Digestive enzymes are necessary to digest food
[UPDATED JUNE 2022]
Digestive enzymes are necessary to breakdown and digest foods so that they can be absorbed. They need the right amount of acid in the stomach, the right amount of alkali in the duodenum, and the right amount of time spent in each department so that these enzymes can work. Failure to digest foods properly results in foods not being broken down and causing problems downstream. These problems arise because the foods get fermented instead of being digested, worse, the foods may simply not be absorbed at all and pass out in the faeces.
- Poor digestion of starches results in fermentation by yeast and bacteria downstream, which results in wind, gas and bloating.
- Poor digestion of fats results in high level of fat in the stool, which can result in the loss of fat soluble vitamins, namely A, D, E and K.
- Poor digestion of proteins results in short chain polypeptides being absorbed into the bloodstream where they can seriously disregulate normal biochemistry by mimicking biologically active proteins. So, for example, short chain polypeptides may mimic hormones which control blood pressure such as vasopressin and bradykinin. Worse, they may appear to the immune system as a foreign invader. Should the immune system make antibodies against them then this could set up allergies to foods and/or autoimmunity. Thus good efficient digestion of food is vital for normal health and prevention of disease.
Digestion starts in the mouth
Digestion starts in the mouth where foods are broken down into small particles in order that enzymes can get at them. Saliva is rich in amylase, which starts the digestion of starches. Gandhi told us we should chew our liquid and drink our solids! A slight overstatement perhaps, but this does make the point that we should take time to chew food thoroughly because then the whole digestive process is greatly facilitated downstream. Furthermore saliva contains endothelial growth factor - this stimulates tight junctions between cells and prevents leaky gut. See also the Great Masticator - Horace Fletcher, who argued that food should be chewed about 100 times per minute before being swallowed:
"Nature will castigate those who don't masticate" - See Wikipedia article on Horace Fletcher
Gastric Acid Deficiency - see Hypochlorhydria
The stomach is remarkably acid and this is vital in order to sterilise the contents of the stomach (and thereby guard against infections), in order to absorb minerals (and hypochlorhydria is a major cause of iron deficiency anaemia) and essential for protein digestion since protolytic enzymes can only function in an acid environment.
Hypochlorhydria is easily treated by taking hydrochloric acid with food and this is usually given with Pepsin, the enzyme necessary to digest protein. As we age we are more likely to develop - please see Hypochlorhydria
Pancreatic enzyme deficiency
The pancreas is responsible for producing enzymes to digest protein, fats and carbohydrates and these work best in an alkali environment. The alkali is supplied as sodium bicarbonate, but from the liver via the bile ducts together with bile salts. Biles salts emulsify fats so the enzymes can get at them (like a detergent) and also help sterilise the upper gut. Poor pancreatic function therefore is associated with poor digestion of all foods. This process takes place in the duodenum and jejunum and this part of the gut should be free from bacteria. Digesting foods with enzymes does not produce wind or gas.
Poor pancreatic function can be assessed by a Comprehensive Digestive Stool Analysis, which includes measurement of fats in the stool, looks for meat fibres (their presence indicates poor protein digestion), and also looks for chymotrypsin (to digest protein) and long chain fatty acids and short chain fatty acids. As an extra you can ask for pancreatic elastase and bile salts - please see Elastase - a new test for pancreatic disease.
Many people with food allergies are also deficient in stomach acid and pancreatic enzymes. See The influence of gastric digestion on the development of food allergy
There are many pancreatic supplements on the market. I tend to use the BioCare Polyzyme Forte, but there are many different products available. I have heard that the prescribed form of pancreatic enzymes contain toxins such as pthalates and methacrylatte - so avoid!
Digestion of foods in the small intestine
The small intestine continues the process of digestion and various enzymes are present there to break starches down further. These enzymes are called disaccharidases. The best known is lactase, which is the enzyme necessary to digest milk sugar. This enzyme is normally present in all young mammals who need this to digest mother's breast milk. With age and as breast feeding finishes, production of this enzyme ceases for life. Interestingly most Caucasians retain production of this enzyme and this allows them to tolerate eating dairy products. Fermented milks such as yoghurts have had the milk sugar digested out and can be tolerated where fresh milk is not. Lactose intolerance is almost universal following acute gastroenteritis because the cells that make lactase are lost when the bowel is acutely inflamed.
However, it is my view that dairy products are not evolutionary correct foods - they cause all sorts of problems other than intolerance of lactose. They are associated with an increased risk of heart disease and cancer and are common allergens and should generally be avoided. Please see The Paleo Ketogenic Diet - PK Dairy
Fructose intolerance is not caused by enzyme deficiency in the gut, but an enzyme problem in the liver which means fructose cannot be adequately dealt with. When this occurs, fructose can inhibit the mechanisms by which the liver makes glucose from fats and proteins (to biochemists - this is called gluconeogenesis). The point here is that eating fructose can result in severe hypoglycaemia because as blood sugar levels fall, the liver is unable to correct them. For further information see Hypoglycaemia
This problem is described in Enzyme deficiencies causing gut symptoms in this section, or use link.
- Pancreatic exocrine function
- The Paleo Ketogenic Diet - PK Dairy
- Enzyme deficiencies causing gut symptoms
- Wikipedia article on Horace Fletcher
- The influence of gastric digestion on the development of food allergy
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