• Animal protein intake at 12 months is associated with growth factors at the age of six.

      Thorisdottir, Birna; Gunnarsdottir, Ingibjorg; Palsson, Gestur Ingvi; Halldorsson, Thorhallur Ingi; Thorsdottir, Inga; Landspitali Univ Hosp, Unit Nutr Res, IS-101 Reykjavik, Iceland, Univ Iceland, Sch Hlth Sci, Fac Food Sci & Nutr, IS-101 Reykjavik, Iceland, Landspitali Univ Hosp, Childrens Hosp, IS-101 Reykjavik, Iceland (Wiley-Blackwell, 2014-05)
      To study the associations between protein intake from different sources with anthropometry and serum insulin-like growth factor 1 (IGF-1) in infancy and childhood.
    • Assessing validity of a short food frequency questionnaire on present dietary intake of elderly Icelanders.

      Eysteinsdottir, Tinna; Thorsdottir, Inga; Gunnarsdottir, Ingibjorg; Steingrimsdottir, Laufey; Unit for Nutrition Research, University of Iceland and Landspitali National-University Hospital, Reykjavik, Iceland (2012)
      Few studies exist on the validity of food frequency questionnaires (FFQs) administered to elderly people. The aim of this study was to assess the validity of a short FFQ on present dietary intake, developed specially for the AGES-Reykjavik Study, which includes 5,764 elderly individuals. Assessing the validity of FFQs is essential before they are used in studies on diet-related disease risk and health outcomes. 128 healthy elderly participants (74 y ± 5.7; 58.6% female) answered the AGES-FFQ, and subsequently filled out a 3-day weighed food record. Validity of the AGES-FFQ was assessed by comparing its answers to the dietary data obtained from the weighed food records, using Spearman's rank correlation, Chi-Square/Kendall's tau, and a Jonckheere-Terpstra test for trend. For men a correlation ≥ 0.4 was found for potatoes, fresh fruits, oatmeal/muesli, cakes/cookies, candy, dairy products, milk, pure fruit juice, cod liver oil, coffee, tea and sugar in coffee/tea (r = 0.40-0.71). A lower, but acceptable, correlation was also found for raw vegetables (r = 0.33). The highest correlation for women was found for consumption of rye bread, oatmeal/muesli, raw vegetables, candy, dairy products, milk, pure fruit juice, cod liver oil, coffee and tea (r = 0.40-0.61). An acceptable correlation was also found for fish topping/salad, fresh fruit, blood/liver sausage, whole-wheat bread, and sugar in coffee/tea (r = 0.28-0.37). Questions on meat/fish meals, cooked vegetables and soft drinks did not show a significant correlation to the reference method. Pearson Chi-Square and Kendall's tau showed similar results, as did the Jonckheere-Terpstra trend test. A majority of the questions in the AGES-FFQ had an acceptable correlation and may be used to rank individuals according to their level of intake of several important foods/food groups. The AGES-FFQ on present diet may therefore be used to study the relationship between consumption of several specific foods/food groups and various health-related endpoints gathered in the AGES-Reykjavik Study.
    • Associations of iron status with dietary and other factors in 6-year-old children

      Gunnarsson, B S; Thorsdottir, I; Palsson, G (Nature Publishing Group, 2007-03-01)
      OBJECTIVE: To investigate the associations of iron status at 6 years of age with dietary and other factors. DESIGN: In a cross-sectional study, children's dietary intakes (3-day weighed food record) were recorded, body size was measured and blood samples were taken near their sixth birthday. SUBJECTS: A sample of 188 children, from two previous studies (cohorts 1 and 2), was contacted, and 139 (74%) agreed to participate. RESULTS: Multiple regression analyses with dietary and other factors showed that meat and fish consumption, multivitamin/mineral supplement intake (both positively) and cow's milk product consumption (negatively) were associated with log serum ferritin (SF) (adjusted R (2)=0.125; P=0.028; n=129), and juices and residence (rural>urban) with haemoglobin (Hb) (adjusted R (2)=0.085; P=0.034; n=127). Of 21 multivitamin/mineral consumers, none had depleted iron stores compared to 21 iron-depleted of 108 non-consumers (P=0.024). Children living in rural areas (<10,000 inhabitants) (n=33) had higher mean corpuscular volume (MCV) (83.3+/-2.3 fl) than those living in urban areas (>10,000 inhabitants) (82.1+/-3.2 fl; n=103) (P=0.048). Multiple regression analyses with dietary and other factors and growth showed in cohort 1 that residence (rural>urban), weight gain 0-1years (negatively), and meat and fish intake (positively) were associated with Hb (adjusted R (2)=0.323; P=0.030; n=51), meat and fish (positively) with both log SF (adjusted R (2)=0.069; P=0.035; n=52) and MCV (adjusted R (2)=0.064; P=0.035; n=52), and in cohort 2 cow's milk product consumption (negatively) was associated with log SF (adjusted R (2)=0.119; P=0.017; n=41) and residence (rural>urban) with MCV (adjusted R (2)=0.102; P=0.025; n=41). CONCLUSIONS: Consumption of meat and fish and possibly also juices, as well as multivitamin/mineral intake might affect iron status in 6-year-old children positively, whereas cow's milk product consumption might affect iron status negatively. Slower growth in the first year of life and rural residence are positively related to iron status of 6-year-olds.
    • Dietary intake of 10- to 16-year-old children and adolescents in central and northern Europe and association with the incidence of type 1 diabetes

