A further look at the risks of fried food

People will sometimes complain that it's not worth listening to nutrition advice because "it changes all the time."

A case in point: early in 2019 we reported on a study that showed that those 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 foods in general.

Then in September of 2020 we shared a study 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 their frustration: is fried food bad for you, or not?

The problem? The definition of "fried."

The study from Spain, for example, recorded where the fried food came from as well as how the fried food people consumed were cooked. The majority of fried foods the Spaniards 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-fat 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; heart disease, stroke, and heart failure; and cardiovascular mortality (Heart 2021;0:1-9. doi:10.1136/heartjnl-2020-317883).

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 food with those who consumed the least.

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

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

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

What this means for you

We 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"? - nor does it specify what foods were fried or in what type of oil.

That's information that's 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 food isn't quite as bad for you as it could be, the majority of the evidence still says that you're best off avoiding fried foods except for (very) occasional treats.

First posted: January 20, 2021