Doctors have told us for decades that ultra-processed food is bad for our health. However, as we get bombarded daily with messages about “whole foods” and “clean eating,” it can be hard to take it all in. When you’re tired or pressed for time, eating processed snacks and meals can feel unavoidable. New research, from two separate studies, shows that processed food is more damaging to health than previously realized. The discoveries may change the way we approach our meals and may prompt us to cut out snacks.

More research will be necessary to identify the direct link. They can see the results of eating processed foods, but not the actual reason why it’s so damaging.

In Spain, 19,899 people were studied for 10 years. Eating more than four servings of ultra-processed foods a day was associated with a 62 percent increased risk of all-cause mortality when compared to people who ate less than two portions a day. Each additional serving upped the risk by 18 percent. Meanwhile, in France, a study of 105,159 people for ten years showed that a 10 percent increase in the proportion of ultra-processed in a person’s diet significantly increased the person’s heart health risks. For every 10 percent increase, the risk of overall cardiovascular disease was upped by 12 percent, for coronary heart disease it was raised by 13 percent and for cerebrovascular disease there was an 11 percent increase.

These significant results were seen even after accounting for lifestyle, age and income. Because the study was observational, the reaction in the body that’s causing these results isn’t apparent. “There is an association between the consumption of ultra-processed foods and an increased risk of cardiovascular diseases, when all lifestyle factors were accounted for, and these associations are not fully explained by the nutritional quality of these ultra-processed foods,” lead author Bernard Srour of the Univ. of Paris.

Some scientists think the increased risks, may be because of how the food impacts an individual’s microbiome in their gut. Observation has shown that a higher abundance and a greater variety of bacteria in the gut is better for health. “Diet is the number one influencer and determinant of our gut microbiome composition,” said Suzanne Devkota, director of microbiome research at the Cedars-Sinai F. Widjaja Foundation Inflammatory Bowel and Immunobiology Research Institute. She is researching how processed grains, meats and sugars impact the microbiomes of mice. Comparing the bacteria in mice eating a diet like a person eating ultra-processed food vs. mice consuming a diet far higher in fiber, they saw that the mice eating the processed food-like diet had fewer bacteria in their microbiome and less diversity in that bacteria. Few studies of microbiomes have been performed in humans. But what little research has been done agrees with the mouse models.

“The thing you can generally say is that in states of health, the microbiota has a high level of diversity in a wide variety of different species,” said Andrew Gewirtz, a professor at Georgia State Univ.’s Center for Inflammation Immunity and Infection. “And a lot of these [bacteria] tend to get lost in diets that are highly processed.”

This lack of bacterial diversity may be caused by the additives and emulsifiers used in processed foods. Studies dating back to 2015 have shown that emulsifiers may have a negative impact of the gut, worsen inflammation, may cause increased hunger and drive overeating. Overeating can, in turn, impact the heart.

The category of ultra-processed food isn’t just populated by chips, candy and soda. Other ultra-processed foods include packaged bread, premade meatballs, frozen fish stick and the like. These are all things we might think of as staples or normal without really considering how they are made. “Considering [these] studies have shown associations between ultra-processed food consumption and other health outcomes, people should limit the proportion of ultra-processed food in their diet and privilege the consumption of unprocessed and minimally processed instead,” said Srour.

While cutting out all ultra-processed food might be a task that seems monumentally hard to achieve, cutting back might be a significant step toward a healthier heart and gut.