      Thorsdottir, I; Ramel, A (Karger, 2003-11-01)
      BACKGROUND/AIMS: The highest incidence of type 1 diabetes is among 10- to 15-year-old adolescents. The aim of this study was to investigate a possible relationship between the dietary intake of this group and the incidence of type 1 diabetes. METHODS: Dietary intake data of 10- to 16-year-old adolescents (n = 4,701) from 11 European countries and the incidence rates of type 1 diabetes were used to examine the relation between food and the disease. RESULTS: The incidence of type 1 diabetes correlated with the consumption of total fat (r = 0.674; p = 0.023), saturated fatty acids (r = 0.714; p = 0.047) and the intake of fruits and vegetables (r = 0.786; p = 0.036). Fruit intake or vegetable intake alone did not correlate with the incidence. Cow's milk and animal product consumption correlated with the incidence when Icelandic data were excluded (r = 0.829; p = 0.042 and r = 0.999; p = 0.001). A negative correlation of borderline significance was found between sugar intake and the incidence of type 1 diabetes (r = -0.721; p = 0.068). CONCLUSION: The results indicate for the first time that an adolescent's diet high in fat and fruits and vegetables is associated with an increased risk of type 1 diabetes. Fruit or vegetable intake separately was not associated with type 1 diabetes. It is important to characterize and minimize diabetogenic factors in fruits and vegetables as the general health benefits of a diet rich in fruits and vegetables are well known and such a diet is therefore recommended. This study supports previous research about the importance of cow's milk and animal products in the aetiology of type 1 diabetes.
    • Differences in cow's milk composition between Iceland and the other Nordic countries and possible connections to public health

      Iggman, D; Birgisdottir, B; Ramel, A; Thorsdottir, I; Hill, J (Informa Healthcare, 2003-12-01)
      Background: The Icelandic bovine herd has been isolated for over 1100 years. Knowledge is needed about how its milk constituents differ from those of milk in the other Nordic countries, where cattle have been interbred with other European races. As milk and dairy products comprise a substantial part of food intake, especially in children, variations in cow's milk composition may be of value when considering environmental factors in public health. Regional variation in milk composition may explain contradictory results from studies on milk consumption and aetiology of diseases, type 1 diabetes mellitus and cardiovascular disease. Objective: To investigate differences in milk composition, particularly substances suggested to influence public health. Design: Analyses of the proteins ß-casein and ß-lactoglobulin, as well as fatty acid profiles and nitrates, were performed in samples of cow's milk as sold to consumers, at four different times during 1 year in three different regions in Iceland and in the capital areas of the other countries. Results: The Icelandic milk was significantly (p<0.05) lower in ß-casein fractions A1 and B and higher in the A2 fraction, lower in ß-lactoglobulin B and higher in A (p<0.001), had less than half in n-6/n-3 ratio and was higher in the very long-chain n-3 fatty acids and conjugated linoleic acid. It was slightly higher in saturated fatty acids. No significant difference was seen in the total amount of ß-caseins, ß-lactoglobulins or nitrates. Conclusions: Although slightly higher in saturated fatty acids, the Icelandic milk has a composition of proteins and fatty acids that may be associated with health benefits.
    • Effects of a healthy Nordic diet on plasma 25-hydroxyvitamin D concentration in subjects with metabolic syndrome: a randomized, placebo-controlled trial (SYSDIET).

