Nutrition 101 – Digestion Basics
Having a healthy digestive system is really the foundational aspect of health. You can eat all the amazing, nutritious food out there, but if you aren’t digesting those nutrients properly then you aren’t gaining any of their benefits! While studying to become a Nutritional Therapy Consultant, digestion was the first major process we covered, and throughout all the more advanced topics it’s also the process that you always come back to. Often just by working on improving your digestion you can already make major strides in bringing your body back into balance.
What does healthy digestion look like?
It starts in the Brain
The first, very important step of digestion actually starts in our brains! It’s the resulting chemical cascades as we start thinking about our meal. Our brain triggers the acid production to increase in our stomach (creating that “growling” you can experience) and you might already start salivating as your saliva glands get ready to start breaking down your food.
And then in the Mouth
Then we get into the actual eating! The first step of really digesting your food happens in your mouth. Your teeth, by chewing, already start breaking everything down in smaller bits that will be easier to digest further on in the process. Your saliva also contains digestive enzymes that begin the chemical breakdown of carbohydrates. Bet you didn’t know so much was going on in your mouth!
The Stomach gets involved
After you swallow, the food (now called the bolus) passes down your esophagus and into your stomach. Here your stomach acid is on deck to continue the chemical breakdown of your food. Your stomach acid, and specifically an enzyme called pepsin, is vital in proper digestion of proteins. The muscles of the stomach are churning the bolus, mixing it with the stomach acid to properly break down and acidify it.
Before moving to the Small Intestine
Once the bolus reaches the proper acidity, it is now called chyme, and it moves from the stomach into the first part of the small intestine. This entry signals our small intestine to secrete mucous and our pancreas to release sodium bicarbonate which alkalinizes the chyme (in other words, makes it less acidic). The presence of fats in the chyme triggers the gallbladder to release bile, which emulsifies and breaks down the fatty acids. Once the chyme is no longer acidic, the pancreas will release enzymes that finish the digestion of the carbohydrates, proteins, and fatty acids.
The chyme continues further on along the small intestines, and now that your food is properly broken down, little villi and microvilli (like little fingers lining the small intestines), begin to absorb the nutrients and pass them through your gut lining into the bloodstream.
And finally the Large Intestine
Eventually the remains pass into the large intestine, where the remaining water is recycled and waste products are used to nourish the microbiota of the large intestine. The remaining nutrients from your food are captured and your bowel flora also create some nutrients of their own for your body to use. Once this process is complete, what remains then passes out of the large intestines and, well, out of your body! (I think we all know this part of the process!).
So that is a brief overview of what healthy digestion looks like. But of course, as many of us have probably experienced, it is easier said than done; there are a lot of different ways our digestion can become suboptimal.