Food intolerance in the UK is increasing. Food intolerance most frequently manifests as a digestive disturbance or self-reported ‘allergy’ to food. It is estimated that approximately 30% of the UK population will report a negative reaction to food, but only 2% of the population will have a true allergy. [1] Food intolerance can be described as the body’s inability to accept a particular food or some of its molecules.
The most commonly reported food intolerances are gluten, lactose, fructose, carbohydrates and phenols. [2][3] These foods have molecular structures that require chemical digestion via digestive enzymes[4]. Foods that pass through the stomach undigested can generate unwanted reactions. Effective digestion will break food molecules into smaller molecules that are less likely to generate an adverse reaction.
Digestive enzymes are generated by the pancreas, stomach, small intestine and microbiota.
Enzymes are highly specific and will work on distinct substrates within particular pH ranges that can vary throughout the digestive tract according to a person’s diet and lifestyle. When properly formulated, supplemental digestive enzymes are able to facilitate the digestive process to break down offending food into smaller molecules, to allow the assimilation of nutrients and to reduce aggravation.
Experimental research into digestive enzyme activity suggests that an increase in enzymes via supplementation may neutralise or dramatically reduce the negative impact food of both intolerance and allergic reaction. [5] Digestive enzymes are therefore a popular therapeutic intervention for food intolerance protocols – particularly if accidental exposure is likely.
The role of enzymes in food intolerance.
Intolerances will most often manifest as gastrointestinal disturbance. Reported symptoms mimic those of other conditions and include altered bowel habits, abdominal pain, gastric discomfort, bloating, fatigue and headaches. [6] Diagnoses of IBS, fatigue, reflux, nausea, migraines or depression are frequent. Some patients will self-report an adverse reaction to a food however only 2% will be truly allergic.
Clinical diagnosis of intolerance is varied and unreliable. Laboratory tests for intolerances vary in validity. Hydrogen and methane breath testing is the most clinically regarded intolerance test for fructose, lactose and carbohydrate intolerance, and can accurately identify these intolerances in only 30% of those tested. Positive breath test results may lead to a misdiagnosis of SIBO. Frequently used but unvalidated intolerance tests include hair analysis, iridology, pulse tests, kinesiology, faecal microbial analysis, intestinal permeability and salivary IgA tests. Elimination diets remain the most reliable method for identifying an intolerance reaction, however such diets can be difficult for patient compliance. Persistent and chronic intolerance reactions can lead to excessive dietary restrictions and used long term may result in nutrient deficiency and reduced quality of life for the sufferer as well as increased risk of suffering from anxiety, depression and sleep disturbance.
Proteins
Gluten is the most prevalent of intolerance proteins. Proteins are hydrolysed by enzymes called proteases, proteolytic enzymes, proteinases, and peptidases. Gluten is formed of proteins that are proline rich making them difficult to digest. Effective breakdown of gluten’s peptide bonds are effectively hydrolysed by potent stomach acid, exopeptidases and endopeptidases. Gluten that survives the digestive tract without becoming hydrolysed will reach the small intestines where it can inflame, irritate and separate the intestinal villi. The resulting symptoms are brain fog, bloating and discomfort: intolerance but not allergy.
Dipeptidyl peptidase IV (DPP-IV) is an endogenous protease enzyme that has many different functions within the human body. In the digestive system, DP-IVV efficiently degrades gluten and casein. Taken supplementally, DPP-IV can break down gluten molecules into a digestible form whenever a client is accidently exposed to gluten, thus reducing the incidence of intolerance symptoms.
Carbohydrates
Carbohydrates form a large part of the modern diet. Many common carbohydrates contain a substrate called starch. Starch is digested by amylase to yield glucose. Whilst starch is effectively broken down by amylase, other enzymes are required to digest other carbohydrates effectively. As with proteins, undigested starch will provide fermentation food for microorganisms residing in the large intestine, creating excess gas and other metabolic complications over time. Supporting digestion with digestive enzymes can reduce occurrence and alleviate symptoms of intolerance.
Lactose is a sugar digested by lactase. It is estimated that 65% of humans have a genetically programmed down regulation of lactase that occurs after weaning. [7] Intolerance to lactose is almost always a result of deficiency of lactase and is experienced by the client as nausea, vomiting, abdominal pain, loose stools, flatulence and bowel sounds following the consumption of dairy products. Where there are low levels of lactase, lactose enters the intestinal lumen where it draws in water leading to the symptoms of intolerance.[8]
Cellulose is the main structural molecule in plant derived foods and a commonly ingested carbohydrate. The enzyme responsible for the breakdown of cellulose is cellulase. Cellulase is not produced by humans but is synthesised by micro-organisms in or outside of the body. Complete digestion of cellulose will yield glucose, and partially digested cellulose will feed probiotic bacteria in the gut. Consuming cellulase to facilitate the partial digestion of fibre will therefore benefit the flora of the gut.
