A gluten-free diet: is it healthy or harmful?

A crossed-out head of grain – lately this symbol has been marking more and more food products as gluten-free. Not only are they found on supermarket shelves, but restaurants are also increasingly serving gluten-free versions of popular classics. But where has this sudden interest in the gluten-free diet come from?

Few other food ingredients have become as discreditable as gluten in recent years. Especially in Western countries, there are many voices that propagate its harmfulness, instead of claiming that eating gluten-free has beneficial effects to our health. Simultaneously with the growing media attention, the number of people who eat gluten-free foods is also steadily rising.

An evaluation of the US National Health and Nutrition Examination Surveys from 2009 to 2014, showed that the number of respondents who refrain from gluten more than tripled. Similar tendencies can be observed in a large number of other countries as well.

Is gluten really as bad as its reputation? Also known as gluten protein, gluten is a protein mixture that naturally occurs within the seeds of many cereals (wheat, rye, barley, spelt). There it serves as a storage for amino acids and proteins, which are needed for the plant to grow properly. In addition, the protein plays a central role in the food manufacturing. If the gluten contained in cereal flour mixes with water, it turns into a malleable, elastic mass - the dough.

Contrary to what is often reported, gluten has not been shown to be harmful to the general population. People who suffer from gluten-sensitive enteropathy or celiac disease, are a rare exception. Only about one percent of the world's population are affected by this immune-mediated intolerance, which causes the body to develop antibodies both against the components of the gluten as well as against the body’s own cells. As a result, eating gluten-containing foods leads to chronic inflammation and damage to the intestinal mucosa. Frequently those affected suffer from different symptoms, such as headaches, lethargy, loss of appetite, gastrointestinal discomfort and stool changes.

As the disease progresses, deficiencies, weight loss and the development of malignant tumors of the small intestine can develop. However, the aforementioned general symptoms are not sufficient for the diagnosis of celiac disease. For a proper diagnosis, specific antibodies within the blood and small intestine must be verified by biopsy. Once the diagnosis has been made, the only effective therapy for patients is to abstain from gluten for the rest of their lives.

While the number of those suffering from celiac disease remains largely constant, more and more people are becoming gluten-free in the belief that they are ill. One possible explanation is the non-celiac gluten sensitivity (NCGS). In this case, sufferers without the presence of celiac disease-specific findings show similar symptoms, which can be significantly alleviated by a gluten-free diet.

The underlying pathomechanisms of NCGS have not yet been clarified, with gluten and other constituents of cereals as the cause. Due to the lack of a general definition, it is currently a diagnosis by exclusion. Yet, those affected often diagnose themselves without appropriate tests.


A recently published Norwegian study raises doubts about the validity of such self-diagnosis. For this study, self-diagnosed NCGS patients ate gluten-free and gluten-containing muffins at different times. Without knowing which muffin they were eating, most subjects reported stronger symptoms from the gluten-free variety. Only a few participants were able to confirm their NCGS suspicions. The authors of the study further discussed the patients’ strong reactions to other ingredients as a possible cause of their results.

While abstaining from gluten-containing foods is a compulsory part of the treatment for celiac patients and may be useful for people with wheat or gluten sensitivities, it is generally not recommended for healthy individuals.

The increasing popularity of gluten-free foods should be regarded as a food trend, as well as a successful result of extensive advertising efforts by the food industry.

In addition, a gluten-free diet is not necessarily healthy. Many products contain more fat and less vitamins as well as less fibers and minerals. Researchers at Harvard Medical School and Columbia University even proved that avoiding gluten can negatively impact our general nutrition and increase cardiovascular risk.

Ultimately, grain products are the basis of a balanced diet and a life without bread and pasta is only necessary, or even desirable, in a few exceptional cases.

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