Increased heavy metal intake through a gluten-free diet?
More and more people are refraining from gluten, even if they do not suffer from gluten intolerance or celiac disease. A recent study suggests that this increases their intake of heavy metals, albeit in an area that is not supposed to be harmful to health.
Many of the gluten-free foods that are consumed instead of wheat and other cereals containing gluten are often contaminated with heavy metals. It is known, for example, that rice or rice products have too high arsenic values and sea fish have relatively high mercury concentrations.
The US study authors now wanted to know whether this affects the gluten-free diet. To do this, they evaluated the National Health and Nutrition Examination Survey (NHANES) data. As part of the NHANES survey, around 5000 representatively selected US citizens are asked about their eating habits and asked for blood and urine samples. The research team evaluated the measurement results of almost 12,000 respondents who took part in the survey between 2009 and 2012. Arsenic measurements of 4000 people were present in the urine. 32 people said they had a gluten-free diet. Lead, mercury and cadmium had been determined in more than 11,300 people in the serum, 115 of whom indicated a gluten-free diet.
It was shown that people on a gluten-free diet compared to those on a gluten-free diet had significantly higher blood levels of mercury, lead and cadmium. The arsenic levels in the urine were also increased. The values hardly differed between people with and without celiac disease, provided they did not use gluten. This points to the diet as the cause of the increased concentrations.
However, the very few of the heavy metals were of health concern. Fish consumption proved to be the main reason for the increased mercury levels. However, the researchers point out that this could also be caused by the reduced protein and especially sulfur content that goes with gluten-free diets. Since sulfur-containing amino acids are necessary to bind heavy metals, their deficiency could also lead to increased serum metal levels. Cadmium levels were three times higher in smokers - whether with or without a gluten-containing diet - than in non-smokers.