- Even a small portion of fried foods can take a toll on heart health, a study found.
- One medium McDonald’s fries per week was enough to increase heart disease risk.
- Fried foods are high in trans fats, and they can decimate an otherwise healthy diet.
- Visit Insider’s homepage for more stories.
A new analysis of studies quantified just how bad fried foods are for your health. It turns out even a half-cup of the stuff – or a medium McDonald’s french fry serving – is enough to increase your risk of heart disease and associated cardiovascular events.
The meta-analysis, published Monday in the journal Heart, summed up 17 studies that investigated the relationship between fried food and heart health.
A half-cup, or 4 ounces, of fried food each week is associated with a 3% increased risk of heart attack and stroke, a 2% increased risk of heart disease, and a 12% increased risk of heart failure, the analysis found.
That risk climbs with each donut or cruller you add to your weekly intake. People who ate the most fried food per week had a 37% higher risk of heart failure compared to those who ate the least, along with a 28% greater risk of major cardiovascular events and a 22% increased risk of heart disease.
“While this study determined a link between cardiovascular disease and fried foods, these findings are not able to establish a direct link,” Megan Meyer, PhD, director of science communications at the International Food Information Council, wrote in a statement to Insider.
That means more research needs to be done to say whether eating fried foods directly causes heart disease. Long-term studies in particular would help shed light on the relationship between fried food intake and mortality risk, which was murky given the available evidence.
Fried foods contain extra trans fats
Not only do fried foods often contain extra sugar and sodium to make them dangerously tasty, but they also soak up some of the fat from the oil they're cooked in. That oil likely contains trans fats, an especially unhealthy kind of fat that's cheap to make and helps food last a long time.
Trans fats are overwhelmingly bad for your health, so much so that the FDA banned them in 2015. Trans fat intake is associated with the heart problems noted in the recent analysis, as well an increase in bad cholesterol (LDL) and a decrease in good cholesterol (HDL).
"We know that frying food can degrade its nutritional value, generate trans-fats which are known to be harmful, as well as increasing the calorie content of the food, all of which eventually lead to processes that can cause heart disease," cardiologist Riyaz Patel of University College London said in a statement.
However, the FDA still allows companies to label a food as trans fats-free if one serving of the food contains less than 0.5 grams, which can add up if people eat multiple servings of food over time.
Eating unhealthy foods can ruin an otherwise healthy diet
Unfortunately, eating healthy most of the time won't make up for your French fry habit.
A separate study, published in the journal Alzheimer's & Dementia earlier this month, found that eating fried foods, sweets, and other unhealthy snacks may diminish the health benefits of the Mediterranean diet.
The Mediterranean diet, which is rich in vegetables, fruit, fish and whole grains, is known for being flexible and easy to follow. But dieters need to adhere to the guidelines in order to reap the health benefits, which include better cognitive health and a decreased risk of chronic disease and overall mortality.
In the study, people who adhered closest to the Mediterranean diet saw the most benefits to their cognitive health, while those who also indulged in unhealthy Western foods may as well have been not dieting at all.