Iron stores in relation to dietary patterns in a multiethnic population: the SAMINOR study

Objective: We evaluated the association between serum ferritin (s-ferritin), transferrin saturation and dietary patterns, in connection with ethnicity, geographical settlement and lifestyle factors. Design: In 2003-2004, a cross-sectional study of health and living conditions was carried out in northern Norway. Setting: A questionnaire explored, among other factors, ethnicity and food consumption habits. Principal component analysis was used to assess the association between variables. Seven principal components were then used as input to a cluster analysis. To characterise food consumptions, five dietary patterns were identified and used to assess the effect of food consumption habits on Fe stores. Subjects: A total of 16 323 men and women between the ages of 36 and 79 years participated. Results: Participants who frequently consumed reindeer meat had higher levels of s-ferritin (P<0.0001) than did individuals with other dietary patterns. This pattern was highly represented by subjects with three generations of Sami language (Sami I). Further, mean transferrin saturation in the reindeer group was higher compared with the other dietary clusters for men (P<0.04) and women (P<0.02). However, the reindeer pattern individuals also had the highest proportion of subjects with overweight and obesity. Obesity was positively associated with s-ferritin in both men and women (P<0.0001). Conclusions: The differences in Fe status described earlier between inland Sami and non-Sami can be explained by several factors such as food habits, age and obesity. High level of s-ferritin may reflect high intake of reindeer meat. Being overweight and obese is also associated with s-ferritin levels.