Lipids
Lipids are small hydrophobic or amphipathic molecules. Inefficiency in digesting lipids in the diet commonly presents itself as steatorrhea. Sufficient lipid digestion requires healthy secretion of bile acids, digestive enzymes and a normally functioning gut mucosa. Digestive enzymes secreted from the liver, gall bladder, pancreas and stomach play a role in transporting lipids throughout the body. Nutrients like Vitamin A, E, D and K status may be affected, and malnutrition can occur. [9] Vulnerability in any part of this enzyme secretory system, such as gallbladder removal, will create an enzyme insufficiency that can be supported with supplemental enzymes to facilitate lipid digestion and subsequently all overall health. This occurrence can frequently be described by suffers as an intolerance reaction to lipid rich foods such as nuts, avocados or eggs and relieved with supplemental enzyme support. [10]
Supplemental enzymes in food intolerance
Supplemental enzymes are enzymes that are taken orally through the digestives system to facilitate the natural process of digestion. Where immune mediated allergic reaction is absent, digestive enzyme insufficiency could be a cause of an intolerance reactions to foods. Intolerance will most often manifest as gastrointestinal disturbance. Alongside elimination diets, pH balance and microbiome support, supplemental enzymes can provide support to patients who suffer intolerance reactions to foods.
Intolerance reactions can be triggered by multiple foods, so supplementing with digestive enzymes that facilitate better digestion of carbohydrates, proteins and fats together could provide a useful tool to protect clients from the negative consequences of accidental exposure to a trigger food whilst reducing the severity of intolerances overall as part of a wider digestive support protocol.
References
[1] Nutrition.org.uk. 2020. What Is Food Allergy And Intolerance? – British Nutrition Foundation. [online] Available at: <https://www.nutrition.org.uk/nutritionscience/allergy/what-is-food-allergy-and-intolerance.html> [Accessed 25 November 2020].
[2] Aziz, I., Lewis, N., Hadjivassiliou, M., Winfield, S., Rugg, N., Kelsall, A., Newrick, L. and Sanders, D., 2014. A UK study assessing the population prevalence of self-reported gluten sensitivity and referral characteristics to secondary care. European Journal of Gastroenterology & Hepatology, 26(1), pp.33-39.
[3] Tuck, C., Biesiekierski, J., Schmid-Grendelmeier, P. and Pohl, D., 2019. Food Intolerances. Nutrients, 11(7), p.1684.
[4] Cavaletti, L., Taravella, A., Carrano, L., Carenzi, G., Sigurtà, A., Solinas, N., Caro, S., Stasio, L., Picascia, S., Laezza, M., Troncone, R., Gianfrani, C. and Mamone, G., 2019. E40, a novel microbial protease efficiently detoxifying gluten proteins, for the dietary management of gluten intolerance. Scientific Reports, 9(1).
[5] Cavaletti, L., Taravella, A., Carrano, L., Carenzi, G., Sigurtà, A., Solinas, N., Caro, S., Stasio, L., Picascia, S., Laezza, M., Troncone, R., Gianfrani, C. and Mamone, G., 2019. E40, a novel microbial protease efficiently detoxifying gluten proteins, for the dietary management of gluten intolerance. Scientific Reports, 9(1).
[6] Aziz, I., Lewis, N., Hadjivassiliou, M., Winfield, S., Rugg, N., Kelsall, A., Newrick, L. and Sanders, D., 2014. A UK study assessing the population prevalence of self-reported gluten sensitivity and referral characteristics to secondary care. European Journal of Gastroenterology & Hepatology, 26(1), pp.33-39.
[7] Itan, Y., Jones, B., Ingram, C., Swallow, D. and Thomas, M., 2010. A worldwide correlation of lactase persistence phenotype and genotypes. BMC Evolutionary Biology, 10(1), p.36.
[8] Martínez Vázquez, S., Nogueira de Rojas, J., Remes Troche, J., Coss Adame, E., Rivas Ruíz, R. and Uscanga Domínguez, L., 2020. The importance of lactose intolerance in individuals with gastrointestinal symptoms. Revista de Gastroenterología de México (English Edition), 85(3), pp.321-331.
[9] Böhn, L., Störsrud, S., Törnblom, H., Bengtsson, U. and Simrén, M., 2013. Self-Reported Food-Related Gastrointestinal Symptoms in IBS Are Common and Associated With More Severe Symptoms and Reduced Quality of Life. American Journal of Gastroenterology, 108(5), pp.634-641.
[10] Zuvarox T, Belletieri C. Malabsorption Syndromes. [Updated 2020 Apr 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK553106/