3. Qin P, Zhang M, Han M, et al. Fried-food consumption and risk of cardiovascular disease and all-cause mortality: a meta-analysis of observational studies. Heart. Published online January 19, 2021. https://doi.org/10.1136/heartjnl-2020-317883

Dr. Gourmet is the definitive health and nutrition web resource for both physicians and patients with evidence-based resources including special diets for coumadin users, patients with GERD/acid reflux, celiac disease, type 2 diabetes, low sodium diets (1500 mg/d), and lactose intolerance.

Timothy S. Harlan, MD, is a board-certified internist and professional chef who translates the Mediterranean diet for the American kitchen with familiar, healthy recipes. He is an assistant dean for clinical services, executive director of The Goldring Center for Culinary Medicine, and associate professor of medicine at Tulane University in New Orleans.