study: cooked versus raw, does it make a difference?

Written by Gina Wren

Look, us mere mortals never really get to find out what is going on in the world of science. Well, not unless it’s (sometimes) sensationalised in the press. So, we wanted to bring you a snapshot of the latest science to whet your appetite to find out more if it’s something that piques your interest. Or, simply to keep you all in the “gut world” loop. Remember most of the studies are VERY new science, so keep your critical thinking cap on!

Our report is brought to you by our student research squad. They have their ears to the lab floor ground to keep us all informed.

 

Background

Diet can have a huge impact on the gut microbiota, outweighing even the effect of genetics. But the type of food you eat doesn’t explain everything about why your gut microbiota is so unique.

A new study published in Nature Microbiology is the first to investigate how cooking food changes the gut microbiota.

 

Type of study

This study was a randomised control study in mice. Mice were randomly assigned to the different dietary groups (raw vs cooked) and the study also looked at eight healthy human individuals in a crossover design, meaning each participant ate both the raw and the cooked diet in random order.

 

Study Findings

Researchers began by studying mice and whether cooked vs. raw beef and sweet potatoes affected the gut microbiota differently. Little difference was seen between the cooked and raw meat. But raw vs cooked sweet potato showed dramatically different changes in the microbiota. This was repeated with other types of foods with the most profound effects found in starchy vegetables.

The researchers also conducted a small human study where individuals ate raw or cooked plant-based menus for three days. Faecal samples were collected, and the microbiome profiled. Again, raw or cooked foods had different effects on the microbiota composition.

These differences may have been due to how the body and microbes break down carbohydrates but could also be due to chemicals found in the plants. For example, cooking sweet potato destroys antimicrobial compounds, Which would otherwise damage certain gut microbes.

This could suggest that the microbiota have evolved to adapt to a diet consisting of cooked food, Meaning raw foods aren’t necessarily the healthier option for us. Therefore it is important to consider how other aspects of our diet, such as cooking, could influence our gut health.

 

Conclusion

However, this research raises a lot of unanswered questions. Which foods should not be eaten raw? Let’s also not forget how different us humans are from mice too! The studies did not look at microbiota changes over longer periods of time. Larger and longer-term studies on humans are needed before we have a definitive answer on how cooking food impacts the gut microbiome.

 

About the Author

Gina Wren is currently a postgraduate student at Imperial College London focusing on the microbiome in health & disease.

She graduated from Durham University in 2016 after studying Natural Sciences. Following this, Gina worked at Innovate UK for two years. Helping to drive innovation and business growth in the health & life sciences industry.

 

Reference

Carmody RN, Bisanz JE, Bowen BP, et al. Cooking shapes the structure and function of the gut microbiome. Nat Microbiol. 2019. doi: 10.1038/s41564-019-0569-4.