Sucrose Rich Foods and Sucrose Intolerance

Introduction

Sucrose is a common sugar, also known as cane sugar or saccharose. It is a disaccharide, being an equal combination of two monosaccharides: glucose and fructose. In nature, sucrose is produced in plants through photosynthesis. Later, humans extract the sucrose from the plants and process it into the white sugar that we know. The name “sugar” or “sucre” in French originates from the word sucrose.

Recommendations

Based on guidelines by the World Health Organisation (WHO) daily intake of free sugars, for both children and adults, should be less than 10% of their total energy intake, which is equal to roughly 200 calories for an average adult. A further reduction to below 5% or roughly 25 grams (6 teaspoons) per day would provide additional health benefits (1). Overusing sucrose is a risk factor for the development of metabolic syndrome, including type 2 diabetes, hypertension and obesity.

Metabolism in the Body

When sucrose is consumed, it reaches all the way to the duodenum without changing its form. In the duodenum’s microvilli sucrose is broken down into separate molecules of fructose and glucose by the enzyme named sucrase-isomaltase, and absorbed into the bloodstream. Due to this, sucrose tends to elevate blood glucose levels quickly. However, it has a medium glycemic index of 65 (2).

Sucrose Intolerance

Sucrose intolerance is the inability of sucrose breakdown by the small intestine. Sucrose intolerance can be primary or secondary. Primary sucrose intolerance is also called congenital or genetic sucrase-isomaltase deficiency (CSID or GSID). As the name implies, people with this condition lack the enzymes sucrase and isomaltase that are responsible for digesting sucrose. This condition can be caused by many mutations in the sucrose gene that can occur on either sucrase or isomaltase units, resulting in varying activities of the sucrase-isomaltase enzyme (3).

Secondary or acquired sucrase-isomaltase deficiency is more often caused by the atrophy of small intestinal villi due to various chronic diseases, such as Celiac’s disease, Crohn's disease, chemotherapy, allergic enteropathy, immunodeficiency and others. Acquired sucrose intolerance can also occur due to infections or motor dysfunctions of the gastrointestinal tract (3).

Sucrose Intolerance Symptoms

Regardless of the cause of sucrose intolerance, the clinical symptoms are the same. However the severity of the symptoms can depend on the lack of the enzymes or the level of intestinal dystrophy in the small intestine.

Because sucrose has an osmotic effect, the accumulation of it in the intestinal lumen causes the liquid to stay in the intestines. This leads to hyperosmolar diarrhea. The undigested sucrose reaching the bacteria in the colon, goes through the process of bacterial fermentation. This process releases gases in the colon, causing bloating, abdominal pain and flatulence. Constant diarrhea can lead to malabsorption and weight loss.

There can also be atypical symptoms, such as vomiting, alteration between diarrhea and constipation, anxiety, heart palpitations.

Due to the shorter length of the small intestine, children are more susceptible to symptoms. Therefore, symptoms can improve with age (3).

For people with sucrose intolerance, it may be imperative to modify their diets and exclude or lower their sucrose intake. Therefore, it is important to know which foods contain high levels of sucrose.

Sources.

1. https://www.who.int/mediacentre/news/releases/2015/sugar-guideline/en/
2. https://care.diabetesjournals.org/content/diacare/suppl/2008/09/18/dc08-1239.DC1/TableA1_1.pdf
3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4746203/