More and more people avoid gluten, whether they suffer from gluten intolerance or celiac disease or not. A recent study indicates that the gluten-free diet increases the intake and the poor metabolism of heavy metals.
Some gluten-free foods could be the culprits
Many of the gluten-free foods that are consumed instead of wheat and other gluten-containing grains are often contaminated with heavy metals.
It is known, for example, that rice or rice-related products have arsenic values which are very high. Besides, some seafood presents relatively high mercury concentrations.
The US study authors evaluated the National Health and Nutrition Examination Survey (NHANES) data
As part of the NHANES survey, around 5000 US citizens were surveyed every year to check their dietary habits and to offer blood and urine samples. The research team evaluated the results of almost 12,000 respondents who participated in these surveys between 2009 and 2012.
Lead, mercury, and cadmium have been determined in blood and urine samples in over 11,300 people, 115 of whom followed a gluten-free diet.
It was found that people with gluten-free diet present significantly higher blood levels of mercury, lead, and cadmium in comparison with the participants who opted for a regular diet.
High arsenic levels have also been discovered
The arsenic levels were also elevated in the urine sample of those who opted for a gluten-free diet.
However, the values hardly differed between persons suffering or not from celiac disease, as long as they did follow a diet lacking in gluten. This indicates this type of diet as the cause of the increased arsenic concentrations.
The main reason for the increased mercury levels proved to be the seafood consumption.
The researchers noted, however, that these could also be caused by the reduced protein and especially sulfur content associated with gluten-free diets. Since sulfur-containing amino acids are needed to bind heavy metals, their deficiency could also lead to increased serum-metal levels.
On the other hand, cadmium levels were three times higher in smokers, whether they’ve followed a gluten-free diet or not.