processed food – what do we mean?

To some extent, a lot of the food we consume has been processed in some way or another, whether it’s ready sliced veg for a stir fry or a tin of tomatoes and in many ways such processing is beneficial. What we are really interested in (as are the scientists) is the effect of ultra-processed foods on our delicate community of microbes. With so many definitions whizzing around and myths surrounding ‘processed’ foods, like if its got more than 5 ingredients then its bad for you, it’s no wonder we can get confused. What is an ultra processed food? Lucky for us, the NOVA classification system neatly categorises food into the following groups:

1. unprocessed or minimally processed foods;
2. processed culinary ingredients;
3. processed foods; and
4. ultra-processed foods

Ultra-processed foods (UPF) are snacks, drinks, ready meals and many other products created mostly or entirely from substances extracted from foods or derived from food constituents with little if any intact food. These typically contain emulsifiers, flavours, colours and other additives that make UPF more palatable.

UPF are typically cheap, offer convenience and have a long shelf life, but can have a negative effect on our health and that of our microbes due to their energy density, high fat, salt and or sugar content and are thought to contribute to the rise in obesity we are seeing worldwide with the increase in global food production.

How does this effect our gut?

• UPF may get in the way of our gut-brain-axis and interfere with our sensitive feedback mechanism that tells us when we’ve had enough.
• A diet high in UPF may be lower in fibre and plants, which is a key risk factor when looking at the incidence of metabolic disease like type two diabetes.
• UPF create changes to the gut and its microbes, which promotes inflammation and creates an environments that increases the risk of neurodegenerative diseases (like Alzheimer’s or Parkinson’s) and general cognitive decline.

Next time you are reaching for the ready meal with months left on its shelf life, maybe give your microbes a thought and check out our easy to make recipes on the site.

References

1.  González Olmo BM, Butler MJ, Barrientos RM. Evolution of the Human Diet and Its Impact on Gut Microbiota, Immune Responses, and Brain Health. Nutrients. 2021 Jan 10;13(1):196. doi: 10.3390/nu13010196. PMID: 33435203; PMCID: PMC7826636.
2. Hall KD, Ayuketah A, Brychta R, et al. Ultra-Processed Diets Cause Excess Calorie Intake and Weight Gain: An Inpatient Randomized Controlled Trial of Ad Libitum Food Intake [published correction appears in Cell Metab. 2019 Jul 2;30(1):226] [published correction appears in Cell Metab. 2020 Oct 6;32(4):690]. Cell Metab. 2019;30(1):67-77.e3. doi:10.1016/j.cmet.2019.05.008
3. Martínez Leo EE, Segura Campos MR. Effect of ultra-processed diet on gut microbiota and thus its role in neurodegenerative diseases. Nutrition. 2020 Mar;71:110609. doi: 10.1016/j.nut.2019.110609. Epub 2019 Oct 11. PMID: 31837645.
4. http://archive.wphna.org/wp-content/uploads/2016/01/WN-2016-7-1-3-28-38-Monteiro-Cannon-Levy-et-al-NOVA.pdf
5. Shi Z. Gut Microbiota: An Important Link between Western Diet and Chronic Diseases. Nutrients. 2019;11(10):2287. Published 2019 Sep 24. doi:10.3390/nu11102287
6. Small DM, and DiFeliceantonio AG (2019). Processed foods and food reward. Science 363, 346–347.