Chronic inflammation and disease that starts in the gut

This column is written by Stig Bengmark – professor emeritus, researcher, lecturer and author. Read more of Stig’s columns here.

The degree to which a food has been refined determines where it will be absorbed by the body

All the food we eat leaves the gut sooner or later and enters the blood for transport to the body’s cells. So far, so good. The question is where exactly in the gut the food is absorbed – early, in the small intestine, or 3-4 hours later in the large intestine?

The longer the food remains in the intestines the better, and it is the degree to which the food has been refined that determines where it is absorbed by the body. Industrially processed foods, which have been heavily processed by the food industry or – more commonly – in our own kitchens, is so processed that it is absorbed very quickly, high up in the small intestine. And this does not benefit the body.

Unrefined foods, on the other hand – raw fruits, vegetables and root vegetables – are so difficult to digest that most of it is transported down a conveyor belt for 3-4 hours on its way to the large intestine, where it is broken down by the intestinal flora (microbiota). This is always desirable. This conveyor system has dominated the gut for millions of years, and about 80% of the food we eat was absorbed into the body this way.

So, why is it better that our food is absorbed in the large intestine?

When unrefined food, which is more difficult to digest, reaches the large intestine, it also nourishes the beneficial, health-promoting bacteria that prosper in your gut and allows the beneficial microflora to multiply. This allows the colony of beneficial bacteria to perform their vital functions, which are absolutely necessary for optimal health:

  • Suppressing any dominance of malicious, disease causing bacteria. If the malicious bacteria are instead allowed to dominate undisturbed, they release toxins into the body or even enter the body themselves. Once in the body, they create inflammation with all the undesirable conditions that go along with it, i.e. obesity and acute and chronic diseases.
  • Stimulates the immune system. The majority of the immune system is in the gut – this is where most of the body’s immunoglobulins (antibodies) are produced and where the body’s immune cells are “educated” for the functions they serve around the body.
  • Releases beneficial substances from the plants we eat, e.g. a variety of short-chain fatty acids, amino acids, vitamins and antioxidants, which are absorbed and will nourish the body.
  • Supplies energy to the body, e.g., sugar, but in a way that is more in line with the body’s needs – “slow release” – instead of the “shock” that occurs when refined sugar is eaten and arrives in large quantities high up in the small intestine.

Why is it so bad when food is absorbed early, in the small intestine?

If the food is instead absorbed early on in the small intestine, you lose out on all the above health benefits. It is also associated with many disadvantages that, over the long run, are directly life-threatening, as it:

Places excessive strain on the digestive organs, e.g., the liver and pancreas, which are forced to work under high pressure to get rid of the excess sugar in the blood as soon as possible. This is tremendously harmful to the body and its cells.

Creates chronic inflammation and, over the long term, contributes to obesity and chronic diseases, especially diabetes and Alzheimer’s.

Creates conditions for poorly functioning gut flora and impaired immune system thereby leading to susceptibility to colds and other acute and chronic diseases.

With today’s Western diet, 60% of the food we eat is absorbed in the small intestine

Simply put, the fact that modern food is refined by the food industry and/or our in own kitchen thereby doing the work that has been done by our gut bacteria for millions of years and is absorbed early in the digestive tract, high in the small intestine, is not a good situation at all. While this shortcut was only used by a fraction – less than 15% – of the food our ancestors ate, it has now become the main route for all the sugars and sugar-like foods we put in our bodies – as much as 60% of the food we eat today is absorbed in the small intestine.

For optimal absorption in the large intestine, we need to eat more according to the 80/10/10 model – 80% raw vegetables, 10% vegetable fats and 10% vegetable protein. This greatly benefits our protective gut bacteria.


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