The proper digestion and metabolism of dietary protein yields amino acids, which are used by your body as building blocks to make protein-rich tissue such as muscles, skin and hair. A lack of amino acids typically results in muscle weakness, skin blemishes, dull looking hair, brittle fingernails and reduced immunity. There are many simple and inexpensive things you can do to help your body digest protein well.
Foods have different digestive rates depending on their composition. For example, protein-rich foods such as beef, poultry and fish spend about three or four hours in your stomach, whereas fruit and veggies typically spend less than an hour. This is because protein digestion begins in the stomach and takes more time than digestion of carbohydrates, which are found in fruits and vegetables. Problems happen when you mix protein-dense food with lots of fruit and veggies because it sort of confuses your stomach. A mixture of protein and carbohydrates might only spend two hours in your stomach, which is too little time for the protein component and too much time for the starch and other polysaccharides to get digested effectively. As such, don’t combine other food groups when you eat protein. This ensures more time for protein to get digested in the stomach.
Your stomach needs to be quite acidic in order for protein digestion to start. The primary protein enzyme in your stomach is pepsin, but it isn’t activated unless the stomach juices are below a pH measurement of about 3.0. If your stomach releases enough hydrochloric acid to lower the pH to that level, then the pepsin starts to break down the collagen tissue that holds the long peptide chains together in the meat. To ensure that your stomach is acidic enough and not too dilute, don’t drink a lot of fluid, especially milk, with your meals. Furthermore, to enhance your stomach’s acidity before a meal, take a few spoonfuls of apple cider vinegar or fresh lemon juice.
The majority of protein digestion happens in your small intestine with the help of protease enzymes. Trypsin and chymotrypsin, which are the enzymes released from your pancreas, break the long peptide chains into single amino acids, which are then absorbed through the wall of the small intestine and carried to the liver for further processing. Sometimes, either due to disease, infection or injury, the pancreas doesn’t produce enough digestive enzymes. In these situations, supplementing with protein enzymes is often helpful. Two excellent natural sources of protein enzymes are papaya and pineapple. Papaya contains papain, whereas pineapples are rich in bromelain. After a protein-rich meal, wait a little while and then eat some fresh papaya or pineapple for dessert in order to promote better digestion
In addition to risking an amino acid deficiency, undigested protein sometimes causes a severe reaction. When small amounts of undigested protein get absorbed through a “leaky” stomach or intestine, your body assumes it’s being attacked by a foreign invader. Consequently, your body mounts a major immune defense reaction, which triggers lots of inflammation and often leads to a diagnosis of food allergy or autoimmune condition. If your gut is healthy and doesn’t leak, then undigested protein usually just causes gas, bloating, flatulence and diarrhea.
- Contemporary Nutrition: Functional Approach; Gordon M. Wardlaw et al.
- Encyclopedia of Human Nutrition; Benjamin Caballero et al.
- Textbook of Nutritional Medicine; Melvyn Werbach and Jeffery Moss
- Public Health Nutrition: From Principles to Practice; Mark Lawrence and Tony Worsley
Sirah Dubois is currently a PhD student in food science after having completed her master's degree in nutrition at the University of Alberta. She has worked in private practice as a dietitian in Edmonton, Canada and her nutrition-related articles have appeared in The Edmonton Journal newspaper.