Have you ever wondered what happens as the food you eat
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makes its way through your digestive system?
For the past few years, my focus has been nutrition, only to discover the journey toward utopia was really just a starting point. By all means, it’s the noblest of pursuit, but if we think that’s all there is, we’re doing ourselves a grave injustice. The most nutrient-dense foods in the world won’t help us a bit if we aren’t able to digest them properly.
So what exactly IS this incredible digestive system of ours?
From a 10,000 foot view, it’s a group of organs and glands, all working together to convert the food we eat it into nutrients our cells can use, as well as waste products our bodies eliminate.
The process is both mechanical and chemical. The chemical components happen as glands and organs secrete substances along the way (think enzymes, chemicals, & mucus). Chewing, grinding, and the churning that takes place in our stomachs offer examples of the mechanics.
If asked, I suspect most people would say digestion begins in the mouth, although the reality is it begins one step before, in our brains. Think for a moment about eating your favorite food, or coming home to the smell of something in the oven. Saliva, digestive juices, and enzymes will begin flowing simply by anticipating that food is on its way (ps: your heart rate and blood flow can even change!)
As your Sweetie takes tonight’s veggie dish out of the oven, you can’t help but take the first bite. Our mouths include teeth, tongue, taste buds, and salivary glands. Its primary job is to chew and liquefy food.
We all know what saliva is, but maybe not that it contains a couple of very important enzymes. The first is amylase, whose job is to break down carbs, which it does beautifully, all the way to the stomach where it’s inactivated by stomach acid. The second is lipase, an enzyme which helps break down fats. Although it’s found in saliva, this enzyme isn’t activated until it reaches the stomach (where fat digestion begins).
A couple of other cool items to note while analyzing the mouth. Our parotid glands, found behind our ears and jaw, are stimulated by the act of chewing. Among other things, they make hormones which stimulate the thymus to produce T-cells (which are the heart of our immune systems!). Also present in our mouths is mucin, secreted by the cells of our cheeks, which make food slippery so it can more easily slide down ..
This 9 – 10 inch long narrow tube extends from the mouth to the stomach. Peristalsis pushes food along, while the epithelial cells and mucus offer protection from anything that hasn’t been chewed well, is scratchy, too hot or too cold.
At the bottom of the esophagus is a one-way valve called the sphincter (aka, esophageal spinster or cardiac sphincter) whose main job is to keep stomach acid (and food!) from coming back up. While closed most of the time, peristaltic waves (triggered by swallowing) will cause it to relax, and allow food into
The stomach sits beneath our rib cage, just under our heart. It’s a pouch really, about the size of our hand, that’s folded over itself when empty. As we eat, it will expand, one rugae (fold) at a time. Its primary purpose in life is to be a blender. Chopping, dicing and liquifying food into something called chyme (a pea-soup-like liquid that’s a mix of gastric juices & food mash)
Since we’ve come this far, we may as well talk about some of the key hormones and secretions happening in the stomach. The first is gastrin, a hormone secreted by the G-Cells when food (especially protein) is present. It’s purpose twofold: to start the blender (get the food churning) and stimulate the production of gastric juices
Within the mix of gastric juices are enzymes, hydrochloric acid, hormones, and intrinsic factor. Protein is broken down in the stomach as the hormone pepsinogen, combines with hydrochloric acid turns into pepsin.
Once the food has been churned and broken down further, it’s ready to enter the small intestine, and the only way through is
the pyloric valve. Which separates the stomach from the duodenum (1st part of the small intestine)
** Have you noticed, up to this point we still haven’t DIGESTED anything (?!)
Finally, it’s here in the small intestine, that food (or at this point chyme) is completely digested and absorbed. Nutrients enter our bodies through small finger-like folds called villi. Not only do the villi let good things in, but they also keep foreign things out. For each nutrient, there is a specific part of the small intestine that is responsible for its absorption: the duodenum (first segment), jejunum (middle), and the ileum (last)
** Note: What happens when something has gone awry, and the villi aren’t filtering all of the bad things out?? Spend some time reading more about ‘leaky gut syndrome’ It’s often cited as the cause of food allergies, asthma, skin problems, migraines, fatigue <the list goes on and on>
After all of the nutrients have been absorbed, fiber, water, and bacteria pass through the ileocecal valve and onto
the large intestine and colon.
