I recently reported on a UK-based study which found that eating ultra-processed foods was associated with a higher risk of developing cancer, particularly ovarian cancer, breast cancer and brain cancers (EClinicalMedicine, Jan 31, 2023 31;56:101840). Now the French NutriNet-Santé cohort study has strengthened the association between processed foods and heart attacks even more (BMJ, September 6, 2023;382:E076058). Their results suggest a link between the dietary intake of emulsifiers and an increased risk of cardiovascular disease.
The study included 95,442 people, with an average age of 43 years and 79 percent of them female, and analyzed their consumption of emulsifiers. Emulsifiers are among the additives most widely used by the food industry to improve the texture and taste of foods and extend their shelf life. In North America, more than 50 percent available foods contain emulsifiers (Sci Rep, 2020;10:3980).
Emulsifiers and Gut Bacteria
Look at the list of ingredients on packaged foods and you are likely to see emulsifiers such as cellulose, monoglycerides and diglycerides, modified starches, lecithins, carrageenans, phosphates, gums and pectins. One of the functions of emulsifiers is to hold food ingredients together. For example, mayonnaise without emulsifiers would separate into an oily top layer and a thick white lower layer.
Emulsifiers have been reported to increase the number of harmful bacteria in human colons (Microbiome, 2021;9:66). These bacteria try to invade colon cells. Your immune system responds by producing large amounts of cells and proteins to kill the invading bacteria (inflammation). If your immune system stays active all the time, these same cells and proteins can attack you to damage your cells to form plaques in arteries. The plaques can then break off to cause heart attacks. Inflammation can also damage the DNA in cells to cause cancer.
The French study quoted above found that the emulsifiers were associated with increased risk for heart attacks. An earlier study on mice showed that emulsifiers disrupted intestinal bacteria to cause inflammation and weight gain (Nature, Feb 25, 2015). Researchers fed emulsifiers (carboxymethylcellulose and polysorbate) at doses comparable to what humans eat in processed foods, to mice for 12 weeks. The mice’s gut bacteria penetrated into the intestinal lining, instead of staying on the surface where they belong. This turned on the mice’s immunity against the bacteria, demonstrated by the presence of proteins that are signs of an overactive immune system.
A healthful diet involves more than just eating lots of fruits, vegetables, whole grains, beans and nuts. Try to eat most of these foods as they come to you in nature, so you can see whole plant parts — leaves, stems, roots, seeds and fruits. Eating a lot of foods that come in packages increases your risk for foods that have been altered in ways that can harm you. Get most of your calories from nutrient-rich unprocessed or minimally processed foods, and limit foods that have been processed with added chemicals.