In a recent study entitled “High Prevalence of Nickel Allergy in an Overweight Female Population: A Pilot Observational Analysis” authors identified overweight female patients exhibit increased prevalence of nickel allergy, arising due to exposure to nickel-high concentrations, and that a low nickel diet reduces patients’ Body Mass Index and waist circumference. The study was published in the open-access journal PLOS One.
Nickel is a natural element that is commonly found in the water and soil, but also in plants. Dietary nickel consumption is actually mainly due to plant-based foods. While nickel is essential in small quantities, exposure to high concentrations causes skin sensitization. A more systemic condition, called Nickel allergy, is characterized by cutaneous but also systemic symptoms, affecting the gastrointestinal mucosa.
In this study, the authors noted a particular high prevalence of Nickel allergy in overweight individuals when compared to the general population. The aim of the study was to evaluate nickel allergy incidence in overweight subjects and determine the implications to patients’ health upon exposure to a low nickel diet. To this end, the team enrolled eighty-seven (87) overweight subjects, 15 males and 72 females, diagnosed with high Body Mass Index (BMI), of more than >26 Kg/m2. The team screened the cohort of patients for nickel allergy. Additionally, the team determined several anthropometric measurements, including height, weight, BMI, waist circumference but also blood pressure and liver panels, fasting glucose, insulin, total cholesterol and triglycerides.
Overweight patients diagnosed with nickel allergy were prescribed a low nickel diet (80–100 µg/daily). The diet plan was developed according to previous published guidelines, and included food with low nickel content. Accordingly, legumes, soy, whole-grain products were excluded and other vegetables consumption, including tomatoes, cauliflower, carrots, onions, spinach and lettuce restricted. Patients on low nickel diet, specifically forty-three (43) women and two (2) men, were followed during 6 months and the team determined changes in patients BMI and waist circumference.
The team identified nickel allergy was prevalent in 59.7% of overweight females, while in general population the numbers were much lower (12.5%), specifically in overweight women with metabolic syndrome and fatty liver disease. Upon exposure to low nickel diet, a significant decrease in patients’ BMI and waist circumference, detected already within three months of the diet (and was maintained until the end of the study, i.e., six months). The team highlight their results are still preliminary and further research is needed to support their findings, and further assess the role of nickel in obesity.