The colon is short (~ 3-5 feet) with a mission to absorb water, any remaining nutrients, and form stool. When it’s finally formed, it’s pushed to the descending colon and then into the rectum where it’s held until there’s enough volume to have a bowel movement.
Wait, don’t quit now! We still have to say a few words about a couple of key organs that lend support for all of this digestion. Beginning with ..
the pancreas, which actually wears two hats
The first is to produce hormones that help regulate our blood sugar. Insulin (secreted when blood sugar rises) and glucagon (when blood sugar is low). The second is to help with digestion by secreting enzymes that further help to break down starches and sugars, fats, and proteins.
The Gallbladder is also a critical player that stores and concentrates bile (produced by the liver). What makes bile so important? When you’ve eaten something with fat, bile is released into the duodenum. Once there, it helps break the fats, cholesterol, and fat-soluble vitamins into smaller particles. All of which gives lipase (the enzyme that breaks down fat) a greater surface area by which to work
Last, but certainly not least, is our liver, which boasts the title for the body’s most complex organ!
A few of the things it does related to digestion include breaking down toxins we’ve eaten with our foods, regulating the metabolism of carbs, fats, and proteins, it manufactures bile, makes and breaks down lots of hormones, regulates blood sugar level, and storage place for many nutrients. It also stores toxins like pesticides, herbicides, food preservatives, and dyes. (And that’s just scratching the surface!)
And so I share with you the latest assignment for my class on Digestion, as well as a recipe for a bowl of very special carrot soup.
Sometimes the most nourishing foods are also the simplest to make, and this beautiful soup is a shining example. All one needs are carrots, onions, ginger, cashews, and a few other spices you’re likely to have on hand.
The grated ginger lends this sweet carrot puree the perfect hint of heat and flavor. Don’t be tempted to skip the cashew cream. It’s a must. (The more I experiment, raw cashews amaze me with their versatility)
The soup comes together in less than an hour, prep included. It lasts nicely in the fridge for four or five days and freezes well.
~ Adapted from One Bite At A Time by Rebecca Katz
Carrot Ginger Soup with Cashew Cream
- 3 lbs carrots, washed, peeled and cut into 1" pieces
- 1 cup white wine
- 7 cups vegetable (or chicken stock) or cold water
- 1 ½ tsp sea salt
- 2 Tbsp coconut oil
- 2 ½ cups yellow onions, chopped
- 2 ½ tsp grated fresh ginger
- ½ tsp curry powder
- ¼ tsp ground cumin
- ⅛ tsp ground cinnamon
- ⅛ tsp ground allspice
- ⅛ tsp ground coriander
- 1 pinch red pepper flakes (more or less, depending on your tolerance for heat)
- ¼ tsp maple syrup, optional
- Cashew cream
- 1 cup raw cashews (preferably organic, soaked overnight and rinsed)
- 1 cup water
- 2 tsp fresh lemon juice
- ½ tsp sea salt
- pinch of freshly grated nutmeg
- Cashew Cream
- Soak the cashews in water for a couple of hours (or overnight). Drain and rinse the cashews
- In the bowl of a food processor, add cashew cream ingredients. Blend until smooth (~ 3 minutes)
- In a 6 - 8 quart pot, heat the coconut oil over medium heat.
- Add the onions, along with a strong pinch of sea alt and sauté until golden.
- Add the carrots and spices. Stir to combine.
- De-glaze the pan with 1 cup of white wine, and then add the remaining 7 cups (Magic Mineral Broth or cold water) and one more strong pinch of sea salt.
- Cook over medium heat until the carrots are tender (~ 20-25 minutes)
- In a blender or food processor, purée the soup in batches, adding the cooking liquid first and then the carrots.
- Blend until very smooth, adding additional liquid to achieve your desired thickness. Return to the pot, add the maple syrup and reheat slowly.
- To serve, ladle the soup into bowls and swirl the cashew cream throughout. Top with pumpkin seeds and curly parsley
The “extra” toppings on this one are really critical to elevating this one to seriously yummy!
I honestly had no clue about the hormones like gastrin that are secreted when food makes its way through our digestive system. That was an interesting read and this soup looks divine x