      Brader, Lea; Rejnmark, Lars; Carlberg, Carsten; Schwab, Ursula; Kolehmainen, Marjukka; Rosqvist, Fredrik; Cloetens, Lieselotte; Landin-Olsson, Mona; Gunnarsdottir, Ingibjorg; Poutanen, Kaisa S; et al. (Springer, 2014-06)
      At northern latitudes, vitamin D is not synthesized endogenously during winter, causing low plasma 25-hydroxyvitamin D (25(OH)D) concentrations. Therefore, we evaluated the effects of a healthy Nordic diet based on Nordic nutrition recommendations (NNR) on plasma 25(OH)D and explored its dietary predictors.
    • Iodine status of adolescent girls in a population changing from high to lower fish consumption

      Gunnarsdottir, I; Gunnarsdottir, B E; Steingrimsdottir, L; Maage, A; Johannesson, A J; Thorsdottir, I; [1] Unit for Nutrition Research, University of Iceland & Landspitali University Hospital, Reykjavik, Iceland [2] Faculty of Food Science and Human Nutrition, School of Health Sciences, University of Iceland, Reykjavik, Iceland. (Nature Publishing Group, 2010-09-01)
      Objectives:During the last decades, fish and milk consumption has decreased considerably in Iceland, especially among adolescents. As these food items are important dietary iodine (I) sources, the aim of the study was to assess the iodine status and dietary pattern of adolescent girls in a population changing from a high to lower consumption of milk and fish.Subjects/Methods:Subjects were randomly selected adolescent girls (16-20 years old, n=112). A validated Food Frequency Questionnaire (FFQ) was used to evaluate food consumption and compare it with food-based dietary guidelines for milk and dairy products (2-3 portions/day) and fish (>/=2 times/week). Urine samples were collected for measuring urinary iodine (U-I) and creatinine (Cr) and blood samples for measuring serum thyroid-stimulating hormone (TSH).Results:Milk and dairy products provided 43% and fish provided 24% of the total dietary I. More than 65% of the girls consumed fish less than twice a week, and 40% consumed less than two portions of milk and dairy products per day. The median U-I concentration was 200 mug/l and the U-I/Cr ratio 138 mug I/g Cr. High intake of milk was associated with higher urinary iodine concentration, but fish intake was not found to be directly associated with urinary iodine concentration.Conclusions:Iodine status of Icelandic adolescent girls is within the optimal range defined by the World Health Organization. It is important to monitor both iodine status and the iodine concentration of important sources of iodine, as both dietary habits and composition of food might change with time.
    • Iodine status of pregnant women in a population changing from high to lower fish and milk consumption.

      Gunnarsdottir, Ingibjorg; Gustavsdottir, Anita G; Steingrimsdottir, Laufey; Maage, Amund; Johannesson, Ari J; Thorsdottir, Inga; Univ Iceland, Unit Nutr Res, Reykjavik, Iceland, Univ Iceland, Fac Food Sci & Nutr, IS-101 Reykjavik, Iceland, Natl Inst Nutr & Seafood Reasearch NIFES, Bergen, Norway, Univ Hosp, Landspitali, Dept Endocrinol & Metab, Reykjavik, Iceland (Cambridge Univ Press, 2013-02)
      Pregnancy is one of the most critical periods for iodine deficiency. The aim of the present study was to assess the iodine status and dietary intake of pregnant women in a population changing from high to lower consumption of milk and fish.
    • Lower consumption of cow milk protein A1 beta-casein at 2 years of age, rather than consumption among 11- to 14-year-old adolescents, may explain the lower incidence of type 1 diabetes in Iceland than in Scandinavia

      Birgisdottir, B E; Hill, J P; Thorsson, A V; Thorsdottir, I (Karger, 2006-05-01)
      AIM: To compare the consumption of the cow milk proteins A1 and B beta-casein among children and adolescents in Iceland and Scandinavia (Norway, Denmark, Sweden and Finland) as this might explain the lower incidence of type 1 diabetes (per 100,000/year, 0-14 years) in Iceland. METHODS: The consumption of A1 beta-casein in each country among 2- and 11- to 14-year-old children was calculated from results on food intake and on cow milk protein concentration. The consumption values were then compared and evaluated against the incidence of type 1 diabetes. RESULTS: There was a significant difference between the consumption of A1 (p = 0.034) as well as the sum of A1 and B (p = 0.021) beta-casein in Iceland and Scandinavia for 2-year-old children. In the same age group, consumption of A1 beta-casein correlated with the incidence of type 1 diabetes in the countries (r = 0.9; p = 0.037). No significant difference in consumption of A1 or the sum of A1 and B beta-casein was found for 11- to 14-year-old adolescents. CONCLUSION: This study supports that lower consumption of A1 beta-casein might be related to the lower incidence of type 1 diabetes in Iceland than in Scandinavia. Additionally it indicates that consumption in young childhood might be of more importance for the development of the disease incidence than consumption in adolescence.