Journal Club

Ultra-processed foods and food additives in gut health and disease

Authors

Kevin Whelan, Aaron S. Bancil, James O. Lindsay, & Benoit Chassaing

publication

Nature Reviews Gastroenterology & Hepatology volume, 2024.

With so much attention in the news and wellness websites warning about the dangers of ultra-processed food (UPFs), what is the evidence for actual badness for the gut?

This review paper highlights findings from epidemiological, preclinical (e.g. laboratory animal) and human clinical studies investigating the effects of components of ultra-processed food on measures of gut health.

Main Takeaways

  • Epidemiological studies (descriptive studies of groups of many people) reliably link ultra-processed food consumption with inflammatory bowel disease, colo-rectal cancer, and irritable bowel syndrome. The article does not mention it, but such studies also link “Western diet” which is made up largely of ultra-processed foods, to food allergies and celiac disease as well.
  • The article points out that there are also many preclinical studies showing adverse effects of food additives, such as emulsifiers, sweeteners, and colors, on aspects of gut health including gut microbes, intestinal permeability (leaky gut) and inflammation.
  • Unfortunately, at this time there is very little information for humans, and most studies that have addressed the issue of ultra-processed food and the gut have involved people with inflammatory bowel disease. A few such studies have shown that restricting diets to avoid ultra-processed foods can be helpful for disease management, but it is clear we need more studies with more standardized outcomes to be able to make useful specific recommendations. Apparently, there are such studies now underway, and hopefully some with a broader patient population.
  • The authors also point out how difficult it is to do useful research, given the wide variety of additives and processing techniques that are involved in ultra-processed food.

Dr. Goehler's thoughts

Taken together, this review of studies reinforces the idea that for gut health, intake of artificial ingredients, including sweeteners and emulsifiers, should be limited. But there is still a ways to go before specific recommendations can be made.