A Guide to Good Digestion.
Part 3: The Liver, Gallbladder and Pancreas.
Welcome to my third instalment of A Guide to Good Digestion. In the first instalment, I wrote about the role that the mouth plays in effective digestion, and the importance of chewing. In the second article I wrote about the role of the stomach, and the importance of having strong hydrochloric acid in your stomach.
So let’s get right into it: the Liver, Gallbladder and Pancreas. These three organs collaborate just after the stomach at the top of the small intestine to break down macronutrients and activate micronutrients. Don’t worry, I’ll explain what that means soon! To break down the partially digested food that has made it all the way to the liver, gallbladder and pancreas, these three organs all use chemical digestive processes. Quick recap: chemical digestion includes acids and enzymes breaking down food into nutrients, and mechanical digestion includes chewing, and stomach muscles mashing foods into effectively digestible forms. So the liver, gallbladder and pancreas all work together to chemically digest food into small, absorbable nutrients.
Now, a quick explainer on macro- and micro-nutrients. Macronutrients are just clusters of micronutrients strung together. There are three macronutrients: Lipids, Carbohydrates and Proteins. Lipids are made of fatty acids, carbohydrates are sugar molecules, and proteins are made of amino acids. The body needs the gut to break these macronutrients down into smaller micronutrient forms so that they can be absorbed into the blood.
So, summing up so far, we have three organs (liver, gallbladder, pancreas), that use enzymes to break down three macronutrients (fats/lipids, carbs, and proteins) into micronutrients which are absorbed into the blood.
Now, I’ll explain how these organs help activate these micronutrients and detoxify the byproducts.
Liver and Gallbladder
The liver is a huge triangular organ (weighing 1.5kg) which takes up most of the upper-right abdominal space. The liver is incredibly multi-functional and vital to our bodily function. Most people I talk to solely think of drug and alcohol consumption and the role the liver plays in detoxing these from the body. However, the liver does so much more! In particular, the liver plays a huge role in digesting and absorbing nutrients into the bloodstream.
The liver interacts with macronutrients in many different ways.
Firstly; it converts some macronutrients into micronutrients ready to be absorbed into the bloodstream. If it can’t convert them directly, it helps to prepare the macronutrients into forms digestible to the enzymes in the small intestine, so the small intestine can turn the macronutrients into micronutrients.
Secondly, the liver works as a filter for our blood, ensuring that the valuable nutrients enter our bloodstream while toxins are filtered out. After the macronutrients have been converted into micronutrients in the liver and small intestine, the small intestine pumps out newly micronutrient-rich blood into the bloodstream. This travels around the body, delivering these nutrients to target organs and nutrient receptors from head to toe. As blood passes through the liver on its way around the bloodstream, the liver performs the vital function of ensuring that useful micronutrients remain in the blood, while waste products are removed.
The liver filters nutrients into three categories: molecules to be absorbed, stored or detoxified. In the first category, the liver recycles (or absorbs) useful nutrients back into the blood to be used to nourish the body. Other substances are stored in the liver (that’s the second category) for the body to use only when needed in the future. Finally, the liver detoxifies a range of molecules which are toxic or not needed to nourish the body. These can be excess nutrients, hormones or byproducts of reactions that have occured around the body. In any case, the liver removes them from the blood, and helps them to exit the body via the bowel or as urine, sweat, or tears. Other toxic molecules such as heavy metals, plastics and excess sugar are stored as fat.
But I can’t talk about the role of the liver without including the gallbladder, because the liver and the gallbladder work in combination, forming a great team called the Hepatobiliary System. The gallbladder is tucked up inside the bottom of the liver and is infamous for housing painful gallstones. The gallbladder isn’t just home to these nasties, it also deserves credit for the role it plays in breaking down fats (remember fats are called lipids - one of the three macronutrients). The gallbladder is where bile is concentrated, stored and released into the small intestine. For those of you wondering, bile is a dark green fluid made by the liver. This acidic, green fluid is what breaks down the fats we eat, unlocking the good stuff! I’ll explain in a little more detail in soon!
So to recap, the liver is busy and has it’s trusty gallbladder there to assist it. It activates nutrients to allow the gut to digest and absorb them into the bloodstream. It also filters blood to absorb, store or detox certain components of the blood. The gallbladder is a storage and release site for bile.
The pancreas contains a liquid or “pancreatic juice” made up of digestive enzymes, including pancreatic amylase, trypsin and so on. The pancreas is located just across the road (small intestine) from the liver, and beneath the stomach. It is bumpy and elongated in shape and often pictured as green in text books, although in real life it’s not so brightly coloured! The pancreas usually gets a lot of attention in the media for the role it plays in diabetes, because it releases insulin which is needed for glucose (sugar) to enter inside cells. However, 90% of the role of the pancreas is making that “pancreatic juice” to digest fats and proteins (don’t forget, most of the carbohydrates are digested and absorbed before even making it to the small intestine). The pancreas combines with bile from the gallbladder to effectively snip nutrient chains. Teamwork!
Now that we’ve figured out the role of those three great organs (the liver, gallbladder and pancreas) let’s take a bit more of a look at the process of digesting the three macronutrients we mentioned before: fats, carbs, and proteins.
The gallbladder releases stored bile, made in the liver, to prepare fats to be transported in the blood. To put it simply, bile does not digest fats but rather emulsifies fats so they then can be digested by enzymes in the small intestine. The liver allows fat-soluble vitamins such as Vitamins A, D and E to be absorbed into the bloodstream. These vitamins are great for supporting the body’s immune system!
The main aim here is to turn sugar molecules into glucose, then to convert glucose into glycogen which can be used for energy. The liver metabolises carbohydrates through a process called gluconeogenesis. Now that’s one for your spelling list! This process entails breaking down long/complex sugars such as fructose and galactose into a small and simple sugar called glucose.
The gallbladder and liver alter the shape of protein molecules (a process called denaturation) to then send to the pancreas so it can finish the job of releasing those amino acids. Proteins need to be broken down into amino acids for the body to be able to use them. During the process of this breakdown ammonia is made, this is a toxic byproduct. The liver protects the blood from ammonia by either detoxing it out of the body or storing it in fat cells. In short, the liver makes protein digestion easier on the pancreas and less toxic for the body.
Now that our accessory organs have digested, absorbed and detoxified all the macronutrients we just ate, our body can get on with it’s natural functions. Using fatty acids, sugars and amino acids to build our physical form, release chemicals to make us happy and calm and support our metabolic processes throughout our entire body.
I hope you have made your way safely down past your “accessory organs”. See you next time for a journey into your small intestine.
Lydia Irving is a practicing nutritionist (BHsC) who consults clients in Forster and Taree. Through her business, Internal Instinct, Lydia also offers personalised supplement formulas, and sourdough and fermentation workshops. Lydia specialises in helping clients to understand their health concerns and looks for underlying causes of disease rather than just treating symptoms. For more information and enquiries, contact.
For Forster consultations Lydia is located at Forster Yoga Studio, Forster Towers, Level 1
10-12 Wallis Street, Forster
For consultation enquiries in Taree
Lydia Practices out of Spectrum Natural Family Health Care in Taree on Monday afternoons.
02 6550 1223