Food intolerances are an adverse reaction of the body to certain foods or ingredients consumed in the diet. Unlike food allergies, food intolerances usually involve a milder response and can be caused by different factors. Examples include a lack of an enzyme needed to digest a food or moderate activation of the immune system. Common food intolerances include gluten, lactose and fructose intolerance.
Food intolerances can cause a wide variety of symptoms. The most common symptoms are nausea, abdominal pain, diarrhea, constipation, bloating, gas, fatigue, headaches and skin rashes. Although these symptoms are usually less severe than those of a food allergy, can significantly affect a person's quality of life..
In this post, we will talk in detail about gluten, lactose, and fructose intolerance. These three nutrients are found in different foods and are the three most common types of intolerance.
Gluten intolerance
Gluten is a protein present in certain cereals, such as wheat, barley and rye. In individuals with gluten intolerance, its consumption can cause damage to the lining of the small intestine, as well as other symptoms such as abdominal discomfort, diarrhea, fatigue, and growth disturbances in the case of children.
There are varying degrees of gluten intolerance. The most severe is celiac disease (CD), a chronic inflammatory pathology that occurs as a result of this gluten intolerance. When ingesting this protein, the immune system reacts as if it were a foreign substance and damages the lining of the small intestine. This triggers the infiltration of inflammatory cells into the intestine. This can interfere with nutrient absorption and cause severe villi damage to the intestinal mucosa.
Other cases of gluten intolerance are called gluten intolerance. non-celiac gluten sensitivity (NCGS). People with this condition may experience symptoms similar to those of celiac disease, such as abdominal pain, diarrhea and fatigue. The difference between the two conditions lies in changes in the lining of the small intestine (does not occur in people with NCGS). It is thought that this sensitivity may be related to an abnormal immune response to gluten, although the specific mechanisms associated with its occurrence are not yet known.
Gluten intolerance has a strong genetic predisposition, which means that certain genes can increase the risk of developing this condition. The most commonly associated haplotypes are HLA-DQ2 and HLA-DQ8.
These genetic markers are located on chromosome 6 and are involved in the presentation of proteins to the immune system. Most people with CD, about 95%, have a variant of this gene known as DQ2.5, which is considered the main genetic risk factor for the disease. The remaining 5% usually have HLA-DQ8.
These markers are found in about 30% in the apparently healthy general population, so having these markers is a necessary, but not determinant, condition for developing gluten intolerance. In people with NCGS, the frequency of these markers is higher than in the general population, but much lower than in CD, around 50%.
In summary, gluten can cause problems in some people due to an abnormal immune response that can lead to damage to the small intestine and other symptoms. If gluten intolerance or sensitivity is suspected, it is important to talk to a doctor and nutritionist to make an accurate diagnosis with all recommended tests, including genetic predisposition.
Lactose intolerance
Lactose is a carbohydrate found naturally in milk and milk products. Those who are lactose intolerant cannot digest this sugar properly due to a deficiency in the production of the enzyme lactase. As a result, they may experience symptoms such as abdominal discomfort, bloating, and diarrhea after eating foods containing this sugar.
It is known that lactose intolerance has a clear genetic predisposition associated with the MCM6 gene. This gene is located near the lactase gene on chromosome 2. The most common variant of the MCM6 gene, called -13910 C/T, has been strongly associated with lactase production in adulthood and thus with the ability to digest lactose.
This variant has been found to control lactase production in humans. This variant has been associated with increased lactase production in adulthood, allowing people to digest the lactose in dairy products. On the contrary, not presenting this variant predisposes to a lower production of lactase, and therefore, a lower capacity to digest lactose.
Therefore, this variant of the MCM6 gene has been used as a useful genetic marker to predict a person's ability to digest lactose, and thus identify lactose intolerance.
Fructose intolerance
Fructose is a carbohydrate present both in various fruits and in processed products such as soft drinks, syrups and prepared foods. People suffering from fructose intolerance may experience abdominal discomfort, bloating and diarrhea after eating foods containing this type of sugar.
There are different types of fructose intolerance. There is a genetic disease, called hereditary fructose intolerance (IHF), that affects the body's ability to process and metabolize fructose. IHF is caused by mutations in the ALDOB gene, which provides instructions for the production of the enzyme aldolase B needed to break down fructose in the liver.
These mutations can affect the production, stability or activity of the enzyme, leading to partial or total deficiency of the enzyme. This leads to the accumulation of fructose and its metabolites in the body, causing the aforementioned symptoms.
If any food intolerance is suspected, it is important to consult a doctor and nutritionist to obtain an accurate diagnosis along with appropriate recommendations for adapting the diet.
Now you can discover your genetic predisposition to gluten, lactose and fructose intolerance along with many other nutritional traits in ADNTRO. What are you waiting for to get to know yourself better?
