When man discovered fire 0.2 million years ago, everything changed.
Including the composition of our gut’s microbiome.
You probably know that the shape of our teeth has changed since then as well, because we aren’t gnawing on raw meat anymore. So it stands to reason that other areas of our internal operating system have evolved as well.
Cooking food activates chemical changes in the food itself, so that by the time that food reaches our digestive system it interacts differently with the microbes and bacteria in our biome than raw food would have.
And not all foods experience the same degree of chemical change when heat is applied – beef and sweet potatoes, for example, are more drastic examples of physical and internal transformation due to fire.
Furthermore, not much research has been done into exactly why cooking is said to improve the diet… at least, not until the massive raw food movement of the last few years. One solid theory is that cooking food increases its net value to the body in terms of energy, although even that varies between proteins, starches, and lipids.
In simple terms? Cooked food seems to give the body more energy than raw food.
Before humans were able to cook food with heat, they used non-thermal methods – like pounding – to affect the digestibility of their sustenance. This must have provided an energetic edge of raw food but…
It still couldn’t compete with cooked food. Cooked food has several distinct differences from its counterparts:
- Starch becomes gelatinized.
- Proteins’ molecular compositions are disrupted.
- Food-borne pathogens are eliminated.
Basically, what this means is that our digestive systems don’t have to expend quite so much energy to break down our food if it’s been cooked first.
Let’s take a look at what that does to the bacterial profile of your microbiome – raw vs. cooked.
Raw Food and the Microbiome
According to a study done recently on mice, raw food has an interesting effect on the microbiome.
When mice were fed a diet of raw sweet potato, by and large, their bacterial profiles were less diverse. As we know, the goal is to have an incredibly diverse array of bacteria.
They repeated the same experiment with raw white potatoes, beets, carrots, corn, and peas.
Although raw sweet potato and raw white potato both resulted in more homogenized bacteria, there was no change noted with the other raw vegetables.
Researchers explained this occurrence by noting that potatoes and sweet potatoes have higher quantities of digestible starch, which is more susceptible to transformation during the heated cooking process than the other vegetables.
Thus, eating those foods raw changes the way gut microbes react.
Cooked Food and the Microbiome
When the same experiment tested eight healthy adult men and women, by feeding them a diet of comparable raw and cooked meals over the course of three days and then testing their stool samples, their findings were in keeping with the mice.
Although gut microbiota was more diverse in humans after eating cooked food, there was less of a degree of difference between cooked vs. raw than there was in mice.
However, they also found that in mice, eating cooked food maintained weight whereas eating raw food initiated weight loss.
All members of the research team agree that further studies and analysis would be needed to solidify their findings, but the implications from this initial study are enough to draw a few conclusions…
Namely, that when the digestive system doesn’t have to work so hard at breaking down food, more of its bacterial population survives, and that certain foods are more important to eat cooked than others. That makes sense, right? You don’t normally chomp into a raw potato.
All in all, we owe a lot of our evolutionary prowess to the discovery of fire.
And it turns out that one of the ways cooking our food with fire helped us in the long run was to increase our energy input and decrease our energy output – a powerful tool we would do well to continue using!